diff --git a/vendor/github.com/Shopify/sarama/.gitignore b/vendor/github.com/Shopify/sarama/.gitignore
new file mode 100644
index 0000000..6e362e4
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/.gitignore
@@ -0,0 +1,27 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+*.test
+
+# Folders
+_obj
+_test
+.vagrant
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+
+coverage.txt
+profile.out
diff --git a/vendor/github.com/Shopify/sarama/.travis.yml b/vendor/github.com/Shopify/sarama/.travis.yml
new file mode 100644
index 0000000..cace313
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/.travis.yml
@@ -0,0 +1,37 @@
+dist: xenial
+language: go
+go:
+- 1.12.x
+- 1.13.x
+
+env:
+  global:
+  - KAFKA_PEERS=localhost:9091,localhost:9092,localhost:9093,localhost:9094,localhost:9095
+  - TOXIPROXY_ADDR=http://localhost:8474
+  - KAFKA_INSTALL_ROOT=/home/travis/kafka
+  - KAFKA_HOSTNAME=localhost
+  - DEBUG=true
+  matrix:
+  - KAFKA_VERSION=2.2.1 KAFKA_SCALA_VERSION=2.12
+  - KAFKA_VERSION=2.3.0 KAFKA_SCALA_VERSION=2.12
+
+before_install:
+- export REPOSITORY_ROOT=${TRAVIS_BUILD_DIR}
+- vagrant/install_cluster.sh
+- vagrant/boot_cluster.sh
+- vagrant/create_topics.sh
+- vagrant/run_java_producer.sh
+
+install: make install_dependencies
+
+script:
+- make test
+- make vet
+- make errcheck
+- if [[ "$TRAVIS_GO_VERSION" == 1.13* ]]; then make fmt; fi
+
+after_success:
+- go tool cover -func coverage.txt
+- bash <(curl -s https://codecov.io/bash)
+
+after_script: vagrant/halt_cluster.sh
diff --git a/vendor/github.com/Shopify/sarama/CHANGELOG.md b/vendor/github.com/Shopify/sarama/CHANGELOG.md
new file mode 100644
index 0000000..844f481
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/CHANGELOG.md
@@ -0,0 +1,867 @@
+# Changelog
+
+#### Version 1.25.0 (2020-01-13)
+
+New Features:
+- Support TLS protocol in kafka-producer-performance
+  ([1538](https://github.com/Shopify/sarama/pull/1538)).
+- Add support for kafka 2.4.0
+  ([1552](https://github.com/Shopify/sarama/pull/1552)).
+
+Improvements:
+- Allow the Consumer to disable auto-commit offsets
+  ([1164](https://github.com/Shopify/sarama/pull/1164)).
+- Produce records with consistent timestamps
+  ([1455](https://github.com/Shopify/sarama/pull/1455)).
+
+Bug Fixes:
+- Fix incorrect SetTopicMetadata name mentions
+  ([1534](https://github.com/Shopify/sarama/pull/1534)).
+- Fix client.tryRefreshMetadata Println
+  ([1535](https://github.com/Shopify/sarama/pull/1535)).
+- Fix panic on calling updateMetadata on closed client
+  ([1531](https://github.com/Shopify/sarama/pull/1531)).
+- Fix possible faulty metrics in TestFuncProducing
+  ([1545](https://github.com/Shopify/sarama/pull/1545)).
+
+#### Version 1.24.1 (2019-10-31)
+
+New Features:
+- Add DescribeLogDirs Request/Response pair
+  ([1520](https://github.com/Shopify/sarama/pull/1520)).
+
+Bug Fixes:
+- Fix ClusterAdmin returning invalid controller ID on DescribeCluster
+  ([1518](https://github.com/Shopify/sarama/pull/1518)).
+- Fix issue with consumergroup not rebalancing when new partition is added
+  ([1525](https://github.com/Shopify/sarama/pull/1525)).
+- Ensure consistent use of read/write deadlines
+  ([1529](https://github.com/Shopify/sarama/pull/1529)).
+
+#### Version 1.24.0 (2019-10-09)
+
+New Features:
+- Add sticky partition assignor
+  ([1416](https://github.com/Shopify/sarama/pull/1416)).
+- Switch from cgo zstd package to pure Go implementation
+  ([1477](https://github.com/Shopify/sarama/pull/1477)).
+
+Improvements:
+- Allow creating ClusterAdmin from client
+  ([1415](https://github.com/Shopify/sarama/pull/1415)).
+- Set KafkaVersion in ListAcls method
+  ([1452](https://github.com/Shopify/sarama/pull/1452)).
+- Set request version in CreateACL ClusterAdmin method
+  ([1458](https://github.com/Shopify/sarama/pull/1458)).
+- Set request version in DeleteACL ClusterAdmin method
+  ([1461](https://github.com/Shopify/sarama/pull/1461)).
+- Handle missed error codes on TopicMetaDataRequest and GroupCoordinatorRequest
+  ([1464](https://github.com/Shopify/sarama/pull/1464)).
+- Remove direct usage of gofork
+  ([1465](https://github.com/Shopify/sarama/pull/1465)).
+- Add support for Go 1.13
+  ([1478](https://github.com/Shopify/sarama/pull/1478)).
+- Improve behavior of NewMockListAclsResponse
+  ([1481](https://github.com/Shopify/sarama/pull/1481)).
+
+Bug Fixes:
+- Fix race condition in consumergroup example
+  ([1434](https://github.com/Shopify/sarama/pull/1434)).
+- Fix brokerProducer goroutine leak
+  ([1442](https://github.com/Shopify/sarama/pull/1442)).
+- Use released version of lz4 library
+  ([1469](https://github.com/Shopify/sarama/pull/1469)).
+- Set correct version in MockDeleteTopicsResponse
+  ([1484](https://github.com/Shopify/sarama/pull/1484)).
+- Fix CLI help message typo
+  ([1494](https://github.com/Shopify/sarama/pull/1494)).
+
+Known Issues:
+- Please **don't** use Zstd, as it doesn't work right now.
+  See https://github.com/Shopify/sarama/issues/1252
+
+#### Version 1.23.1 (2019-07-22)
+
+Bug Fixes:
+- Fix fetch delete bug record
+  ([1425](https://github.com/Shopify/sarama/pull/1425)).
+- Handle SASL/OAUTHBEARER token rejection
+  ([1428](https://github.com/Shopify/sarama/pull/1428)).
+
+#### Version 1.23.0 (2019-07-02)
+
+New Features:
+- Add support for Kafka 2.3.0
+  ([1418](https://github.com/Shopify/sarama/pull/1418)).
+- Add support for ListConsumerGroupOffsets v2
+  ([1374](https://github.com/Shopify/sarama/pull/1374)).
+- Add support for DeleteConsumerGroup
+  ([1417](https://github.com/Shopify/sarama/pull/1417)).
+- Add support for SASLVersion configuration
+  ([1410](https://github.com/Shopify/sarama/pull/1410)).
+- Add kerberos support
+  ([1366](https://github.com/Shopify/sarama/pull/1366)).
+
+Improvements:
+- Improve sasl_scram_client example
+  ([1406](https://github.com/Shopify/sarama/pull/1406)).
+- Fix shutdown and race-condition in consumer-group example
+  ([1404](https://github.com/Shopify/sarama/pull/1404)).
+- Add support for error codes 77—81
+  ([1397](https://github.com/Shopify/sarama/pull/1397)).
+- Pool internal objects allocated per message
+  ([1385](https://github.com/Shopify/sarama/pull/1385)).
+- Reduce packet decoder allocations
+  ([1373](https://github.com/Shopify/sarama/pull/1373)).
+- Support timeout when fetching metadata
+  ([1359](https://github.com/Shopify/sarama/pull/1359)).
+
+Bug Fixes:
+- Fix fetch size integer overflow
+  ([1376](https://github.com/Shopify/sarama/pull/1376)).
+- Handle and log throttled FetchResponses
+  ([1383](https://github.com/Shopify/sarama/pull/1383)).
+- Refactor misspelled word Resouce to Resource
+  ([1368](https://github.com/Shopify/sarama/pull/1368)).
+
+#### Version 1.22.1 (2019-04-29)
+
+Improvements:
+- Use zstd 1.3.8
+  ([1350](https://github.com/Shopify/sarama/pull/1350)).
+- Add support for SaslHandshakeRequest v1
+  ([1354](https://github.com/Shopify/sarama/pull/1354)).
+
+Bug Fixes:
+- Fix V5 MetadataRequest nullable topics array
+  ([1353](https://github.com/Shopify/sarama/pull/1353)).
+- Use a different SCRAM client for each broker connection
+  ([1349](https://github.com/Shopify/sarama/pull/1349)).
+- Fix AllowAutoTopicCreation for MetadataRequest greater than v3
+  ([1344](https://github.com/Shopify/sarama/pull/1344)).
+
+#### Version 1.22.0 (2019-04-09)
+
+New Features:
+- Add Offline Replicas Operation to Client
+  ([1318](https://github.com/Shopify/sarama/pull/1318)).
+- Allow using proxy when connecting to broker
+  ([1326](https://github.com/Shopify/sarama/pull/1326)).
+- Implement ReadCommitted
+  ([1307](https://github.com/Shopify/sarama/pull/1307)).
+- Add support for Kafka 2.2.0
+  ([1331](https://github.com/Shopify/sarama/pull/1331)).
+- Add SASL SCRAM-SHA-512 and SCRAM-SHA-256 mechanismes
+  ([1331](https://github.com/Shopify/sarama/pull/1295)).
+
+Improvements:
+- Unregister all broker metrics on broker stop
+  ([1232](https://github.com/Shopify/sarama/pull/1232)).
+- Add SCRAM authentication example
+  ([1303](https://github.com/Shopify/sarama/pull/1303)).
+- Add consumergroup examples
+  ([1304](https://github.com/Shopify/sarama/pull/1304)).
+- Expose consumer batch size metric
+  ([1296](https://github.com/Shopify/sarama/pull/1296)).
+- Add TLS options to console producer and consumer
+  ([1300](https://github.com/Shopify/sarama/pull/1300)).
+- Reduce client close bookkeeping
+  ([1297](https://github.com/Shopify/sarama/pull/1297)).
+- Satisfy error interface in create responses
+  ([1154](https://github.com/Shopify/sarama/pull/1154)).
+- Please lint gods
+  ([1346](https://github.com/Shopify/sarama/pull/1346)).
+
+Bug Fixes:
+- Fix multi consumer group instance crash
+  ([1338](https://github.com/Shopify/sarama/pull/1338)).
+- Update lz4 to latest version
+  ([1347](https://github.com/Shopify/sarama/pull/1347)).
+- Retry ErrNotCoordinatorForConsumer in new consumergroup session
+  ([1231](https://github.com/Shopify/sarama/pull/1231)).
+- Fix cleanup error handler
+  ([1332](https://github.com/Shopify/sarama/pull/1332)).
+- Fix rate condition in PartitionConsumer
+  ([1156](https://github.com/Shopify/sarama/pull/1156)).
+
+#### Version 1.21.0 (2019-02-24)
+
+New Features:
+- Add CreateAclRequest, DescribeAclRequest, DeleteAclRequest
+  ([1236](https://github.com/Shopify/sarama/pull/1236)).
+- Add DescribeTopic, DescribeConsumerGroup, ListConsumerGroups, ListConsumerGroupOffsets admin requests
+  ([1178](https://github.com/Shopify/sarama/pull/1178)).
+- Implement SASL/OAUTHBEARER
+  ([1240](https://github.com/Shopify/sarama/pull/1240)).
+
+Improvements:
+- Add Go mod support
+  ([1282](https://github.com/Shopify/sarama/pull/1282)).
+- Add error codes 73—76
+  ([1239](https://github.com/Shopify/sarama/pull/1239)).
+- Add retry backoff function
+  ([1160](https://github.com/Shopify/sarama/pull/1160)).
+- Maintain metadata in the producer even when retries are disabled
+  ([1189](https://github.com/Shopify/sarama/pull/1189)).
+- Include ReplicaAssignment in ListTopics
+  ([1274](https://github.com/Shopify/sarama/pull/1274)).
+- Add producer performance tool
+  ([1222](https://github.com/Shopify/sarama/pull/1222)).
+- Add support LogAppend timestamps
+  ([1258](https://github.com/Shopify/sarama/pull/1258)).
+
+Bug Fixes:
+- Fix potential deadlock when a heartbeat request fails
+  ([1286](https://github.com/Shopify/sarama/pull/1286)).
+- Fix consuming compacted topic
+  ([1227](https://github.com/Shopify/sarama/pull/1227)).
+- Set correct Kafka version for DescribeConfigsRequest v1
+  ([1277](https://github.com/Shopify/sarama/pull/1277)).
+- Update kafka test version
+  ([1273](https://github.com/Shopify/sarama/pull/1273)).
+
+#### Version 1.20.1 (2019-01-10)
+
+New Features:
+- Add optional replica id in offset request
+  ([1100](https://github.com/Shopify/sarama/pull/1100)).
+
+Improvements:
+- Implement DescribeConfigs Request + Response v1 & v2
+  ([1230](https://github.com/Shopify/sarama/pull/1230)).
+- Reuse compression objects
+  ([1185](https://github.com/Shopify/sarama/pull/1185)).
+- Switch from png to svg for GoDoc link in README
+  ([1243](https://github.com/Shopify/sarama/pull/1243)).
+- Fix typo in deprecation notice for FetchResponseBlock.Records
+  ([1242](https://github.com/Shopify/sarama/pull/1242)).
+- Fix typos in consumer metadata response file
+  ([1244](https://github.com/Shopify/sarama/pull/1244)).
+
+Bug Fixes:
+- Revert to individual msg retries for non-idempotent
+  ([1203](https://github.com/Shopify/sarama/pull/1203)).
+- Respect MaxMessageBytes limit for uncompressed messages
+  ([1141](https://github.com/Shopify/sarama/pull/1141)).
+
+#### Version 1.20.0 (2018-12-10)
+
+New Features:
+ - Add support for zstd compression
+   ([#1170](https://github.com/Shopify/sarama/pull/1170)).
+ - Add support for Idempotent Producer
+   ([#1152](https://github.com/Shopify/sarama/pull/1152)).
+ - Add support support for Kafka 2.1.0
+   ([#1229](https://github.com/Shopify/sarama/pull/1229)).
+ - Add support support for OffsetCommit request/response pairs versions v1 to v5
+   ([#1201](https://github.com/Shopify/sarama/pull/1201)).
+ - Add support support for OffsetFetch request/response pair up to version v5
+   ([#1198](https://github.com/Shopify/sarama/pull/1198)).
+
+Improvements:
+ - Export broker's Rack setting
+   ([#1173](https://github.com/Shopify/sarama/pull/1173)).
+ - Always use latest patch version of Go on CI
+   ([#1202](https://github.com/Shopify/sarama/pull/1202)).
+ - Add error codes 61 to 72
+   ([#1195](https://github.com/Shopify/sarama/pull/1195)).
+
+Bug Fixes:
+ - Fix build without cgo
+   ([#1182](https://github.com/Shopify/sarama/pull/1182)).
+ - Fix go vet suggestion in consumer group file
+   ([#1209](https://github.com/Shopify/sarama/pull/1209)).
+ - Fix typos in code and comments
+   ([#1228](https://github.com/Shopify/sarama/pull/1228)).
+
+#### Version 1.19.0 (2018-09-27)
+
+New Features:
+ - Implement a higher-level consumer group
+   ([#1099](https://github.com/Shopify/sarama/pull/1099)).
+
+Improvements:
+ - Add support for Go 1.11
+   ([#1176](https://github.com/Shopify/sarama/pull/1176)).
+
+Bug Fixes:
+ - Fix encoding of `MetadataResponse` with version 2 and higher
+   ([#1174](https://github.com/Shopify/sarama/pull/1174)).
+ - Fix race condition in mock async producer
+   ([#1174](https://github.com/Shopify/sarama/pull/1174)).
+
+#### Version 1.18.0 (2018-09-07)
+
+New Features:
+ - Make `Partitioner.RequiresConsistency` vary per-message
+   ([#1112](https://github.com/Shopify/sarama/pull/1112)).
+ - Add customizable partitioner
+   ([#1118](https://github.com/Shopify/sarama/pull/1118)).
+ - Add `ClusterAdmin` support for `CreateTopic`, `DeleteTopic`, `CreatePartitions`,
+   `DeleteRecords`, `DescribeConfig`, `AlterConfig`, `CreateACL`, `ListAcls`, `DeleteACL`
+   ([#1055](https://github.com/Shopify/sarama/pull/1055)).
+
+Improvements:
+ - Add support for Kafka 2.0.0
+   ([#1149](https://github.com/Shopify/sarama/pull/1149)).
+ - Allow setting `LocalAddr` when dialing an address to support multi-homed hosts
+   ([#1123](https://github.com/Shopify/sarama/pull/1123)).
+ - Simpler offset management
+   ([#1127](https://github.com/Shopify/sarama/pull/1127)).
+
+Bug Fixes:
+ - Fix mutation of `ProducerMessage.MetaData` when producing to Kafka
+   ([#1110](https://github.com/Shopify/sarama/pull/1110)).
+ - Fix consumer block when response did not contain all the
+   expected topic/partition blocks
+   ([#1086](https://github.com/Shopify/sarama/pull/1086)).
+ - Fix consumer block when response contains only constrol messages
+   ([#1115](https://github.com/Shopify/sarama/pull/1115)).
+ - Add timeout config for ClusterAdmin requests
+   ([#1142](https://github.com/Shopify/sarama/pull/1142)).
+ - Add version check when producing message with headers
+   ([#1117](https://github.com/Shopify/sarama/pull/1117)).
+ - Fix `MetadataRequest` for empty list of topics
+   ([#1132](https://github.com/Shopify/sarama/pull/1132)).
+ - Fix producer topic metadata on-demand fetch when topic error happens in metadata response
+   ([#1125](https://github.com/Shopify/sarama/pull/1125)).
+
+#### Version 1.17.0 (2018-05-30)
+
+New Features:
+ - Add support for gzip compression levels
+   ([#1044](https://github.com/Shopify/sarama/pull/1044)).
+ - Add support for Metadata request/response pairs versions v1 to v5
+   ([#1047](https://github.com/Shopify/sarama/pull/1047),
+    [#1069](https://github.com/Shopify/sarama/pull/1069)).
+ - Add versioning to JoinGroup request/response pairs
+   ([#1098](https://github.com/Shopify/sarama/pull/1098))
+ - Add support for CreatePartitions, DeleteGroups, DeleteRecords request/response pairs
+   ([#1065](https://github.com/Shopify/sarama/pull/1065),
+    [#1096](https://github.com/Shopify/sarama/pull/1096),
+    [#1027](https://github.com/Shopify/sarama/pull/1027)).
+ - Add `Controller()` method to Client interface
+   ([#1063](https://github.com/Shopify/sarama/pull/1063)).
+
+Improvements:
+ - ConsumerMetadataReq/Resp has been migrated to FindCoordinatorReq/Resp
+   ([#1010](https://github.com/Shopify/sarama/pull/1010)).
+ - Expose missing protocol parts: `msgSet` and `recordBatch`
+   ([#1049](https://github.com/Shopify/sarama/pull/1049)).
+ - Add support for v1 DeleteTopics Request
+   ([#1052](https://github.com/Shopify/sarama/pull/1052)).
+ - Add support for Go 1.10
+   ([#1064](https://github.com/Shopify/sarama/pull/1064)).
+ - Claim support for Kafka 1.1.0
+   ([#1073](https://github.com/Shopify/sarama/pull/1073)).
+
+Bug Fixes:
+ - Fix FindCoordinatorResponse.encode to allow nil Coordinator
+   ([#1050](https://github.com/Shopify/sarama/pull/1050),
+    [#1051](https://github.com/Shopify/sarama/pull/1051)).
+ - Clear all metadata when we have the latest topic info
+   ([#1033](https://github.com/Shopify/sarama/pull/1033)).
+ - Make `PartitionConsumer.Close` idempotent
+   ([#1092](https://github.com/Shopify/sarama/pull/1092)).
+
+#### Version 1.16.0 (2018-02-12)
+
+New Features:
+ - Add support for the Create/Delete Topics request/response pairs
+   ([#1007](https://github.com/Shopify/sarama/pull/1007),
+    [#1008](https://github.com/Shopify/sarama/pull/1008)).
+ - Add support for the Describe/Create/Delete ACL request/response pairs
+   ([#1009](https://github.com/Shopify/sarama/pull/1009)).
+ - Add support for the five transaction-related request/response pairs
+   ([#1016](https://github.com/Shopify/sarama/pull/1016)).
+
+Improvements:
+ - Permit setting version on mock producer responses
+   ([#999](https://github.com/Shopify/sarama/pull/999)).
+ - Add `NewMockBrokerListener` helper for testing TLS connections
+   ([#1019](https://github.com/Shopify/sarama/pull/1019)).
+ - Changed the default value for `Consumer.Fetch.Default` from 32KiB to 1MiB
+   which results in much higher throughput in most cases
+   ([#1024](https://github.com/Shopify/sarama/pull/1024)).
+ - Reuse the `time.Ticker` across fetch requests in the PartitionConsumer to
+   reduce CPU and memory usage when processing many partitions
+   ([#1028](https://github.com/Shopify/sarama/pull/1028)).
+ - Assign relative offsets to messages in the producer to save the brokers a
+   recompression pass
+   ([#1002](https://github.com/Shopify/sarama/pull/1002),
+    [#1015](https://github.com/Shopify/sarama/pull/1015)).
+
+Bug Fixes:
+ - Fix producing uncompressed batches with the new protocol format
+   ([#1032](https://github.com/Shopify/sarama/issues/1032)).
+ - Fix consuming compacted topics with the new protocol format
+   ([#1005](https://github.com/Shopify/sarama/issues/1005)).
+ - Fix consuming topics with a mix of protocol formats
+   ([#1021](https://github.com/Shopify/sarama/issues/1021)).
+ - Fix consuming when the broker includes multiple batches in a single response
+   ([#1022](https://github.com/Shopify/sarama/issues/1022)).
+ - Fix detection of `PartialTrailingMessage` when the partial message was
+   truncated before the magic value indicating its version
+   ([#1030](https://github.com/Shopify/sarama/pull/1030)).
+ - Fix expectation-checking in the mock of `SyncProducer.SendMessages`
+   ([#1035](https://github.com/Shopify/sarama/pull/1035)).
+
+#### Version 1.15.0 (2017-12-08)
+
+New Features:
+ - Claim official support for Kafka 1.0, though it did already work
+   ([#984](https://github.com/Shopify/sarama/pull/984)).
+ - Helper methods for Kafka version numbers to/from strings
+   ([#989](https://github.com/Shopify/sarama/pull/989)).
+ - Implement CreatePartitions request/response
+   ([#985](https://github.com/Shopify/sarama/pull/985)).
+
+Improvements:
+ - Add error codes 45-60
+   ([#986](https://github.com/Shopify/sarama/issues/986)).
+
+Bug Fixes:
+ - Fix slow consuming for certain Kafka 0.11/1.0 configurations
+   ([#982](https://github.com/Shopify/sarama/pull/982)).
+ - Correctly determine when a FetchResponse contains the new message format
+   ([#990](https://github.com/Shopify/sarama/pull/990)).
+ - Fix producing with multiple headers
+   ([#996](https://github.com/Shopify/sarama/pull/996)).
+ - Fix handling of truncated record batches
+   ([#998](https://github.com/Shopify/sarama/pull/998)).
+ - Fix leaking metrics when closing brokers
+   ([#991](https://github.com/Shopify/sarama/pull/991)).
+
+#### Version 1.14.0 (2017-11-13)
+
+New Features:
+ - Add support for the new Kafka 0.11 record-batch format, including the wire
+   protocol and the necessary behavioural changes in the producer and consumer.
+   Transactions and idempotency are not yet supported, but producing and
+   consuming should work with all the existing bells and whistles (batching,
+   compression, etc) as well as the new custom headers. Thanks to Vlad Hanciuta
+   of Arista Networks for this work. Part of
+   ([#901](https://github.com/Shopify/sarama/issues/901)).
+
+Bug Fixes:
+ - Fix encoding of ProduceResponse versions in test
+   ([#970](https://github.com/Shopify/sarama/pull/970)).
+ - Return partial replicas list when we have it
+   ([#975](https://github.com/Shopify/sarama/pull/975)).
+
+#### Version 1.13.0 (2017-10-04)
+
+New Features:
+ - Support for FetchRequest version 3
+   ([#905](https://github.com/Shopify/sarama/pull/905)).
+ - Permit setting version on mock FetchResponses
+   ([#939](https://github.com/Shopify/sarama/pull/939)).
+ - Add a configuration option to support storing only minimal metadata for
+   extremely large clusters
+   ([#937](https://github.com/Shopify/sarama/pull/937)).
+ - Add `PartitionOffsetManager.ResetOffset` for backtracking tracked offsets
+   ([#932](https://github.com/Shopify/sarama/pull/932)).
+
+Improvements:
+ - Provide the block-level timestamp when consuming compressed messages
+   ([#885](https://github.com/Shopify/sarama/issues/885)).
+ - `Client.Replicas` and `Client.InSyncReplicas` now respect the order returned
+   by the broker, which can be meaningful
+   ([#930](https://github.com/Shopify/sarama/pull/930)).
+ - Use a `Ticker` to reduce consumer timer overhead at the cost of higher
+   variance in the actual timeout
+   ([#933](https://github.com/Shopify/sarama/pull/933)).
+
+Bug Fixes:
+ - Gracefully handle messages with negative timestamps
+   ([#907](https://github.com/Shopify/sarama/pull/907)).
+ - Raise a proper error when encountering an unknown message version
+   ([#940](https://github.com/Shopify/sarama/pull/940)).
+
+#### Version 1.12.0 (2017-05-08)
+
+New Features:
+ - Added support for the `ApiVersions` request and response pair, and Kafka
+   version 0.10.2 ([#867](https://github.com/Shopify/sarama/pull/867)). Note
+   that you still need to specify the Kafka version in the Sarama configuration
+   for the time being.
+ - Added a `Brokers` method to the Client which returns the complete set of
+   active brokers ([#813](https://github.com/Shopify/sarama/pull/813)).
+ - Added an `InSyncReplicas` method to the Client which returns the set of all
+   in-sync broker IDs for the given partition, now that the Kafka versions for
+   which this was misleading are no longer in our supported set
+   ([#872](https://github.com/Shopify/sarama/pull/872)).
+ - Added a `NewCustomHashPartitioner` method which allows constructing a hash
+   partitioner with a custom hash method in case the default (FNV-1a) is not
+   suitable
+   ([#837](https://github.com/Shopify/sarama/pull/837),
+    [#841](https://github.com/Shopify/sarama/pull/841)).
+
+Improvements:
+ - Recognize more Kafka error codes
+   ([#859](https://github.com/Shopify/sarama/pull/859)).
+
+Bug Fixes:
+ - Fix an issue where decoding a malformed FetchRequest would not return the
+   correct error ([#818](https://github.com/Shopify/sarama/pull/818)).
+ - Respect ordering of group protocols in JoinGroupRequests. This fix is
+   transparent if you're using the `AddGroupProtocol` or
+   `AddGroupProtocolMetadata` helpers; otherwise you will need to switch from
+   the `GroupProtocols` field (now deprecated) to use `OrderedGroupProtocols`
+   ([#812](https://github.com/Shopify/sarama/issues/812)).
+ - Fix an alignment-related issue with atomics on 32-bit architectures
+   ([#859](https://github.com/Shopify/sarama/pull/859)).
+
+#### Version 1.11.0 (2016-12-20)
+
+_Important:_ As of Sarama 1.11 it is necessary to set the config value of
+`Producer.Return.Successes` to true in order to use the SyncProducer. Previous
+versions would silently override this value when instantiating a SyncProducer
+which led to unexpected values and data races.
+
+New Features:
+ - Metrics! Thanks to Sébastien Launay for all his work on this feature
+   ([#701](https://github.com/Shopify/sarama/pull/701),
+    [#746](https://github.com/Shopify/sarama/pull/746),
+    [#766](https://github.com/Shopify/sarama/pull/766)).
+ - Add support for LZ4 compression
+   ([#786](https://github.com/Shopify/sarama/pull/786)).
+ - Add support for ListOffsetRequest v1 and Kafka 0.10.1
+   ([#775](https://github.com/Shopify/sarama/pull/775)).
+ - Added a `HighWaterMarks` method to the Consumer which aggregates the
+   `HighWaterMarkOffset` values of its child topic/partitions
+   ([#769](https://github.com/Shopify/sarama/pull/769)).
+
+Bug Fixes:
+ - Fixed producing when using timestamps, compression and Kafka 0.10
+   ([#759](https://github.com/Shopify/sarama/pull/759)).
+ - Added missing decoder methods to DescribeGroups response
+   ([#756](https://github.com/Shopify/sarama/pull/756)).
+ - Fix producer shutdown when `Return.Errors` is disabled
+   ([#787](https://github.com/Shopify/sarama/pull/787)).
+ - Don't mutate configuration in SyncProducer
+   ([#790](https://github.com/Shopify/sarama/pull/790)).
+ - Fix crash on SASL initialization failure
+   ([#795](https://github.com/Shopify/sarama/pull/795)).
+
+#### Version 1.10.1 (2016-08-30)
+
+Bug Fixes:
+ - Fix the documentation for `HashPartitioner` which was incorrect
+   ([#717](https://github.com/Shopify/sarama/pull/717)).
+ - Permit client creation even when it is limited by ACLs
+   ([#722](https://github.com/Shopify/sarama/pull/722)).
+ - Several fixes to the consumer timer optimization code, regressions introduced
+   in v1.10.0. Go's timers are finicky
+   ([#730](https://github.com/Shopify/sarama/pull/730),
+    [#733](https://github.com/Shopify/sarama/pull/733),
+    [#734](https://github.com/Shopify/sarama/pull/734)).
+ - Handle consuming compressed relative offsets with Kafka 0.10
+   ([#735](https://github.com/Shopify/sarama/pull/735)).
+
+#### Version 1.10.0 (2016-08-02)
+
+_Important:_ As of Sarama 1.10 it is necessary to tell Sarama the version of
+Kafka you are running against (via the `config.Version` value) in order to use
+features that may not be compatible with old Kafka versions. If you don't
+specify this value it will default to 0.8.2 (the minimum supported), and trying
+to use more recent features (like the offset manager) will fail with an error.
+
+_Also:_ The offset-manager's behaviour has been changed to match the upstream
+java consumer (see [#705](https://github.com/Shopify/sarama/pull/705) and
+[#713](https://github.com/Shopify/sarama/pull/713)). If you use the
+offset-manager, please ensure that you are committing one *greater* than the
+last consumed message offset or else you may end up consuming duplicate
+messages.
+
+New Features:
+ - Support for Kafka 0.10
+   ([#672](https://github.com/Shopify/sarama/pull/672),
+    [#678](https://github.com/Shopify/sarama/pull/678),
+    [#681](https://github.com/Shopify/sarama/pull/681), and others).
+ - Support for configuring the target Kafka version
+   ([#676](https://github.com/Shopify/sarama/pull/676)).
+ - Batch producing support in the SyncProducer
+   ([#677](https://github.com/Shopify/sarama/pull/677)).
+ - Extend producer mock to allow setting expectations on message contents
+   ([#667](https://github.com/Shopify/sarama/pull/667)).
+
+Improvements:
+ - Support `nil` compressed messages for deleting in compacted topics
+   ([#634](https://github.com/Shopify/sarama/pull/634)).
+ - Pre-allocate decoding errors, greatly reducing heap usage and GC time against
+   misbehaving brokers ([#690](https://github.com/Shopify/sarama/pull/690)).
+ - Re-use consumer expiry timers, removing one allocation per consumed message
+   ([#707](https://github.com/Shopify/sarama/pull/707)).
+
+Bug Fixes:
+ - Actually default the client ID to "sarama" like we say we do
+   ([#664](https://github.com/Shopify/sarama/pull/664)).
+ - Fix a rare issue where `Client.Leader` could return the wrong error
+   ([#685](https://github.com/Shopify/sarama/pull/685)).
+ - Fix a possible tight loop in the consumer
+   ([#693](https://github.com/Shopify/sarama/pull/693)).
+ - Match upstream's offset-tracking behaviour
+   ([#705](https://github.com/Shopify/sarama/pull/705)).
+ - Report UnknownTopicOrPartition errors from the offset manager
+   ([#706](https://github.com/Shopify/sarama/pull/706)).
+ - Fix possible negative partition value from the HashPartitioner
+   ([#709](https://github.com/Shopify/sarama/pull/709)).
+
+#### Version 1.9.0 (2016-05-16)
+
+New Features:
+ - Add support for custom offset manager retention durations
+   ([#602](https://github.com/Shopify/sarama/pull/602)).
+ - Publish low-level mocks to enable testing of third-party producer/consumer
+   implementations ([#570](https://github.com/Shopify/sarama/pull/570)).
+ - Declare support for Golang 1.6
+   ([#611](https://github.com/Shopify/sarama/pull/611)).
+ - Support for SASL plain-text auth
+   ([#648](https://github.com/Shopify/sarama/pull/648)).
+
+Improvements:
+ - Simplified broker locking scheme slightly
+   ([#604](https://github.com/Shopify/sarama/pull/604)).
+ - Documentation cleanup
+   ([#605](https://github.com/Shopify/sarama/pull/605),
+    [#621](https://github.com/Shopify/sarama/pull/621),
+    [#654](https://github.com/Shopify/sarama/pull/654)).
+
+Bug Fixes:
+ - Fix race condition shutting down the OffsetManager
+   ([#658](https://github.com/Shopify/sarama/pull/658)).
+
+#### Version 1.8.0 (2016-02-01)
+
+New Features:
+ - Full support for Kafka 0.9:
+   - All protocol messages and fields
+   ([#586](https://github.com/Shopify/sarama/pull/586),
+   [#588](https://github.com/Shopify/sarama/pull/588),
+   [#590](https://github.com/Shopify/sarama/pull/590)).
+   - Verified that TLS support works
+   ([#581](https://github.com/Shopify/sarama/pull/581)).
+   - Fixed the OffsetManager compatibility
+   ([#585](https://github.com/Shopify/sarama/pull/585)).
+
+Improvements:
+ - Optimize for fewer system calls when reading from the network
+   ([#584](https://github.com/Shopify/sarama/pull/584)).
+ - Automatically retry `InvalidMessage` errors to match upstream behaviour
+   ([#589](https://github.com/Shopify/sarama/pull/589)).
+
+#### Version 1.7.0 (2015-12-11)
+
+New Features:
+ - Preliminary support for Kafka 0.9
+   ([#572](https://github.com/Shopify/sarama/pull/572)). This comes with several
+   caveats:
+   - Protocol-layer support is mostly in place
+     ([#577](https://github.com/Shopify/sarama/pull/577)), however Kafka 0.9
+     renamed some messages and fields, which we did not in order to preserve API
+     compatibility.
+   - The producer and consumer work against 0.9, but the offset manager does
+     not ([#573](https://github.com/Shopify/sarama/pull/573)).
+   - TLS support may or may not work
+     ([#581](https://github.com/Shopify/sarama/pull/581)).
+
+Improvements:
+ - Don't wait for request timeouts on dead brokers, greatly speeding recovery
+   when the TCP connection is left hanging
+   ([#548](https://github.com/Shopify/sarama/pull/548)).
+ - Refactored part of the producer. The new version provides a much more elegant
+   solution to [#449](https://github.com/Shopify/sarama/pull/449). It is also
+   slightly more efficient, and much more precise in calculating batch sizes
+   when compression is used
+   ([#549](https://github.com/Shopify/sarama/pull/549),
+   [#550](https://github.com/Shopify/sarama/pull/550),
+   [#551](https://github.com/Shopify/sarama/pull/551)).
+
+Bug Fixes:
+ - Fix race condition in consumer test mock
+   ([#553](https://github.com/Shopify/sarama/pull/553)).
+
+#### Version 1.6.1 (2015-09-25)
+
+Bug Fixes:
+ - Fix panic that could occur if a user-supplied message value failed to encode
+   ([#449](https://github.com/Shopify/sarama/pull/449)).
+
+#### Version 1.6.0 (2015-09-04)
+
+New Features:
+ - Implementation of a consumer offset manager using the APIs introduced in
+   Kafka 0.8.2. The API is designed mainly for integration into a future
+   high-level consumer, not for direct use, although it is *possible* to use it
+   directly.
+   ([#461](https://github.com/Shopify/sarama/pull/461)).
+
+Improvements:
+ - CRC32 calculation is much faster on machines with SSE4.2 instructions,
+   removing a major hotspot from most profiles
+   ([#255](https://github.com/Shopify/sarama/pull/255)).
+
+Bug Fixes:
+ - Make protocol decoding more robust against some malformed packets generated
+   by go-fuzz ([#523](https://github.com/Shopify/sarama/pull/523),
+   [#525](https://github.com/Shopify/sarama/pull/525)) or found in other ways
+   ([#528](https://github.com/Shopify/sarama/pull/528)).
+ - Fix a potential race condition panic in the consumer on shutdown
+   ([#529](https://github.com/Shopify/sarama/pull/529)).
+
+#### Version 1.5.0 (2015-08-17)
+
+New Features:
+ - TLS-encrypted network connections are now supported. This feature is subject
+   to change when Kafka releases built-in TLS support, but for now this is
+   enough to work with TLS-terminating proxies
+   ([#154](https://github.com/Shopify/sarama/pull/154)).
+
+Improvements:
+ - The consumer will not block if a single partition is not drained by the user;
+   all other partitions will continue to consume normally
+   ([#485](https://github.com/Shopify/sarama/pull/485)).
+ - Formatting of error strings has been much improved
+   ([#495](https://github.com/Shopify/sarama/pull/495)).
+ - Internal refactoring of the producer for code cleanliness and to enable
+   future work ([#300](https://github.com/Shopify/sarama/pull/300)).
+
+Bug Fixes:
+ - Fix a potential deadlock in the consumer on shutdown
+   ([#475](https://github.com/Shopify/sarama/pull/475)).
+
+#### Version 1.4.3 (2015-07-21)
+
+Bug Fixes:
+ - Don't include the partitioner in the producer's "fetch partitions"
+   circuit-breaker ([#466](https://github.com/Shopify/sarama/pull/466)).
+ - Don't retry messages until the broker is closed when abandoning a broker in
+   the producer ([#468](https://github.com/Shopify/sarama/pull/468)).
+ - Update the import path for snappy-go, it has moved again and the API has
+   changed slightly ([#486](https://github.com/Shopify/sarama/pull/486)).
+
+#### Version 1.4.2 (2015-05-27)
+
+Bug Fixes:
+ - Update the import path for snappy-go, it has moved from google code to github
+   ([#456](https://github.com/Shopify/sarama/pull/456)).
+
+#### Version 1.4.1 (2015-05-25)
+
+Improvements:
+ - Optimizations when decoding snappy messages, thanks to John Potocny
+   ([#446](https://github.com/Shopify/sarama/pull/446)).
+
+Bug Fixes:
+ - Fix hypothetical race conditions on producer shutdown
+   ([#450](https://github.com/Shopify/sarama/pull/450),
+   [#451](https://github.com/Shopify/sarama/pull/451)).
+
+#### Version 1.4.0 (2015-05-01)
+
+New Features:
+ - The consumer now implements `Topics()` and `Partitions()` methods to enable
+   users to dynamically choose what topics/partitions to consume without
+   instantiating a full client
+   ([#431](https://github.com/Shopify/sarama/pull/431)).
+ - The partition-consumer now exposes the high water mark offset value returned
+   by the broker via the `HighWaterMarkOffset()` method ([#339](https://github.com/Shopify/sarama/pull/339)).
+ - Added a `kafka-console-consumer` tool capable of handling multiple
+   partitions, and deprecated the now-obsolete `kafka-console-partitionConsumer`
+   ([#439](https://github.com/Shopify/sarama/pull/439),
+   [#442](https://github.com/Shopify/sarama/pull/442)).
+
+Improvements:
+ - The producer's logging during retry scenarios is more consistent, more
+   useful, and slightly less verbose
+   ([#429](https://github.com/Shopify/sarama/pull/429)).
+ - The client now shuffles its initial list of seed brokers in order to prevent
+   thundering herd on the first broker in the list
+   ([#441](https://github.com/Shopify/sarama/pull/441)).
+
+Bug Fixes:
+ - The producer now correctly manages its state if retries occur when it is
+   shutting down, fixing several instances of confusing behaviour and at least
+   one potential deadlock ([#419](https://github.com/Shopify/sarama/pull/419)).
+ - The consumer now handles messages for different partitions asynchronously,
+   making it much more resilient to specific user code ordering
+   ([#325](https://github.com/Shopify/sarama/pull/325)).
+
+#### Version 1.3.0 (2015-04-16)
+
+New Features:
+ - The client now tracks consumer group coordinators using
+   ConsumerMetadataRequests similar to how it tracks partition leadership using
+   regular MetadataRequests ([#411](https://github.com/Shopify/sarama/pull/411)).
+   This adds two methods to the client API:
+   - `Coordinator(consumerGroup string) (*Broker, error)`
+   - `RefreshCoordinator(consumerGroup string) error`
+
+Improvements:
+ - ConsumerMetadataResponses now automatically create a Broker object out of the
+   ID/address/port combination for the Coordinator; accessing the fields
+   individually has been deprecated
+   ([#413](https://github.com/Shopify/sarama/pull/413)).
+ - Much improved handling of `OffsetOutOfRange` errors in the consumer.
+   Consumers will fail to start if the provided offset is out of range
+   ([#418](https://github.com/Shopify/sarama/pull/418))
+   and they will automatically shut down if the offset falls out of range
+   ([#424](https://github.com/Shopify/sarama/pull/424)).
+ - Small performance improvement in encoding and decoding protocol messages
+   ([#427](https://github.com/Shopify/sarama/pull/427)).
+
+Bug Fixes:
+ - Fix a rare race condition in the client's background metadata refresher if
+   it happens to be activated while the client is being closed
+   ([#422](https://github.com/Shopify/sarama/pull/422)).
+
+#### Version 1.2.0 (2015-04-07)
+
+Improvements:
+ - The producer's behaviour when `Flush.Frequency` is set is now more intuitive
+   ([#389](https://github.com/Shopify/sarama/pull/389)).
+ - The producer is now somewhat more memory-efficient during and after retrying
+   messages due to an improved queue implementation
+   ([#396](https://github.com/Shopify/sarama/pull/396)).
+ - The consumer produces much more useful logging output when leadership
+   changes ([#385](https://github.com/Shopify/sarama/pull/385)).
+ - The client's `GetOffset` method will now automatically refresh metadata and
+   retry once in the event of stale information or similar
+   ([#394](https://github.com/Shopify/sarama/pull/394)).
+ - Broker connections now have support for using TCP keepalives
+   ([#407](https://github.com/Shopify/sarama/issues/407)).
+
+Bug Fixes:
+ - The OffsetCommitRequest message now correctly implements all three possible
+   API versions ([#390](https://github.com/Shopify/sarama/pull/390),
+   [#400](https://github.com/Shopify/sarama/pull/400)).
+
+#### Version 1.1.0 (2015-03-20)
+
+Improvements:
+ - Wrap the producer's partitioner call in a circuit-breaker so that repeatedly
+   broken topics don't choke throughput
+   ([#373](https://github.com/Shopify/sarama/pull/373)).
+
+Bug Fixes:
+ - Fix the producer's internal reference counting in certain unusual scenarios
+   ([#367](https://github.com/Shopify/sarama/pull/367)).
+ - Fix the consumer's internal reference counting in certain unusual scenarios
+   ([#369](https://github.com/Shopify/sarama/pull/369)).
+ - Fix a condition where the producer's internal control messages could have
+   gotten stuck ([#368](https://github.com/Shopify/sarama/pull/368)).
+ - Fix an issue where invalid partition lists would be cached when asking for
+   metadata for a non-existant topic ([#372](https://github.com/Shopify/sarama/pull/372)).
+
+
+#### Version 1.0.0 (2015-03-17)
+
+Version 1.0.0 is the first tagged version, and is almost a complete rewrite. The primary differences with previous untagged versions are:
+
+- The producer has been rewritten; there is now a `SyncProducer` with a blocking API, and an `AsyncProducer` that is non-blocking.
+- The consumer has been rewritten to only open one connection per broker instead of one connection per partition.
+- The main types of Sarama are now interfaces to make depedency injection easy; mock implementations for `Consumer`, `SyncProducer` and `AsyncProducer` are provided in the `github.com/Shopify/sarama/mocks` package.
+- For most uses cases, it is no longer necessary to open a `Client`; this will be done for you.
+- All the configuration values have been unified in the `Config` struct.
+- Much improved test suite.
diff --git a/vendor/github.com/Shopify/sarama/LICENSE b/vendor/github.com/Shopify/sarama/LICENSE
new file mode 100644
index 0000000..d2bf435
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/LICENSE
@@ -0,0 +1,20 @@
+Copyright (c) 2013 Shopify
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/vendor/github.com/Shopify/sarama/Makefile b/vendor/github.com/Shopify/sarama/Makefile
new file mode 100644
index 0000000..9c8329e
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/Makefile
@@ -0,0 +1,56 @@
+export GO111MODULE=on
+
+default: fmt vet errcheck test lint
+
+# Taken from https://github.com/codecov/example-go#caveat-multiple-files
+.PHONY: test
+test:
+	echo "mode: atomic" > coverage.txt
+	for d in `go list ./...`; do \
+		go test -p 1 -v -timeout 6m -race -coverprofile=profile.out -covermode=atomic $$d || exit 1; \
+		if [ -f profile.out ]; then \
+			tail +2 profile.out >> coverage.txt; \
+			rm profile.out; \
+		fi \
+	done
+
+GOLINT := $(shell command -v golint)
+
+.PHONY: lint
+lint:
+ifndef GOLINT
+	go get golang.org/x/lint/golint
+endif
+	go list ./... | xargs golint
+
+.PHONY: vet
+vet:
+	go vet ./...
+
+ERRCHECK := $(shell command -v errcheck)
+# See https://github.com/kisielk/errcheck/pull/141 for details on ignorepkg
+.PHONY: errcheck
+errcheck:
+ifndef ERRCHECK
+	go get github.com/kisielk/errcheck
+endif
+	errcheck -ignorepkg fmt github.com/Shopify/sarama/...
+
+.PHONY: fmt
+fmt:
+	@if [ -n "$$(go fmt ./...)" ]; then echo 'Please run go fmt on your code.' && exit 1; fi
+
+.PHONY : install_dependencies
+install_dependencies: get
+
+.PHONY: get
+get:
+	go get -v ./...
+
+.PHONY: clean
+clean:
+	go clean ./...
+
+.PHONY: tidy
+tidy:
+	go mod tidy -v
diff --git a/vendor/github.com/Shopify/sarama/README.md b/vendor/github.com/Shopify/sarama/README.md
new file mode 100644
index 0000000..18ad7bf
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/README.md
@@ -0,0 +1,36 @@
+# sarama
+
+[![GoDoc](https://godoc.org/github.com/Shopify/sarama?status.svg)](https://godoc.org/github.com/Shopify/sarama)
+[![Build Status](https://travis-ci.org/Shopify/sarama.svg?branch=master)](https://travis-ci.org/Shopify/sarama)
+[![Coverage](https://codecov.io/gh/Shopify/sarama/branch/master/graph/badge.svg)](https://codecov.io/gh/Shopify/sarama)
+
+Sarama is an MIT-licensed Go client library for [Apache Kafka](https://kafka.apache.org/) version 0.8 (and later).
+
+## Getting started
+
+- API documentation and examples are available via [godoc](https://godoc.org/github.com/Shopify/sarama).
+- Mocks for testing are available in the [mocks](./mocks) subpackage.
+- The [examples](./examples) directory contains more elaborate example applications.
+- The [tools](./tools) directory contains command line tools that can be useful for testing, diagnostics, and instrumentation.
+
+You might also want to look at the [Frequently Asked Questions](https://github.com/Shopify/sarama/wiki/Frequently-Asked-Questions).
+
+## Compatibility and API stability
+
+Sarama provides a "2 releases + 2 months" compatibility guarantee: we support
+the two latest stable releases of Kafka and Go, and we provide a two month
+grace period for older releases. This means we currently officially support
+Go 1.12 through 1.13, and Kafka 2.1 through 2.4, although older releases are
+still likely to work.
+
+Sarama follows semantic versioning and provides API stability via the gopkg.in service.
+You can import a version with a guaranteed stable API via http://gopkg.in/Shopify/sarama.v1.
+A changelog is available [here](CHANGELOG.md).
+
+## Contributing
+
+- Get started by checking our [contribution guidelines](https://github.com/Shopify/sarama/blob/master/.github/CONTRIBUTING.md).
+- Read the [Sarama wiki](https://github.com/Shopify/sarama/wiki) for more technical and design details.
+- The [Kafka Protocol Specification](https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol) contains a wealth of useful information.
+- For more general issues, there is [a google group](https://groups.google.com/forum/#!forum/kafka-clients) for Kafka client developers.
+- If you have any questions, just ask!
diff --git a/vendor/github.com/Shopify/sarama/Vagrantfile b/vendor/github.com/Shopify/sarama/Vagrantfile
new file mode 100644
index 0000000..f4b848a
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/Vagrantfile
@@ -0,0 +1,20 @@
+# -*- mode: ruby -*-
+# vi: set ft=ruby :
+
+# Vagrantfile API/syntax version. Don't touch unless you know what you're doing!
+VAGRANTFILE_API_VERSION = "2"
+
+# We have 5 * 192MB ZK processes and 5 * 320MB Kafka processes => 2560MB
+MEMORY = 3072
+
+Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
+  config.vm.box = "ubuntu/trusty64"
+
+  config.vm.provision :shell, path: "vagrant/provision.sh"
+
+  config.vm.network "private_network", ip: "192.168.100.67"
+
+  config.vm.provider "virtualbox" do |v|
+    v.memory = MEMORY
+  end
+end
diff --git a/vendor/github.com/Shopify/sarama/acl_bindings.go b/vendor/github.com/Shopify/sarama/acl_bindings.go
new file mode 100644
index 0000000..50b689d
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/acl_bindings.go
@@ -0,0 +1,138 @@
+package sarama
+
+//Resource holds information about acl resource type
+type Resource struct {
+	ResourceType        AclResourceType
+	ResourceName        string
+	ResourcePatternType AclResourcePatternType
+}
+
+func (r *Resource) encode(pe packetEncoder, version int16) error {
+	pe.putInt8(int8(r.ResourceType))
+
+	if err := pe.putString(r.ResourceName); err != nil {
+		return err
+	}
+
+	if version == 1 {
+		if r.ResourcePatternType == AclPatternUnknown {
+			Logger.Print("Cannot encode an unknown resource pattern type, using Literal instead")
+			r.ResourcePatternType = AclPatternLiteral
+		}
+		pe.putInt8(int8(r.ResourcePatternType))
+	}
+
+	return nil
+}
+
+func (r *Resource) decode(pd packetDecoder, version int16) (err error) {
+	resourceType, err := pd.getInt8()
+	if err != nil {
+		return err
+	}
+	r.ResourceType = AclResourceType(resourceType)
+
+	if r.ResourceName, err = pd.getString(); err != nil {
+		return err
+	}
+	if version == 1 {
+		pattern, err := pd.getInt8()
+		if err != nil {
+			return err
+		}
+		r.ResourcePatternType = AclResourcePatternType(pattern)
+	}
+
+	return nil
+}
+
+//Acl holds information about acl type
+type Acl struct {
+	Principal      string
+	Host           string
+	Operation      AclOperation
+	PermissionType AclPermissionType
+}
+
+func (a *Acl) encode(pe packetEncoder) error {
+	if err := pe.putString(a.Principal); err != nil {
+		return err
+	}
+
+	if err := pe.putString(a.Host); err != nil {
+		return err
+	}
+
+	pe.putInt8(int8(a.Operation))
+	pe.putInt8(int8(a.PermissionType))
+
+	return nil
+}
+
+func (a *Acl) decode(pd packetDecoder, version int16) (err error) {
+	if a.Principal, err = pd.getString(); err != nil {
+		return err
+	}
+
+	if a.Host, err = pd.getString(); err != nil {
+		return err
+	}
+
+	operation, err := pd.getInt8()
+	if err != nil {
+		return err
+	}
+	a.Operation = AclOperation(operation)
+
+	permissionType, err := pd.getInt8()
+	if err != nil {
+		return err
+	}
+	a.PermissionType = AclPermissionType(permissionType)
+
+	return nil
+}
+
+//ResourceAcls is an acl resource type
+type ResourceAcls struct {
+	Resource
+	Acls []*Acl
+}
+
+func (r *ResourceAcls) encode(pe packetEncoder, version int16) error {
+	if err := r.Resource.encode(pe, version); err != nil {
+		return err
+	}
+
+	if err := pe.putArrayLength(len(r.Acls)); err != nil {
+		return err
+	}
+	for _, acl := range r.Acls {
+		if err := acl.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *ResourceAcls) decode(pd packetDecoder, version int16) error {
+	if err := r.Resource.decode(pd, version); err != nil {
+		return err
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Acls = make([]*Acl, n)
+	for i := 0; i < n; i++ {
+		r.Acls[i] = new(Acl)
+		if err := r.Acls[i].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/acl_create_request.go b/vendor/github.com/Shopify/sarama/acl_create_request.go
new file mode 100644
index 0000000..da1cdef
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/acl_create_request.go
@@ -0,0 +1,85 @@
+package sarama
+
+//CreateAclsRequest is an acl creation request
+type CreateAclsRequest struct {
+	Version      int16
+	AclCreations []*AclCreation
+}
+
+func (c *CreateAclsRequest) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(c.AclCreations)); err != nil {
+		return err
+	}
+
+	for _, aclCreation := range c.AclCreations {
+		if err := aclCreation.encode(pe, c.Version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *CreateAclsRequest) decode(pd packetDecoder, version int16) (err error) {
+	c.Version = version
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	c.AclCreations = make([]*AclCreation, n)
+
+	for i := 0; i < n; i++ {
+		c.AclCreations[i] = new(AclCreation)
+		if err := c.AclCreations[i].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *CreateAclsRequest) key() int16 {
+	return 30
+}
+
+func (c *CreateAclsRequest) version() int16 {
+	return c.Version
+}
+
+func (c *CreateAclsRequest) requiredVersion() KafkaVersion {
+	switch c.Version {
+	case 1:
+		return V2_0_0_0
+	default:
+		return V0_11_0_0
+	}
+}
+
+//AclCreation is a wrapper around Resource and Acl type
+type AclCreation struct {
+	Resource
+	Acl
+}
+
+func (a *AclCreation) encode(pe packetEncoder, version int16) error {
+	if err := a.Resource.encode(pe, version); err != nil {
+		return err
+	}
+	if err := a.Acl.encode(pe); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (a *AclCreation) decode(pd packetDecoder, version int16) (err error) {
+	if err := a.Resource.decode(pd, version); err != nil {
+		return err
+	}
+	if err := a.Acl.decode(pd, version); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/acl_create_response.go b/vendor/github.com/Shopify/sarama/acl_create_response.go
new file mode 100644
index 0000000..f5a5e9a
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/acl_create_response.go
@@ -0,0 +1,90 @@
+package sarama
+
+import "time"
+
+//CreateAclsResponse is a an acl reponse creation type
+type CreateAclsResponse struct {
+	ThrottleTime         time.Duration
+	AclCreationResponses []*AclCreationResponse
+}
+
+func (c *CreateAclsResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(c.ThrottleTime / time.Millisecond))
+
+	if err := pe.putArrayLength(len(c.AclCreationResponses)); err != nil {
+		return err
+	}
+
+	for _, aclCreationResponse := range c.AclCreationResponses {
+		if err := aclCreationResponse.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *CreateAclsResponse) decode(pd packetDecoder, version int16) (err error) {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	c.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	c.AclCreationResponses = make([]*AclCreationResponse, n)
+	for i := 0; i < n; i++ {
+		c.AclCreationResponses[i] = new(AclCreationResponse)
+		if err := c.AclCreationResponses[i].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *CreateAclsResponse) key() int16 {
+	return 30
+}
+
+func (c *CreateAclsResponse) version() int16 {
+	return 0
+}
+
+func (c *CreateAclsResponse) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
+
+//AclCreationResponse is an acl creation response type
+type AclCreationResponse struct {
+	Err    KError
+	ErrMsg *string
+}
+
+func (a *AclCreationResponse) encode(pe packetEncoder) error {
+	pe.putInt16(int16(a.Err))
+
+	if err := pe.putNullableString(a.ErrMsg); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (a *AclCreationResponse) decode(pd packetDecoder, version int16) (err error) {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	a.Err = KError(kerr)
+
+	if a.ErrMsg, err = pd.getNullableString(); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/acl_delete_request.go b/vendor/github.com/Shopify/sarama/acl_delete_request.go
new file mode 100644
index 0000000..15908ea
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/acl_delete_request.go
@@ -0,0 +1,58 @@
+package sarama
+
+//DeleteAclsRequest is a delete acl request
+type DeleteAclsRequest struct {
+	Version int
+	Filters []*AclFilter
+}
+
+func (d *DeleteAclsRequest) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(d.Filters)); err != nil {
+		return err
+	}
+
+	for _, filter := range d.Filters {
+		filter.Version = d.Version
+		if err := filter.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (d *DeleteAclsRequest) decode(pd packetDecoder, version int16) (err error) {
+	d.Version = int(version)
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	d.Filters = make([]*AclFilter, n)
+	for i := 0; i < n; i++ {
+		d.Filters[i] = new(AclFilter)
+		d.Filters[i].Version = int(version)
+		if err := d.Filters[i].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (d *DeleteAclsRequest) key() int16 {
+	return 31
+}
+
+func (d *DeleteAclsRequest) version() int16 {
+	return int16(d.Version)
+}
+
+func (d *DeleteAclsRequest) requiredVersion() KafkaVersion {
+	switch d.Version {
+	case 1:
+		return V2_0_0_0
+	default:
+		return V0_11_0_0
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/acl_delete_response.go b/vendor/github.com/Shopify/sarama/acl_delete_response.go
new file mode 100644
index 0000000..6529565
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/acl_delete_response.go
@@ -0,0 +1,159 @@
+package sarama
+
+import "time"
+
+//DeleteAclsResponse is a delete acl response
+type DeleteAclsResponse struct {
+	Version         int16
+	ThrottleTime    time.Duration
+	FilterResponses []*FilterResponse
+}
+
+func (d *DeleteAclsResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(d.ThrottleTime / time.Millisecond))
+
+	if err := pe.putArrayLength(len(d.FilterResponses)); err != nil {
+		return err
+	}
+
+	for _, filterResponse := range d.FilterResponses {
+		if err := filterResponse.encode(pe, d.Version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (d *DeleteAclsResponse) decode(pd packetDecoder, version int16) (err error) {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	d.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	d.FilterResponses = make([]*FilterResponse, n)
+
+	for i := 0; i < n; i++ {
+		d.FilterResponses[i] = new(FilterResponse)
+		if err := d.FilterResponses[i].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (d *DeleteAclsResponse) key() int16 {
+	return 31
+}
+
+func (d *DeleteAclsResponse) version() int16 {
+	return int16(d.Version)
+}
+
+func (d *DeleteAclsResponse) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
+
+//FilterResponse is a filter response type
+type FilterResponse struct {
+	Err          KError
+	ErrMsg       *string
+	MatchingAcls []*MatchingAcl
+}
+
+func (f *FilterResponse) encode(pe packetEncoder, version int16) error {
+	pe.putInt16(int16(f.Err))
+	if err := pe.putNullableString(f.ErrMsg); err != nil {
+		return err
+	}
+
+	if err := pe.putArrayLength(len(f.MatchingAcls)); err != nil {
+		return err
+	}
+	for _, matchingAcl := range f.MatchingAcls {
+		if err := matchingAcl.encode(pe, version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (f *FilterResponse) decode(pd packetDecoder, version int16) (err error) {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	f.Err = KError(kerr)
+
+	if f.ErrMsg, err = pd.getNullableString(); err != nil {
+		return err
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	f.MatchingAcls = make([]*MatchingAcl, n)
+	for i := 0; i < n; i++ {
+		f.MatchingAcls[i] = new(MatchingAcl)
+		if err := f.MatchingAcls[i].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+//MatchingAcl is a matching acl type
+type MatchingAcl struct {
+	Err    KError
+	ErrMsg *string
+	Resource
+	Acl
+}
+
+func (m *MatchingAcl) encode(pe packetEncoder, version int16) error {
+	pe.putInt16(int16(m.Err))
+	if err := pe.putNullableString(m.ErrMsg); err != nil {
+		return err
+	}
+
+	if err := m.Resource.encode(pe, version); err != nil {
+		return err
+	}
+
+	if err := m.Acl.encode(pe); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (m *MatchingAcl) decode(pd packetDecoder, version int16) (err error) {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	m.Err = KError(kerr)
+
+	if m.ErrMsg, err = pd.getNullableString(); err != nil {
+		return err
+	}
+
+	if err := m.Resource.decode(pd, version); err != nil {
+		return err
+	}
+
+	if err := m.Acl.decode(pd, version); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/acl_describe_request.go b/vendor/github.com/Shopify/sarama/acl_describe_request.go
new file mode 100644
index 0000000..5222d46
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/acl_describe_request.go
@@ -0,0 +1,35 @@
+package sarama
+
+//DescribeAclsRequest is a secribe acl request type
+type DescribeAclsRequest struct {
+	Version int
+	AclFilter
+}
+
+func (d *DescribeAclsRequest) encode(pe packetEncoder) error {
+	d.AclFilter.Version = d.Version
+	return d.AclFilter.encode(pe)
+}
+
+func (d *DescribeAclsRequest) decode(pd packetDecoder, version int16) (err error) {
+	d.Version = int(version)
+	d.AclFilter.Version = int(version)
+	return d.AclFilter.decode(pd, version)
+}
+
+func (d *DescribeAclsRequest) key() int16 {
+	return 29
+}
+
+func (d *DescribeAclsRequest) version() int16 {
+	return int16(d.Version)
+}
+
+func (d *DescribeAclsRequest) requiredVersion() KafkaVersion {
+	switch d.Version {
+	case 1:
+		return V2_0_0_0
+	default:
+		return V0_11_0_0
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/acl_describe_response.go b/vendor/github.com/Shopify/sarama/acl_describe_response.go
new file mode 100644
index 0000000..12126e5
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/acl_describe_response.go
@@ -0,0 +1,87 @@
+package sarama
+
+import "time"
+
+//DescribeAclsResponse is a describe acl response type
+type DescribeAclsResponse struct {
+	Version      int16
+	ThrottleTime time.Duration
+	Err          KError
+	ErrMsg       *string
+	ResourceAcls []*ResourceAcls
+}
+
+func (d *DescribeAclsResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(d.ThrottleTime / time.Millisecond))
+	pe.putInt16(int16(d.Err))
+
+	if err := pe.putNullableString(d.ErrMsg); err != nil {
+		return err
+	}
+
+	if err := pe.putArrayLength(len(d.ResourceAcls)); err != nil {
+		return err
+	}
+
+	for _, resourceAcl := range d.ResourceAcls {
+		if err := resourceAcl.encode(pe, d.Version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (d *DescribeAclsResponse) decode(pd packetDecoder, version int16) (err error) {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	d.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	d.Err = KError(kerr)
+
+	errmsg, err := pd.getString()
+	if err != nil {
+		return err
+	}
+	if errmsg != "" {
+		d.ErrMsg = &errmsg
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	d.ResourceAcls = make([]*ResourceAcls, n)
+
+	for i := 0; i < n; i++ {
+		d.ResourceAcls[i] = new(ResourceAcls)
+		if err := d.ResourceAcls[i].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (d *DescribeAclsResponse) key() int16 {
+	return 29
+}
+
+func (d *DescribeAclsResponse) version() int16 {
+	return int16(d.Version)
+}
+
+func (d *DescribeAclsResponse) requiredVersion() KafkaVersion {
+	switch d.Version {
+	case 1:
+		return V2_0_0_0
+	default:
+		return V0_11_0_0
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/acl_filter.go b/vendor/github.com/Shopify/sarama/acl_filter.go
new file mode 100644
index 0000000..fad5558
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/acl_filter.go
@@ -0,0 +1,78 @@
+package sarama
+
+type AclFilter struct {
+	Version                   int
+	ResourceType              AclResourceType
+	ResourceName              *string
+	ResourcePatternTypeFilter AclResourcePatternType
+	Principal                 *string
+	Host                      *string
+	Operation                 AclOperation
+	PermissionType            AclPermissionType
+}
+
+func (a *AclFilter) encode(pe packetEncoder) error {
+	pe.putInt8(int8(a.ResourceType))
+	if err := pe.putNullableString(a.ResourceName); err != nil {
+		return err
+	}
+
+	if a.Version == 1 {
+		pe.putInt8(int8(a.ResourcePatternTypeFilter))
+	}
+
+	if err := pe.putNullableString(a.Principal); err != nil {
+		return err
+	}
+	if err := pe.putNullableString(a.Host); err != nil {
+		return err
+	}
+	pe.putInt8(int8(a.Operation))
+	pe.putInt8(int8(a.PermissionType))
+
+	return nil
+}
+
+func (a *AclFilter) decode(pd packetDecoder, version int16) (err error) {
+	resourceType, err := pd.getInt8()
+	if err != nil {
+		return err
+	}
+	a.ResourceType = AclResourceType(resourceType)
+
+	if a.ResourceName, err = pd.getNullableString(); err != nil {
+		return err
+	}
+
+	if a.Version == 1 {
+		pattern, err := pd.getInt8()
+
+		if err != nil {
+			return err
+		}
+
+		a.ResourcePatternTypeFilter = AclResourcePatternType(pattern)
+	}
+
+	if a.Principal, err = pd.getNullableString(); err != nil {
+		return err
+	}
+
+	if a.Host, err = pd.getNullableString(); err != nil {
+		return err
+	}
+
+	operation, err := pd.getInt8()
+	if err != nil {
+		return err
+	}
+	a.Operation = AclOperation(operation)
+
+	permissionType, err := pd.getInt8()
+	if err != nil {
+		return err
+	}
+	a.PermissionType = AclPermissionType(permissionType)
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/acl_types.go b/vendor/github.com/Shopify/sarama/acl_types.go
new file mode 100644
index 0000000..c10ad7b
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/acl_types.go
@@ -0,0 +1,55 @@
+package sarama
+
+type (
+	AclOperation int
+
+	AclPermissionType int
+
+	AclResourceType int
+
+	AclResourcePatternType int
+)
+
+// ref: https://github.com/apache/kafka/blob/trunk/clients/src/main/java/org/apache/kafka/common/acl/AclOperation.java
+const (
+	AclOperationUnknown AclOperation = iota
+	AclOperationAny
+	AclOperationAll
+	AclOperationRead
+	AclOperationWrite
+	AclOperationCreate
+	AclOperationDelete
+	AclOperationAlter
+	AclOperationDescribe
+	AclOperationClusterAction
+	AclOperationDescribeConfigs
+	AclOperationAlterConfigs
+	AclOperationIdempotentWrite
+)
+
+// ref: https://github.com/apache/kafka/blob/trunk/clients/src/main/java/org/apache/kafka/common/acl/AclPermissionType.java
+const (
+	AclPermissionUnknown AclPermissionType = iota
+	AclPermissionAny
+	AclPermissionDeny
+	AclPermissionAllow
+)
+
+// ref: https://github.com/apache/kafka/blob/trunk/clients/src/main/java/org/apache/kafka/common/resource/ResourceType.java
+const (
+	AclResourceUnknown AclResourceType = iota
+	AclResourceAny
+	AclResourceTopic
+	AclResourceGroup
+	AclResourceCluster
+	AclResourceTransactionalID
+)
+
+// ref: https://github.com/apache/kafka/blob/trunk/clients/src/main/java/org/apache/kafka/common/resource/PatternType.java
+const (
+	AclPatternUnknown AclResourcePatternType = iota
+	AclPatternAny
+	AclPatternMatch
+	AclPatternLiteral
+	AclPatternPrefixed
+)
diff --git a/vendor/github.com/Shopify/sarama/add_offsets_to_txn_request.go b/vendor/github.com/Shopify/sarama/add_offsets_to_txn_request.go
new file mode 100644
index 0000000..fc227ab
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/add_offsets_to_txn_request.go
@@ -0,0 +1,53 @@
+package sarama
+
+//AddOffsetsToTxnRequest adds offsets to a transaction request
+type AddOffsetsToTxnRequest struct {
+	TransactionalID string
+	ProducerID      int64
+	ProducerEpoch   int16
+	GroupID         string
+}
+
+func (a *AddOffsetsToTxnRequest) encode(pe packetEncoder) error {
+	if err := pe.putString(a.TransactionalID); err != nil {
+		return err
+	}
+
+	pe.putInt64(a.ProducerID)
+
+	pe.putInt16(a.ProducerEpoch)
+
+	if err := pe.putString(a.GroupID); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (a *AddOffsetsToTxnRequest) decode(pd packetDecoder, version int16) (err error) {
+	if a.TransactionalID, err = pd.getString(); err != nil {
+		return err
+	}
+	if a.ProducerID, err = pd.getInt64(); err != nil {
+		return err
+	}
+	if a.ProducerEpoch, err = pd.getInt16(); err != nil {
+		return err
+	}
+	if a.GroupID, err = pd.getString(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (a *AddOffsetsToTxnRequest) key() int16 {
+	return 25
+}
+
+func (a *AddOffsetsToTxnRequest) version() int16 {
+	return 0
+}
+
+func (a *AddOffsetsToTxnRequest) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/add_offsets_to_txn_response.go b/vendor/github.com/Shopify/sarama/add_offsets_to_txn_response.go
new file mode 100644
index 0000000..c88c1f8
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/add_offsets_to_txn_response.go
@@ -0,0 +1,45 @@
+package sarama
+
+import (
+	"time"
+)
+
+//AddOffsetsToTxnResponse is a response type for adding offsets to txns
+type AddOffsetsToTxnResponse struct {
+	ThrottleTime time.Duration
+	Err          KError
+}
+
+func (a *AddOffsetsToTxnResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(a.ThrottleTime / time.Millisecond))
+	pe.putInt16(int16(a.Err))
+	return nil
+}
+
+func (a *AddOffsetsToTxnResponse) decode(pd packetDecoder, version int16) (err error) {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	a.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	a.Err = KError(kerr)
+
+	return nil
+}
+
+func (a *AddOffsetsToTxnResponse) key() int16 {
+	return 25
+}
+
+func (a *AddOffsetsToTxnResponse) version() int16 {
+	return 0
+}
+
+func (a *AddOffsetsToTxnResponse) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/add_partitions_to_txn_request.go b/vendor/github.com/Shopify/sarama/add_partitions_to_txn_request.go
new file mode 100644
index 0000000..8d4b42e
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/add_partitions_to_txn_request.go
@@ -0,0 +1,77 @@
+package sarama
+
+//AddPartitionsToTxnRequest is a add paartition request
+type AddPartitionsToTxnRequest struct {
+	TransactionalID string
+	ProducerID      int64
+	ProducerEpoch   int16
+	TopicPartitions map[string][]int32
+}
+
+func (a *AddPartitionsToTxnRequest) encode(pe packetEncoder) error {
+	if err := pe.putString(a.TransactionalID); err != nil {
+		return err
+	}
+	pe.putInt64(a.ProducerID)
+	pe.putInt16(a.ProducerEpoch)
+
+	if err := pe.putArrayLength(len(a.TopicPartitions)); err != nil {
+		return err
+	}
+	for topic, partitions := range a.TopicPartitions {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putInt32Array(partitions); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (a *AddPartitionsToTxnRequest) decode(pd packetDecoder, version int16) (err error) {
+	if a.TransactionalID, err = pd.getString(); err != nil {
+		return err
+	}
+	if a.ProducerID, err = pd.getInt64(); err != nil {
+		return err
+	}
+	if a.ProducerEpoch, err = pd.getInt16(); err != nil {
+		return err
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	a.TopicPartitions = make(map[string][]int32)
+	for i := 0; i < n; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		partitions, err := pd.getInt32Array()
+		if err != nil {
+			return err
+		}
+
+		a.TopicPartitions[topic] = partitions
+	}
+
+	return nil
+}
+
+func (a *AddPartitionsToTxnRequest) key() int16 {
+	return 24
+}
+
+func (a *AddPartitionsToTxnRequest) version() int16 {
+	return 0
+}
+
+func (a *AddPartitionsToTxnRequest) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/add_partitions_to_txn_response.go b/vendor/github.com/Shopify/sarama/add_partitions_to_txn_response.go
new file mode 100644
index 0000000..eb4f23e
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/add_partitions_to_txn_response.go
@@ -0,0 +1,110 @@
+package sarama
+
+import (
+	"time"
+)
+
+//AddPartitionsToTxnResponse is a partition errors to transaction type
+type AddPartitionsToTxnResponse struct {
+	ThrottleTime time.Duration
+	Errors       map[string][]*PartitionError
+}
+
+func (a *AddPartitionsToTxnResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(a.ThrottleTime / time.Millisecond))
+	if err := pe.putArrayLength(len(a.Errors)); err != nil {
+		return err
+	}
+
+	for topic, e := range a.Errors {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putArrayLength(len(e)); err != nil {
+			return err
+		}
+		for _, partitionError := range e {
+			if err := partitionError.encode(pe); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (a *AddPartitionsToTxnResponse) decode(pd packetDecoder, version int16) (err error) {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	a.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	a.Errors = make(map[string][]*PartitionError)
+
+	for i := 0; i < n; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		m, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+
+		a.Errors[topic] = make([]*PartitionError, m)
+
+		for j := 0; j < m; j++ {
+			a.Errors[topic][j] = new(PartitionError)
+			if err := a.Errors[topic][j].decode(pd, version); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (a *AddPartitionsToTxnResponse) key() int16 {
+	return 24
+}
+
+func (a *AddPartitionsToTxnResponse) version() int16 {
+	return 0
+}
+
+func (a *AddPartitionsToTxnResponse) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
+
+//PartitionError is a partition error type
+type PartitionError struct {
+	Partition int32
+	Err       KError
+}
+
+func (p *PartitionError) encode(pe packetEncoder) error {
+	pe.putInt32(p.Partition)
+	pe.putInt16(int16(p.Err))
+	return nil
+}
+
+func (p *PartitionError) decode(pd packetDecoder, version int16) (err error) {
+	if p.Partition, err = pd.getInt32(); err != nil {
+		return err
+	}
+
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	p.Err = KError(kerr)
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/admin.go b/vendor/github.com/Shopify/sarama/admin.go
new file mode 100644
index 0000000..6c9b1e9
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/admin.go
@@ -0,0 +1,690 @@
+package sarama
+
+import (
+	"errors"
+	"math/rand"
+	"sync"
+)
+
+// ClusterAdmin is the administrative client for Kafka, which supports managing and inspecting topics,
+// brokers, configurations and ACLs. The minimum broker version required is 0.10.0.0.
+// Methods with stricter requirements will specify the minimum broker version required.
+// You MUST call Close() on a client to avoid leaks
+type ClusterAdmin interface {
+	// Creates a new topic. This operation is supported by brokers with version 0.10.1.0 or higher.
+	// It may take several seconds after CreateTopic returns success for all the brokers
+	// to become aware that the topic has been created. During this time, listTopics
+	// may not return information about the new topic.The validateOnly option is supported from version 0.10.2.0.
+	CreateTopic(topic string, detail *TopicDetail, validateOnly bool) error
+
+	// List the topics available in the cluster with the default options.
+	ListTopics() (map[string]TopicDetail, error)
+
+	// Describe some topics in the cluster.
+	DescribeTopics(topics []string) (metadata []*TopicMetadata, err error)
+
+	// Delete a topic. It may take several seconds after the DeleteTopic to returns success
+	// and for all the brokers to become aware that the topics are gone.
+	// During this time, listTopics  may continue to return information about the deleted topic.
+	// If delete.topic.enable is false on the brokers, deleteTopic will mark
+	// the topic for deletion, but not actually delete them.
+	// This operation is supported by brokers with version 0.10.1.0 or higher.
+	DeleteTopic(topic string) error
+
+	// Increase the number of partitions of the topics  according to the corresponding values.
+	// If partitions are increased for a topic that has a key, the partition logic or ordering of
+	// the messages will be affected. It may take several seconds after this method returns
+	// success for all the brokers to become aware that the partitions have been created.
+	// During this time, ClusterAdmin#describeTopics may not return information about the
+	// new partitions. This operation is supported by brokers with version 1.0.0 or higher.
+	CreatePartitions(topic string, count int32, assignment [][]int32, validateOnly bool) error
+
+	// Delete records whose offset is smaller than the given offset of the corresponding partition.
+	// This operation is supported by brokers with version 0.11.0.0 or higher.
+	DeleteRecords(topic string, partitionOffsets map[int32]int64) error
+
+	// Get the configuration for the specified resources.
+	// The returned configuration includes default values and the Default is true
+	// can be used to distinguish them from user supplied values.
+	// Config entries where ReadOnly is true cannot be updated.
+	// The value of config entries where Sensitive is true is always nil so
+	// sensitive information is not disclosed.
+	// This operation is supported by brokers with version 0.11.0.0 or higher.
+	DescribeConfig(resource ConfigResource) ([]ConfigEntry, error)
+
+	// Update the configuration for the specified resources with the default options.
+	// This operation is supported by brokers with version 0.11.0.0 or higher.
+	// The resources with their configs (topic is the only resource type with configs
+	// that can be updated currently Updates are not transactional so they may succeed
+	// for some resources while fail for others. The configs for a particular resource are updated automatically.
+	AlterConfig(resourceType ConfigResourceType, name string, entries map[string]*string, validateOnly bool) error
+
+	// Creates access control lists (ACLs) which are bound to specific resources.
+	// This operation is not transactional so it may succeed for some ACLs while fail for others.
+	// If you attempt to add an ACL that duplicates an existing ACL, no error will be raised, but
+	// no changes will be made. This operation is supported by brokers with version 0.11.0.0 or higher.
+	CreateACL(resource Resource, acl Acl) error
+
+	// Lists access control lists (ACLs) according to the supplied filter.
+	// it may take some time for changes made by createAcls or deleteAcls to be reflected in the output of ListAcls
+	// This operation is supported by brokers with version 0.11.0.0 or higher.
+	ListAcls(filter AclFilter) ([]ResourceAcls, error)
+
+	// Deletes access control lists (ACLs) according to the supplied filters.
+	// This operation is not transactional so it may succeed for some ACLs while fail for others.
+	// This operation is supported by brokers with version 0.11.0.0 or higher.
+	DeleteACL(filter AclFilter, validateOnly bool) ([]MatchingAcl, error)
+
+	// List the consumer groups available in the cluster.
+	ListConsumerGroups() (map[string]string, error)
+
+	// Describe the given consumer groups.
+	DescribeConsumerGroups(groups []string) ([]*GroupDescription, error)
+
+	// List the consumer group offsets available in the cluster.
+	ListConsumerGroupOffsets(group string, topicPartitions map[string][]int32) (*OffsetFetchResponse, error)
+
+	// Delete a consumer group.
+	DeleteConsumerGroup(group string) error
+
+	// Get information about the nodes in the cluster
+	DescribeCluster() (brokers []*Broker, controllerID int32, err error)
+
+	// Close shuts down the admin and closes underlying client.
+	Close() error
+}
+
+type clusterAdmin struct {
+	client Client
+	conf   *Config
+}
+
+// NewClusterAdmin creates a new ClusterAdmin using the given broker addresses and configuration.
+func NewClusterAdmin(addrs []string, conf *Config) (ClusterAdmin, error) {
+	client, err := NewClient(addrs, conf)
+	if err != nil {
+		return nil, err
+	}
+	return NewClusterAdminFromClient(client)
+}
+
+// NewClusterAdminFromClient creates a new ClusterAdmin using the given client.
+// Note that underlying client will also be closed on admin's Close() call.
+func NewClusterAdminFromClient(client Client) (ClusterAdmin, error) {
+	//make sure we can retrieve the controller
+	_, err := client.Controller()
+	if err != nil {
+		return nil, err
+	}
+
+	ca := &clusterAdmin{
+		client: client,
+		conf:   client.Config(),
+	}
+	return ca, nil
+}
+
+func (ca *clusterAdmin) Close() error {
+	return ca.client.Close()
+}
+
+func (ca *clusterAdmin) Controller() (*Broker, error) {
+	return ca.client.Controller()
+}
+
+func (ca *clusterAdmin) CreateTopic(topic string, detail *TopicDetail, validateOnly bool) error {
+
+	if topic == "" {
+		return ErrInvalidTopic
+	}
+
+	if detail == nil {
+		return errors.New("you must specify topic details")
+	}
+
+	topicDetails := make(map[string]*TopicDetail)
+	topicDetails[topic] = detail
+
+	request := &CreateTopicsRequest{
+		TopicDetails: topicDetails,
+		ValidateOnly: validateOnly,
+		Timeout:      ca.conf.Admin.Timeout,
+	}
+
+	if ca.conf.Version.IsAtLeast(V0_11_0_0) {
+		request.Version = 1
+	}
+	if ca.conf.Version.IsAtLeast(V1_0_0_0) {
+		request.Version = 2
+	}
+
+	b, err := ca.Controller()
+	if err != nil {
+		return err
+	}
+
+	rsp, err := b.CreateTopics(request)
+	if err != nil {
+		return err
+	}
+
+	topicErr, ok := rsp.TopicErrors[topic]
+	if !ok {
+		return ErrIncompleteResponse
+	}
+
+	if topicErr.Err != ErrNoError {
+		return topicErr
+	}
+
+	return nil
+}
+
+func (ca *clusterAdmin) DescribeTopics(topics []string) (metadata []*TopicMetadata, err error) {
+	controller, err := ca.Controller()
+	if err != nil {
+		return nil, err
+	}
+
+	request := &MetadataRequest{
+		Topics:                 topics,
+		AllowAutoTopicCreation: false,
+	}
+
+	if ca.conf.Version.IsAtLeast(V1_0_0_0) {
+		request.Version = 5
+	} else if ca.conf.Version.IsAtLeast(V0_11_0_0) {
+		request.Version = 4
+	}
+
+	response, err := controller.GetMetadata(request)
+	if err != nil {
+		return nil, err
+	}
+	return response.Topics, nil
+}
+
+func (ca *clusterAdmin) DescribeCluster() (brokers []*Broker, controllerID int32, err error) {
+	controller, err := ca.Controller()
+	if err != nil {
+		return nil, int32(0), err
+	}
+
+	request := &MetadataRequest{
+		Topics: []string{},
+	}
+
+	if ca.conf.Version.IsAtLeast(V0_11_0_0) {
+		request.Version = 1
+	}
+
+	response, err := controller.GetMetadata(request)
+	if err != nil {
+		return nil, int32(0), err
+	}
+
+	return response.Brokers, response.ControllerID, nil
+}
+
+func (ca *clusterAdmin) findAnyBroker() (*Broker, error) {
+	brokers := ca.client.Brokers()
+	if len(brokers) > 0 {
+		index := rand.Intn(len(brokers))
+		return brokers[index], nil
+	}
+	return nil, errors.New("no available broker")
+}
+
+func (ca *clusterAdmin) ListTopics() (map[string]TopicDetail, error) {
+	// In order to build TopicDetails we need to first get the list of all
+	// topics using a MetadataRequest and then get their configs using a
+	// DescribeConfigsRequest request. To avoid sending many requests to the
+	// broker, we use a single DescribeConfigsRequest.
+
+	// Send the all-topic MetadataRequest
+	b, err := ca.findAnyBroker()
+	if err != nil {
+		return nil, err
+	}
+	_ = b.Open(ca.client.Config())
+
+	metadataReq := &MetadataRequest{}
+	metadataResp, err := b.GetMetadata(metadataReq)
+	if err != nil {
+		return nil, err
+	}
+
+	topicsDetailsMap := make(map[string]TopicDetail)
+
+	var describeConfigsResources []*ConfigResource
+
+	for _, topic := range metadataResp.Topics {
+		topicDetails := TopicDetail{
+			NumPartitions: int32(len(topic.Partitions)),
+		}
+		if len(topic.Partitions) > 0 {
+			topicDetails.ReplicaAssignment = map[int32][]int32{}
+			for _, partition := range topic.Partitions {
+				topicDetails.ReplicaAssignment[partition.ID] = partition.Replicas
+			}
+			topicDetails.ReplicationFactor = int16(len(topic.Partitions[0].Replicas))
+		}
+		topicsDetailsMap[topic.Name] = topicDetails
+
+		// we populate the resources we want to describe from the MetadataResponse
+		topicResource := ConfigResource{
+			Type: TopicResource,
+			Name: topic.Name,
+		}
+		describeConfigsResources = append(describeConfigsResources, &topicResource)
+	}
+
+	// Send the DescribeConfigsRequest
+	describeConfigsReq := &DescribeConfigsRequest{
+		Resources: describeConfigsResources,
+	}
+	describeConfigsResp, err := b.DescribeConfigs(describeConfigsReq)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, resource := range describeConfigsResp.Resources {
+		topicDetails := topicsDetailsMap[resource.Name]
+		topicDetails.ConfigEntries = make(map[string]*string)
+
+		for _, entry := range resource.Configs {
+			// only include non-default non-sensitive config
+			// (don't actually think topic config will ever be sensitive)
+			if entry.Default || entry.Sensitive {
+				continue
+			}
+			topicDetails.ConfigEntries[entry.Name] = &entry.Value
+		}
+
+		topicsDetailsMap[resource.Name] = topicDetails
+	}
+
+	return topicsDetailsMap, nil
+}
+
+func (ca *clusterAdmin) DeleteTopic(topic string) error {
+
+	if topic == "" {
+		return ErrInvalidTopic
+	}
+
+	request := &DeleteTopicsRequest{
+		Topics:  []string{topic},
+		Timeout: ca.conf.Admin.Timeout,
+	}
+
+	if ca.conf.Version.IsAtLeast(V0_11_0_0) {
+		request.Version = 1
+	}
+
+	b, err := ca.Controller()
+	if err != nil {
+		return err
+	}
+
+	rsp, err := b.DeleteTopics(request)
+	if err != nil {
+		return err
+	}
+
+	topicErr, ok := rsp.TopicErrorCodes[topic]
+	if !ok {
+		return ErrIncompleteResponse
+	}
+
+	if topicErr != ErrNoError {
+		return topicErr
+	}
+	return nil
+}
+
+func (ca *clusterAdmin) CreatePartitions(topic string, count int32, assignment [][]int32, validateOnly bool) error {
+	if topic == "" {
+		return ErrInvalidTopic
+	}
+
+	topicPartitions := make(map[string]*TopicPartition)
+	topicPartitions[topic] = &TopicPartition{Count: count, Assignment: assignment}
+
+	request := &CreatePartitionsRequest{
+		TopicPartitions: topicPartitions,
+		Timeout:         ca.conf.Admin.Timeout,
+	}
+
+	b, err := ca.Controller()
+	if err != nil {
+		return err
+	}
+
+	rsp, err := b.CreatePartitions(request)
+	if err != nil {
+		return err
+	}
+
+	topicErr, ok := rsp.TopicPartitionErrors[topic]
+	if !ok {
+		return ErrIncompleteResponse
+	}
+
+	if topicErr.Err != ErrNoError {
+		return topicErr
+	}
+
+	return nil
+}
+
+func (ca *clusterAdmin) DeleteRecords(topic string, partitionOffsets map[int32]int64) error {
+
+	if topic == "" {
+		return ErrInvalidTopic
+	}
+	partitionPerBroker := make(map[*Broker][]int32)
+	for partition := range partitionOffsets {
+		broker, err := ca.client.Leader(topic, partition)
+		if err != nil {
+			return err
+		}
+		if _, ok := partitionPerBroker[broker]; ok {
+			partitionPerBroker[broker] = append(partitionPerBroker[broker], partition)
+		} else {
+			partitionPerBroker[broker] = []int32{partition}
+		}
+	}
+	errs := make([]error, 0)
+	for broker, partitions := range partitionPerBroker {
+		topics := make(map[string]*DeleteRecordsRequestTopic)
+		recordsToDelete := make(map[int32]int64)
+		for _, p := range partitions {
+			recordsToDelete[p] = partitionOffsets[p]
+		}
+		topics[topic] = &DeleteRecordsRequestTopic{PartitionOffsets: recordsToDelete}
+		request := &DeleteRecordsRequest{
+			Topics:  topics,
+			Timeout: ca.conf.Admin.Timeout,
+		}
+
+		rsp, err := broker.DeleteRecords(request)
+		if err != nil {
+			errs = append(errs, err)
+		} else {
+			deleteRecordsResponseTopic, ok := rsp.Topics[topic]
+			if !ok {
+				errs = append(errs, ErrIncompleteResponse)
+			} else {
+				for _, deleteRecordsResponsePartition := range deleteRecordsResponseTopic.Partitions {
+					if deleteRecordsResponsePartition.Err != ErrNoError {
+						errs = append(errs, errors.New(deleteRecordsResponsePartition.Err.Error()))
+					}
+				}
+			}
+		}
+	}
+	if len(errs) > 0 {
+		return ErrDeleteRecords{MultiError{&errs}}
+	}
+	//todo since we are dealing with couple of partitions it would be good if we return slice of errors
+	//for each partition instead of one error
+	return nil
+}
+
+func (ca *clusterAdmin) DescribeConfig(resource ConfigResource) ([]ConfigEntry, error) {
+
+	var entries []ConfigEntry
+	var resources []*ConfigResource
+	resources = append(resources, &resource)
+
+	request := &DescribeConfigsRequest{
+		Resources: resources,
+	}
+
+	b, err := ca.Controller()
+	if err != nil {
+		return nil, err
+	}
+
+	rsp, err := b.DescribeConfigs(request)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, rspResource := range rsp.Resources {
+		if rspResource.Name == resource.Name {
+			if rspResource.ErrorMsg != "" {
+				return nil, errors.New(rspResource.ErrorMsg)
+			}
+			for _, cfgEntry := range rspResource.Configs {
+				entries = append(entries, *cfgEntry)
+			}
+		}
+	}
+	return entries, nil
+}
+
+func (ca *clusterAdmin) AlterConfig(resourceType ConfigResourceType, name string, entries map[string]*string, validateOnly bool) error {
+
+	var resources []*AlterConfigsResource
+	resources = append(resources, &AlterConfigsResource{
+		Type:          resourceType,
+		Name:          name,
+		ConfigEntries: entries,
+	})
+
+	request := &AlterConfigsRequest{
+		Resources:    resources,
+		ValidateOnly: validateOnly,
+	}
+
+	b, err := ca.Controller()
+	if err != nil {
+		return err
+	}
+
+	rsp, err := b.AlterConfigs(request)
+	if err != nil {
+		return err
+	}
+
+	for _, rspResource := range rsp.Resources {
+		if rspResource.Name == name {
+			if rspResource.ErrorMsg != "" {
+				return errors.New(rspResource.ErrorMsg)
+			}
+		}
+	}
+	return nil
+}
+
+func (ca *clusterAdmin) CreateACL(resource Resource, acl Acl) error {
+	var acls []*AclCreation
+	acls = append(acls, &AclCreation{resource, acl})
+	request := &CreateAclsRequest{AclCreations: acls}
+
+	if ca.conf.Version.IsAtLeast(V2_0_0_0) {
+		request.Version = 1
+	}
+
+	b, err := ca.Controller()
+	if err != nil {
+		return err
+	}
+
+	_, err = b.CreateAcls(request)
+	return err
+}
+
+func (ca *clusterAdmin) ListAcls(filter AclFilter) ([]ResourceAcls, error) {
+
+	request := &DescribeAclsRequest{AclFilter: filter}
+
+	if ca.conf.Version.IsAtLeast(V2_0_0_0) {
+		request.Version = 1
+	}
+
+	b, err := ca.Controller()
+	if err != nil {
+		return nil, err
+	}
+
+	rsp, err := b.DescribeAcls(request)
+	if err != nil {
+		return nil, err
+	}
+
+	var lAcls []ResourceAcls
+	for _, rAcl := range rsp.ResourceAcls {
+		lAcls = append(lAcls, *rAcl)
+	}
+	return lAcls, nil
+}
+
+func (ca *clusterAdmin) DeleteACL(filter AclFilter, validateOnly bool) ([]MatchingAcl, error) {
+	var filters []*AclFilter
+	filters = append(filters, &filter)
+	request := &DeleteAclsRequest{Filters: filters}
+
+	if ca.conf.Version.IsAtLeast(V2_0_0_0) {
+		request.Version = 1
+	}
+
+	b, err := ca.Controller()
+	if err != nil {
+		return nil, err
+	}
+
+	rsp, err := b.DeleteAcls(request)
+	if err != nil {
+		return nil, err
+	}
+
+	var mAcls []MatchingAcl
+	for _, fr := range rsp.FilterResponses {
+		for _, mACL := range fr.MatchingAcls {
+			mAcls = append(mAcls, *mACL)
+		}
+
+	}
+	return mAcls, nil
+}
+
+func (ca *clusterAdmin) DescribeConsumerGroups(groups []string) (result []*GroupDescription, err error) {
+	groupsPerBroker := make(map[*Broker][]string)
+
+	for _, group := range groups {
+		controller, err := ca.client.Coordinator(group)
+		if err != nil {
+			return nil, err
+		}
+		groupsPerBroker[controller] = append(groupsPerBroker[controller], group)
+
+	}
+
+	for broker, brokerGroups := range groupsPerBroker {
+		response, err := broker.DescribeGroups(&DescribeGroupsRequest{
+			Groups: brokerGroups,
+		})
+		if err != nil {
+			return nil, err
+		}
+
+		result = append(result, response.Groups...)
+	}
+	return result, nil
+}
+
+func (ca *clusterAdmin) ListConsumerGroups() (allGroups map[string]string, err error) {
+	allGroups = make(map[string]string)
+
+	// Query brokers in parallel, since we have to query *all* brokers
+	brokers := ca.client.Brokers()
+	groupMaps := make(chan map[string]string, len(brokers))
+	errors := make(chan error, len(brokers))
+	wg := sync.WaitGroup{}
+
+	for _, b := range brokers {
+		wg.Add(1)
+		go func(b *Broker, conf *Config) {
+			defer wg.Done()
+			_ = b.Open(conf) // Ensure that broker is opened
+
+			response, err := b.ListGroups(&ListGroupsRequest{})
+			if err != nil {
+				errors <- err
+				return
+			}
+
+			groups := make(map[string]string)
+			for group, typ := range response.Groups {
+				groups[group] = typ
+			}
+
+			groupMaps <- groups
+
+		}(b, ca.conf)
+	}
+
+	wg.Wait()
+	close(groupMaps)
+	close(errors)
+
+	for groupMap := range groupMaps {
+		for group, protocolType := range groupMap {
+			allGroups[group] = protocolType
+		}
+	}
+
+	// Intentionally return only the first error for simplicity
+	err = <-errors
+	return
+}
+
+func (ca *clusterAdmin) ListConsumerGroupOffsets(group string, topicPartitions map[string][]int32) (*OffsetFetchResponse, error) {
+	coordinator, err := ca.client.Coordinator(group)
+	if err != nil {
+		return nil, err
+	}
+
+	request := &OffsetFetchRequest{
+		ConsumerGroup: group,
+		partitions:    topicPartitions,
+	}
+
+	if ca.conf.Version.IsAtLeast(V0_10_2_0) {
+		request.Version = 2
+	} else if ca.conf.Version.IsAtLeast(V0_8_2_2) {
+		request.Version = 1
+	}
+
+	return coordinator.FetchOffset(request)
+}
+
+func (ca *clusterAdmin) DeleteConsumerGroup(group string) error {
+	coordinator, err := ca.client.Coordinator(group)
+	if err != nil {
+		return err
+	}
+
+	request := &DeleteGroupsRequest{
+		Groups: []string{group},
+	}
+
+	resp, err := coordinator.DeleteGroups(request)
+	if err != nil {
+		return err
+	}
+
+	groupErr, ok := resp.GroupErrorCodes[group]
+	if !ok {
+		return ErrIncompleteResponse
+	}
+
+	if groupErr != ErrNoError {
+		return groupErr
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/alter_configs_request.go b/vendor/github.com/Shopify/sarama/alter_configs_request.go
new file mode 100644
index 0000000..26c275b
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/alter_configs_request.go
@@ -0,0 +1,122 @@
+package sarama
+
+//AlterConfigsRequest is an alter config request type
+type AlterConfigsRequest struct {
+	Resources    []*AlterConfigsResource
+	ValidateOnly bool
+}
+
+//AlterConfigsResource is an alter config resource type
+type AlterConfigsResource struct {
+	Type          ConfigResourceType
+	Name          string
+	ConfigEntries map[string]*string
+}
+
+func (a *AlterConfigsRequest) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(a.Resources)); err != nil {
+		return err
+	}
+
+	for _, r := range a.Resources {
+		if err := r.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	pe.putBool(a.ValidateOnly)
+	return nil
+}
+
+func (a *AlterConfigsRequest) decode(pd packetDecoder, version int16) error {
+	resourceCount, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	a.Resources = make([]*AlterConfigsResource, resourceCount)
+	for i := range a.Resources {
+		r := &AlterConfigsResource{}
+		err = r.decode(pd, version)
+		if err != nil {
+			return err
+		}
+		a.Resources[i] = r
+	}
+
+	validateOnly, err := pd.getBool()
+	if err != nil {
+		return err
+	}
+
+	a.ValidateOnly = validateOnly
+
+	return nil
+}
+
+func (a *AlterConfigsResource) encode(pe packetEncoder) error {
+	pe.putInt8(int8(a.Type))
+
+	if err := pe.putString(a.Name); err != nil {
+		return err
+	}
+
+	if err := pe.putArrayLength(len(a.ConfigEntries)); err != nil {
+		return err
+	}
+	for configKey, configValue := range a.ConfigEntries {
+		if err := pe.putString(configKey); err != nil {
+			return err
+		}
+		if err := pe.putNullableString(configValue); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (a *AlterConfigsResource) decode(pd packetDecoder, version int16) error {
+	t, err := pd.getInt8()
+	if err != nil {
+		return err
+	}
+	a.Type = ConfigResourceType(t)
+
+	name, err := pd.getString()
+	if err != nil {
+		return err
+	}
+	a.Name = name
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	if n > 0 {
+		a.ConfigEntries = make(map[string]*string, n)
+		for i := 0; i < n; i++ {
+			configKey, err := pd.getString()
+			if err != nil {
+				return err
+			}
+			if a.ConfigEntries[configKey], err = pd.getNullableString(); err != nil {
+				return err
+			}
+		}
+	}
+	return err
+}
+
+func (a *AlterConfigsRequest) key() int16 {
+	return 33
+}
+
+func (a *AlterConfigsRequest) version() int16 {
+	return 0
+}
+
+func (a *AlterConfigsRequest) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/alter_configs_response.go b/vendor/github.com/Shopify/sarama/alter_configs_response.go
new file mode 100644
index 0000000..3893663
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/alter_configs_response.go
@@ -0,0 +1,97 @@
+package sarama
+
+import "time"
+
+//AlterConfigsResponse is a reponse type for alter config
+type AlterConfigsResponse struct {
+	ThrottleTime time.Duration
+	Resources    []*AlterConfigsResourceResponse
+}
+
+//AlterConfigsResourceResponse is a reponse type for alter config resource
+type AlterConfigsResourceResponse struct {
+	ErrorCode int16
+	ErrorMsg  string
+	Type      ConfigResourceType
+	Name      string
+}
+
+func (a *AlterConfigsResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(a.ThrottleTime / time.Millisecond))
+
+	if err := pe.putArrayLength(len(a.Resources)); err != nil {
+		return err
+	}
+
+	for i := range a.Resources {
+		pe.putInt16(a.Resources[i].ErrorCode)
+		err := pe.putString(a.Resources[i].ErrorMsg)
+		if err != nil {
+			return nil
+		}
+		pe.putInt8(int8(a.Resources[i].Type))
+		err = pe.putString(a.Resources[i].Name)
+		if err != nil {
+			return nil
+		}
+	}
+
+	return nil
+}
+
+func (a *AlterConfigsResponse) decode(pd packetDecoder, version int16) error {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	a.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	responseCount, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	a.Resources = make([]*AlterConfigsResourceResponse, responseCount)
+
+	for i := range a.Resources {
+		a.Resources[i] = new(AlterConfigsResourceResponse)
+
+		errCode, err := pd.getInt16()
+		if err != nil {
+			return err
+		}
+		a.Resources[i].ErrorCode = errCode
+
+		e, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		a.Resources[i].ErrorMsg = e
+
+		t, err := pd.getInt8()
+		if err != nil {
+			return err
+		}
+		a.Resources[i].Type = ConfigResourceType(t)
+
+		name, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		a.Resources[i].Name = name
+	}
+
+	return nil
+}
+
+func (a *AlterConfigsResponse) key() int16 {
+	return 32
+}
+
+func (a *AlterConfigsResponse) version() int16 {
+	return 0
+}
+
+func (a *AlterConfigsResponse) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/api_versions_request.go b/vendor/github.com/Shopify/sarama/api_versions_request.go
new file mode 100644
index 0000000..b33167c
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/api_versions_request.go
@@ -0,0 +1,25 @@
+package sarama
+
+//ApiVersionsRequest ...
+type ApiVersionsRequest struct {
+}
+
+func (a *ApiVersionsRequest) encode(pe packetEncoder) error {
+	return nil
+}
+
+func (a *ApiVersionsRequest) decode(pd packetDecoder, version int16) (err error) {
+	return nil
+}
+
+func (a *ApiVersionsRequest) key() int16 {
+	return 18
+}
+
+func (a *ApiVersionsRequest) version() int16 {
+	return 0
+}
+
+func (a *ApiVersionsRequest) requiredVersion() KafkaVersion {
+	return V0_10_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/api_versions_response.go b/vendor/github.com/Shopify/sarama/api_versions_response.go
new file mode 100644
index 0000000..bb1f0b3
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/api_versions_response.go
@@ -0,0 +1,89 @@
+package sarama
+
+//ApiVersionsResponseBlock is an api version reponse block type
+type ApiVersionsResponseBlock struct {
+	ApiKey     int16
+	MinVersion int16
+	MaxVersion int16
+}
+
+func (b *ApiVersionsResponseBlock) encode(pe packetEncoder) error {
+	pe.putInt16(b.ApiKey)
+	pe.putInt16(b.MinVersion)
+	pe.putInt16(b.MaxVersion)
+	return nil
+}
+
+func (b *ApiVersionsResponseBlock) decode(pd packetDecoder) error {
+	var err error
+
+	if b.ApiKey, err = pd.getInt16(); err != nil {
+		return err
+	}
+
+	if b.MinVersion, err = pd.getInt16(); err != nil {
+		return err
+	}
+
+	if b.MaxVersion, err = pd.getInt16(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+//ApiVersionsResponse is an api version response type
+type ApiVersionsResponse struct {
+	Err         KError
+	ApiVersions []*ApiVersionsResponseBlock
+}
+
+func (r *ApiVersionsResponse) encode(pe packetEncoder) error {
+	pe.putInt16(int16(r.Err))
+	if err := pe.putArrayLength(len(r.ApiVersions)); err != nil {
+		return err
+	}
+	for _, apiVersion := range r.ApiVersions {
+		if err := apiVersion.encode(pe); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (r *ApiVersionsResponse) decode(pd packetDecoder, version int16) error {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+
+	r.Err = KError(kerr)
+
+	numBlocks, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.ApiVersions = make([]*ApiVersionsResponseBlock, numBlocks)
+	for i := 0; i < numBlocks; i++ {
+		block := new(ApiVersionsResponseBlock)
+		if err := block.decode(pd); err != nil {
+			return err
+		}
+		r.ApiVersions[i] = block
+	}
+
+	return nil
+}
+
+func (r *ApiVersionsResponse) key() int16 {
+	return 18
+}
+
+func (r *ApiVersionsResponse) version() int16 {
+	return 0
+}
+
+func (r *ApiVersionsResponse) requiredVersion() KafkaVersion {
+	return V0_10_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/async_producer.go b/vendor/github.com/Shopify/sarama/async_producer.go
new file mode 100644
index 0000000..9b15cd1
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/async_producer.go
@@ -0,0 +1,1116 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/eapache/go-resiliency/breaker"
+	"github.com/eapache/queue"
+)
+
+// AsyncProducer publishes Kafka messages using a non-blocking API. It routes messages
+// to the correct broker for the provided topic-partition, refreshing metadata as appropriate,
+// and parses responses for errors. You must read from the Errors() channel or the
+// producer will deadlock. You must call Close() or AsyncClose() on a producer to avoid
+// leaks: it will not be garbage-collected automatically when it passes out of
+// scope.
+type AsyncProducer interface {
+
+	// AsyncClose triggers a shutdown of the producer. The shutdown has completed
+	// when both the Errors and Successes channels have been closed. When calling
+	// AsyncClose, you *must* continue to read from those channels in order to
+	// drain the results of any messages in flight.
+	AsyncClose()
+
+	// Close shuts down the producer and waits for any buffered messages to be
+	// flushed. You must call this function before a producer object passes out of
+	// scope, as it may otherwise leak memory. You must call this before calling
+	// Close on the underlying client.
+	Close() error
+
+	// Input is the input channel for the user to write messages to that they
+	// wish to send.
+	Input() chan<- *ProducerMessage
+
+	// Successes is the success output channel back to the user when Return.Successes is
+	// enabled. If Return.Successes is true, you MUST read from this channel or the
+	// Producer will deadlock. It is suggested that you send and read messages
+	// together in a single select statement.
+	Successes() <-chan *ProducerMessage
+
+	// Errors is the error output channel back to the user. You MUST read from this
+	// channel or the Producer will deadlock when the channel is full. Alternatively,
+	// you can set Producer.Return.Errors in your config to false, which prevents
+	// errors to be returned.
+	Errors() <-chan *ProducerError
+}
+
+// transactionManager keeps the state necessary to ensure idempotent production
+type transactionManager struct {
+	producerID      int64
+	producerEpoch   int16
+	sequenceNumbers map[string]int32
+	mutex           sync.Mutex
+}
+
+const (
+	noProducerID    = -1
+	noProducerEpoch = -1
+)
+
+func (t *transactionManager) getAndIncrementSequenceNumber(topic string, partition int32) int32 {
+	key := fmt.Sprintf("%s-%d", topic, partition)
+	t.mutex.Lock()
+	defer t.mutex.Unlock()
+	sequence := t.sequenceNumbers[key]
+	t.sequenceNumbers[key] = sequence + 1
+	return sequence
+}
+
+func newTransactionManager(conf *Config, client Client) (*transactionManager, error) {
+	txnmgr := &transactionManager{
+		producerID:    noProducerID,
+		producerEpoch: noProducerEpoch,
+	}
+
+	if conf.Producer.Idempotent {
+		initProducerIDResponse, err := client.InitProducerID()
+		if err != nil {
+			return nil, err
+		}
+		txnmgr.producerID = initProducerIDResponse.ProducerID
+		txnmgr.producerEpoch = initProducerIDResponse.ProducerEpoch
+		txnmgr.sequenceNumbers = make(map[string]int32)
+		txnmgr.mutex = sync.Mutex{}
+
+		Logger.Printf("Obtained a ProducerId: %d and ProducerEpoch: %d\n", txnmgr.producerID, txnmgr.producerEpoch)
+	}
+
+	return txnmgr, nil
+}
+
+type asyncProducer struct {
+	client Client
+	conf   *Config
+
+	errors                    chan *ProducerError
+	input, successes, retries chan *ProducerMessage
+	inFlight                  sync.WaitGroup
+
+	brokers    map[*Broker]*brokerProducer
+	brokerRefs map[*brokerProducer]int
+	brokerLock sync.Mutex
+
+	txnmgr *transactionManager
+}
+
+// NewAsyncProducer creates a new AsyncProducer using the given broker addresses and configuration.
+func NewAsyncProducer(addrs []string, conf *Config) (AsyncProducer, error) {
+	client, err := NewClient(addrs, conf)
+	if err != nil {
+		return nil, err
+	}
+	return newAsyncProducer(client)
+}
+
+// NewAsyncProducerFromClient creates a new Producer using the given client. It is still
+// necessary to call Close() on the underlying client when shutting down this producer.
+func NewAsyncProducerFromClient(client Client) (AsyncProducer, error) {
+	// For clients passed in by the client, ensure we don't
+	// call Close() on it.
+	cli := &nopCloserClient{client}
+	return newAsyncProducer(cli)
+}
+
+func newAsyncProducer(client Client) (AsyncProducer, error) {
+	// Check that we are not dealing with a closed Client before processing any other arguments
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	txnmgr, err := newTransactionManager(client.Config(), client)
+	if err != nil {
+		return nil, err
+	}
+
+	p := &asyncProducer{
+		client:     client,
+		conf:       client.Config(),
+		errors:     make(chan *ProducerError),
+		input:      make(chan *ProducerMessage),
+		successes:  make(chan *ProducerMessage),
+		retries:    make(chan *ProducerMessage),
+		brokers:    make(map[*Broker]*brokerProducer),
+		brokerRefs: make(map[*brokerProducer]int),
+		txnmgr:     txnmgr,
+	}
+
+	// launch our singleton dispatchers
+	go withRecover(p.dispatcher)
+	go withRecover(p.retryHandler)
+
+	return p, nil
+}
+
+type flagSet int8
+
+const (
+	syn      flagSet = 1 << iota // first message from partitionProducer to brokerProducer
+	fin                          // final message from partitionProducer to brokerProducer and back
+	shutdown                     // start the shutdown process
+)
+
+// ProducerMessage is the collection of elements passed to the Producer in order to send a message.
+type ProducerMessage struct {
+	Topic string // The Kafka topic for this message.
+	// The partitioning key for this message. Pre-existing Encoders include
+	// StringEncoder and ByteEncoder.
+	Key Encoder
+	// The actual message to store in Kafka. Pre-existing Encoders include
+	// StringEncoder and ByteEncoder.
+	Value Encoder
+
+	// The headers are key-value pairs that are transparently passed
+	// by Kafka between producers and consumers.
+	Headers []RecordHeader
+
+	// This field is used to hold arbitrary data you wish to include so it
+	// will be available when receiving on the Successes and Errors channels.
+	// Sarama completely ignores this field and is only to be used for
+	// pass-through data.
+	Metadata interface{}
+
+	// Below this point are filled in by the producer as the message is processed
+
+	// Offset is the offset of the message stored on the broker. This is only
+	// guaranteed to be defined if the message was successfully delivered and
+	// RequiredAcks is not NoResponse.
+	Offset int64
+	// Partition is the partition that the message was sent to. This is only
+	// guaranteed to be defined if the message was successfully delivered.
+	Partition int32
+	// Timestamp can vary in behaviour depending on broker configuration, being
+	// in either one of the CreateTime or LogAppendTime modes (default CreateTime),
+	// and requiring version at least 0.10.0.
+	//
+	// When configured to CreateTime, the timestamp is specified by the producer
+	// either by explicitly setting this field, or when the message is added
+	// to a produce set.
+	//
+	// When configured to LogAppendTime, the timestamp assigned to the message
+	// by the broker. This is only guaranteed to be defined if the message was
+	// successfully delivered and RequiredAcks is not NoResponse.
+	Timestamp time.Time
+
+	retries        int
+	flags          flagSet
+	expectation    chan *ProducerError
+	sequenceNumber int32
+}
+
+const producerMessageOverhead = 26 // the metadata overhead of CRC, flags, etc.
+
+func (m *ProducerMessage) byteSize(version int) int {
+	var size int
+	if version >= 2 {
+		size = maximumRecordOverhead
+		for _, h := range m.Headers {
+			size += len(h.Key) + len(h.Value) + 2*binary.MaxVarintLen32
+		}
+	} else {
+		size = producerMessageOverhead
+	}
+	if m.Key != nil {
+		size += m.Key.Length()
+	}
+	if m.Value != nil {
+		size += m.Value.Length()
+	}
+	return size
+}
+
+func (m *ProducerMessage) clear() {
+	m.flags = 0
+	m.retries = 0
+}
+
+// ProducerError is the type of error generated when the producer fails to deliver a message.
+// It contains the original ProducerMessage as well as the actual error value.
+type ProducerError struct {
+	Msg *ProducerMessage
+	Err error
+}
+
+func (pe ProducerError) Error() string {
+	return fmt.Sprintf("kafka: Failed to produce message to topic %s: %s", pe.Msg.Topic, pe.Err)
+}
+
+// ProducerErrors is a type that wraps a batch of "ProducerError"s and implements the Error interface.
+// It can be returned from the Producer's Close method to avoid the need to manually drain the Errors channel
+// when closing a producer.
+type ProducerErrors []*ProducerError
+
+func (pe ProducerErrors) Error() string {
+	return fmt.Sprintf("kafka: Failed to deliver %d messages.", len(pe))
+}
+
+func (p *asyncProducer) Errors() <-chan *ProducerError {
+	return p.errors
+}
+
+func (p *asyncProducer) Successes() <-chan *ProducerMessage {
+	return p.successes
+}
+
+func (p *asyncProducer) Input() chan<- *ProducerMessage {
+	return p.input
+}
+
+func (p *asyncProducer) Close() error {
+	p.AsyncClose()
+
+	if p.conf.Producer.Return.Successes {
+		go withRecover(func() {
+			for range p.successes {
+			}
+		})
+	}
+
+	var errors ProducerErrors
+	if p.conf.Producer.Return.Errors {
+		for event := range p.errors {
+			errors = append(errors, event)
+		}
+	} else {
+		<-p.errors
+	}
+
+	if len(errors) > 0 {
+		return errors
+	}
+	return nil
+}
+
+func (p *asyncProducer) AsyncClose() {
+	go withRecover(p.shutdown)
+}
+
+// singleton
+// dispatches messages by topic
+func (p *asyncProducer) dispatcher() {
+	handlers := make(map[string]chan<- *ProducerMessage)
+	shuttingDown := false
+
+	for msg := range p.input {
+		if msg == nil {
+			Logger.Println("Something tried to send a nil message, it was ignored.")
+			continue
+		}
+
+		if msg.flags&shutdown != 0 {
+			shuttingDown = true
+			p.inFlight.Done()
+			continue
+		} else if msg.retries == 0 {
+			if shuttingDown {
+				// we can't just call returnError here because that decrements the wait group,
+				// which hasn't been incremented yet for this message, and shouldn't be
+				pErr := &ProducerError{Msg: msg, Err: ErrShuttingDown}
+				if p.conf.Producer.Return.Errors {
+					p.errors <- pErr
+				} else {
+					Logger.Println(pErr)
+				}
+				continue
+			}
+			p.inFlight.Add(1)
+		}
+
+		version := 1
+		if p.conf.Version.IsAtLeast(V0_11_0_0) {
+			version = 2
+		} else if msg.Headers != nil {
+			p.returnError(msg, ConfigurationError("Producing headers requires Kafka at least v0.11"))
+			continue
+		}
+		if msg.byteSize(version) > p.conf.Producer.MaxMessageBytes {
+			p.returnError(msg, ErrMessageSizeTooLarge)
+			continue
+		}
+
+		handler := handlers[msg.Topic]
+		if handler == nil {
+			handler = p.newTopicProducer(msg.Topic)
+			handlers[msg.Topic] = handler
+		}
+
+		handler <- msg
+	}
+
+	for _, handler := range handlers {
+		close(handler)
+	}
+}
+
+// one per topic
+// partitions messages, then dispatches them by partition
+type topicProducer struct {
+	parent *asyncProducer
+	topic  string
+	input  <-chan *ProducerMessage
+
+	breaker     *breaker.Breaker
+	handlers    map[int32]chan<- *ProducerMessage
+	partitioner Partitioner
+}
+
+func (p *asyncProducer) newTopicProducer(topic string) chan<- *ProducerMessage {
+	input := make(chan *ProducerMessage, p.conf.ChannelBufferSize)
+	tp := &topicProducer{
+		parent:      p,
+		topic:       topic,
+		input:       input,
+		breaker:     breaker.New(3, 1, 10*time.Second),
+		handlers:    make(map[int32]chan<- *ProducerMessage),
+		partitioner: p.conf.Producer.Partitioner(topic),
+	}
+	go withRecover(tp.dispatch)
+	return input
+}
+
+func (tp *topicProducer) dispatch() {
+	for msg := range tp.input {
+		if msg.retries == 0 {
+			if err := tp.partitionMessage(msg); err != nil {
+				tp.parent.returnError(msg, err)
+				continue
+			}
+		}
+		// All messages being retried (sent or not) have already had their retry count updated
+		if tp.parent.conf.Producer.Idempotent && msg.retries == 0 {
+			msg.sequenceNumber = tp.parent.txnmgr.getAndIncrementSequenceNumber(msg.Topic, msg.Partition)
+		}
+
+		handler := tp.handlers[msg.Partition]
+		if handler == nil {
+			handler = tp.parent.newPartitionProducer(msg.Topic, msg.Partition)
+			tp.handlers[msg.Partition] = handler
+		}
+
+		handler <- msg
+	}
+
+	for _, handler := range tp.handlers {
+		close(handler)
+	}
+}
+
+func (tp *topicProducer) partitionMessage(msg *ProducerMessage) error {
+	var partitions []int32
+
+	err := tp.breaker.Run(func() (err error) {
+		var requiresConsistency = false
+		if ep, ok := tp.partitioner.(DynamicConsistencyPartitioner); ok {
+			requiresConsistency = ep.MessageRequiresConsistency(msg)
+		} else {
+			requiresConsistency = tp.partitioner.RequiresConsistency()
+		}
+
+		if requiresConsistency {
+			partitions, err = tp.parent.client.Partitions(msg.Topic)
+		} else {
+			partitions, err = tp.parent.client.WritablePartitions(msg.Topic)
+		}
+		return
+	})
+
+	if err != nil {
+		return err
+	}
+
+	numPartitions := int32(len(partitions))
+
+	if numPartitions == 0 {
+		return ErrLeaderNotAvailable
+	}
+
+	choice, err := tp.partitioner.Partition(msg, numPartitions)
+
+	if err != nil {
+		return err
+	} else if choice < 0 || choice >= numPartitions {
+		return ErrInvalidPartition
+	}
+
+	msg.Partition = partitions[choice]
+
+	return nil
+}
+
+// one per partition per topic
+// dispatches messages to the appropriate broker
+// also responsible for maintaining message order during retries
+type partitionProducer struct {
+	parent    *asyncProducer
+	topic     string
+	partition int32
+	input     <-chan *ProducerMessage
+
+	leader         *Broker
+	breaker        *breaker.Breaker
+	brokerProducer *brokerProducer
+
+	// highWatermark tracks the "current" retry level, which is the only one where we actually let messages through,
+	// all other messages get buffered in retryState[msg.retries].buf to preserve ordering
+	// retryState[msg.retries].expectChaser simply tracks whether we've seen a fin message for a given level (and
+	// therefore whether our buffer is complete and safe to flush)
+	highWatermark int
+	retryState    []partitionRetryState
+}
+
+type partitionRetryState struct {
+	buf          []*ProducerMessage
+	expectChaser bool
+}
+
+func (p *asyncProducer) newPartitionProducer(topic string, partition int32) chan<- *ProducerMessage {
+	input := make(chan *ProducerMessage, p.conf.ChannelBufferSize)
+	pp := &partitionProducer{
+		parent:    p,
+		topic:     topic,
+		partition: partition,
+		input:     input,
+
+		breaker:    breaker.New(3, 1, 10*time.Second),
+		retryState: make([]partitionRetryState, p.conf.Producer.Retry.Max+1),
+	}
+	go withRecover(pp.dispatch)
+	return input
+}
+
+func (pp *partitionProducer) backoff(retries int) {
+	var backoff time.Duration
+	if pp.parent.conf.Producer.Retry.BackoffFunc != nil {
+		maxRetries := pp.parent.conf.Producer.Retry.Max
+		backoff = pp.parent.conf.Producer.Retry.BackoffFunc(retries, maxRetries)
+	} else {
+		backoff = pp.parent.conf.Producer.Retry.Backoff
+	}
+	if backoff > 0 {
+		time.Sleep(backoff)
+	}
+}
+
+func (pp *partitionProducer) dispatch() {
+	// try to prefetch the leader; if this doesn't work, we'll do a proper call to `updateLeader`
+	// on the first message
+	pp.leader, _ = pp.parent.client.Leader(pp.topic, pp.partition)
+	if pp.leader != nil {
+		pp.brokerProducer = pp.parent.getBrokerProducer(pp.leader)
+		pp.parent.inFlight.Add(1) // we're generating a syn message; track it so we don't shut down while it's still inflight
+		pp.brokerProducer.input <- &ProducerMessage{Topic: pp.topic, Partition: pp.partition, flags: syn}
+	}
+
+	defer func() {
+		if pp.brokerProducer != nil {
+			pp.parent.unrefBrokerProducer(pp.leader, pp.brokerProducer)
+		}
+	}()
+
+	for msg := range pp.input {
+		if pp.brokerProducer != nil && pp.brokerProducer.abandoned != nil {
+			select {
+			case <-pp.brokerProducer.abandoned:
+				// a message on the abandoned channel means that our current broker selection is out of date
+				Logger.Printf("producer/leader/%s/%d abandoning broker %d\n", pp.topic, pp.partition, pp.leader.ID())
+				pp.parent.unrefBrokerProducer(pp.leader, pp.brokerProducer)
+				pp.brokerProducer = nil
+				time.Sleep(pp.parent.conf.Producer.Retry.Backoff)
+			default:
+				// producer connection is still open.
+			}
+		}
+
+		if msg.retries > pp.highWatermark {
+			// a new, higher, retry level; handle it and then back off
+			pp.newHighWatermark(msg.retries)
+			pp.backoff(msg.retries)
+		} else if pp.highWatermark > 0 {
+			// we are retrying something (else highWatermark would be 0) but this message is not a *new* retry level
+			if msg.retries < pp.highWatermark {
+				// in fact this message is not even the current retry level, so buffer it for now (unless it's a just a fin)
+				if msg.flags&fin == fin {
+					pp.retryState[msg.retries].expectChaser = false
+					pp.parent.inFlight.Done() // this fin is now handled and will be garbage collected
+				} else {
+					pp.retryState[msg.retries].buf = append(pp.retryState[msg.retries].buf, msg)
+				}
+				continue
+			} else if msg.flags&fin == fin {
+				// this message is of the current retry level (msg.retries == highWatermark) and the fin flag is set,
+				// meaning this retry level is done and we can go down (at least) one level and flush that
+				pp.retryState[pp.highWatermark].expectChaser = false
+				pp.flushRetryBuffers()
+				pp.parent.inFlight.Done() // this fin is now handled and will be garbage collected
+				continue
+			}
+		}
+
+		// if we made it this far then the current msg contains real data, and can be sent to the next goroutine
+		// without breaking any of our ordering guarantees
+
+		if pp.brokerProducer == nil {
+			if err := pp.updateLeader(); err != nil {
+				pp.parent.returnError(msg, err)
+				pp.backoff(msg.retries)
+				continue
+			}
+			Logger.Printf("producer/leader/%s/%d selected broker %d\n", pp.topic, pp.partition, pp.leader.ID())
+		}
+
+		pp.brokerProducer.input <- msg
+	}
+}
+
+func (pp *partitionProducer) newHighWatermark(hwm int) {
+	Logger.Printf("producer/leader/%s/%d state change to [retrying-%d]\n", pp.topic, pp.partition, hwm)
+	pp.highWatermark = hwm
+
+	// send off a fin so that we know when everything "in between" has made it
+	// back to us and we can safely flush the backlog (otherwise we risk re-ordering messages)
+	pp.retryState[pp.highWatermark].expectChaser = true
+	pp.parent.inFlight.Add(1) // we're generating a fin message; track it so we don't shut down while it's still inflight
+	pp.brokerProducer.input <- &ProducerMessage{Topic: pp.topic, Partition: pp.partition, flags: fin, retries: pp.highWatermark - 1}
+
+	// a new HWM means that our current broker selection is out of date
+	Logger.Printf("producer/leader/%s/%d abandoning broker %d\n", pp.topic, pp.partition, pp.leader.ID())
+	pp.parent.unrefBrokerProducer(pp.leader, pp.brokerProducer)
+	pp.brokerProducer = nil
+}
+
+func (pp *partitionProducer) flushRetryBuffers() {
+	Logger.Printf("producer/leader/%s/%d state change to [flushing-%d]\n", pp.topic, pp.partition, pp.highWatermark)
+	for {
+		pp.highWatermark--
+
+		if pp.brokerProducer == nil {
+			if err := pp.updateLeader(); err != nil {
+				pp.parent.returnErrors(pp.retryState[pp.highWatermark].buf, err)
+				goto flushDone
+			}
+			Logger.Printf("producer/leader/%s/%d selected broker %d\n", pp.topic, pp.partition, pp.leader.ID())
+		}
+
+		for _, msg := range pp.retryState[pp.highWatermark].buf {
+			pp.brokerProducer.input <- msg
+		}
+
+	flushDone:
+		pp.retryState[pp.highWatermark].buf = nil
+		if pp.retryState[pp.highWatermark].expectChaser {
+			Logger.Printf("producer/leader/%s/%d state change to [retrying-%d]\n", pp.topic, pp.partition, pp.highWatermark)
+			break
+		} else if pp.highWatermark == 0 {
+			Logger.Printf("producer/leader/%s/%d state change to [normal]\n", pp.topic, pp.partition)
+			break
+		}
+	}
+}
+
+func (pp *partitionProducer) updateLeader() error {
+	return pp.breaker.Run(func() (err error) {
+		if err = pp.parent.client.RefreshMetadata(pp.topic); err != nil {
+			return err
+		}
+
+		if pp.leader, err = pp.parent.client.Leader(pp.topic, pp.partition); err != nil {
+			return err
+		}
+
+		pp.brokerProducer = pp.parent.getBrokerProducer(pp.leader)
+		pp.parent.inFlight.Add(1) // we're generating a syn message; track it so we don't shut down while it's still inflight
+		pp.brokerProducer.input <- &ProducerMessage{Topic: pp.topic, Partition: pp.partition, flags: syn}
+
+		return nil
+	})
+}
+
+// one per broker; also constructs an associated flusher
+func (p *asyncProducer) newBrokerProducer(broker *Broker) *brokerProducer {
+	var (
+		input     = make(chan *ProducerMessage)
+		bridge    = make(chan *produceSet)
+		responses = make(chan *brokerProducerResponse)
+	)
+
+	bp := &brokerProducer{
+		parent:         p,
+		broker:         broker,
+		input:          input,
+		output:         bridge,
+		responses:      responses,
+		stopchan:       make(chan struct{}),
+		buffer:         newProduceSet(p),
+		currentRetries: make(map[string]map[int32]error),
+	}
+	go withRecover(bp.run)
+
+	// minimal bridge to make the network response `select`able
+	go withRecover(func() {
+		for set := range bridge {
+			request := set.buildRequest()
+
+			response, err := broker.Produce(request)
+
+			responses <- &brokerProducerResponse{
+				set: set,
+				err: err,
+				res: response,
+			}
+		}
+		close(responses)
+	})
+
+	if p.conf.Producer.Retry.Max <= 0 {
+		bp.abandoned = make(chan struct{})
+	}
+
+	return bp
+}
+
+type brokerProducerResponse struct {
+	set *produceSet
+	err error
+	res *ProduceResponse
+}
+
+// groups messages together into appropriately-sized batches for sending to the broker
+// handles state related to retries etc
+type brokerProducer struct {
+	parent *asyncProducer
+	broker *Broker
+
+	input     chan *ProducerMessage
+	output    chan<- *produceSet
+	responses <-chan *brokerProducerResponse
+	abandoned chan struct{}
+	stopchan  chan struct{}
+
+	buffer     *produceSet
+	timer      <-chan time.Time
+	timerFired bool
+
+	closing        error
+	currentRetries map[string]map[int32]error
+}
+
+func (bp *brokerProducer) run() {
+	var output chan<- *produceSet
+	Logger.Printf("producer/broker/%d starting up\n", bp.broker.ID())
+
+	for {
+		select {
+		case msg, ok := <-bp.input:
+			if !ok {
+				Logger.Printf("producer/broker/%d input chan closed\n", bp.broker.ID())
+				bp.shutdown()
+				return
+			}
+
+			if msg == nil {
+				continue
+			}
+
+			if msg.flags&syn == syn {
+				Logger.Printf("producer/broker/%d state change to [open] on %s/%d\n",
+					bp.broker.ID(), msg.Topic, msg.Partition)
+				if bp.currentRetries[msg.Topic] == nil {
+					bp.currentRetries[msg.Topic] = make(map[int32]error)
+				}
+				bp.currentRetries[msg.Topic][msg.Partition] = nil
+				bp.parent.inFlight.Done()
+				continue
+			}
+
+			if reason := bp.needsRetry(msg); reason != nil {
+				bp.parent.retryMessage(msg, reason)
+
+				if bp.closing == nil && msg.flags&fin == fin {
+					// we were retrying this partition but we can start processing again
+					delete(bp.currentRetries[msg.Topic], msg.Partition)
+					Logger.Printf("producer/broker/%d state change to [closed] on %s/%d\n",
+						bp.broker.ID(), msg.Topic, msg.Partition)
+				}
+
+				continue
+			}
+
+			if bp.buffer.wouldOverflow(msg) {
+				if err := bp.waitForSpace(msg); err != nil {
+					bp.parent.retryMessage(msg, err)
+					continue
+				}
+			}
+
+			if err := bp.buffer.add(msg); err != nil {
+				bp.parent.returnError(msg, err)
+				continue
+			}
+
+			if bp.parent.conf.Producer.Flush.Frequency > 0 && bp.timer == nil {
+				bp.timer = time.After(bp.parent.conf.Producer.Flush.Frequency)
+			}
+		case <-bp.timer:
+			bp.timerFired = true
+		case output <- bp.buffer:
+			bp.rollOver()
+		case response, ok := <-bp.responses:
+			if ok {
+				bp.handleResponse(response)
+			}
+		case <-bp.stopchan:
+			Logger.Printf(
+				"producer/broker/%d run loop asked to stop\n", bp.broker.ID())
+			return
+		}
+
+		if bp.timerFired || bp.buffer.readyToFlush() {
+			output = bp.output
+		} else {
+			output = nil
+		}
+	}
+}
+
+func (bp *brokerProducer) shutdown() {
+	for !bp.buffer.empty() {
+		select {
+		case response := <-bp.responses:
+			bp.handleResponse(response)
+		case bp.output <- bp.buffer:
+			bp.rollOver()
+		}
+	}
+	close(bp.output)
+	for response := range bp.responses {
+		bp.handleResponse(response)
+	}
+	close(bp.stopchan)
+	Logger.Printf("producer/broker/%d shut down\n", bp.broker.ID())
+}
+
+func (bp *brokerProducer) needsRetry(msg *ProducerMessage) error {
+	if bp.closing != nil {
+		return bp.closing
+	}
+
+	return bp.currentRetries[msg.Topic][msg.Partition]
+}
+
+func (bp *brokerProducer) waitForSpace(msg *ProducerMessage) error {
+	Logger.Printf("producer/broker/%d maximum request accumulated, waiting for space\n", bp.broker.ID())
+
+	for {
+		select {
+		case response := <-bp.responses:
+			bp.handleResponse(response)
+			// handling a response can change our state, so re-check some things
+			if reason := bp.needsRetry(msg); reason != nil {
+				return reason
+			} else if !bp.buffer.wouldOverflow(msg) {
+				return nil
+			}
+		case bp.output <- bp.buffer:
+			bp.rollOver()
+			return nil
+		}
+	}
+}
+
+func (bp *brokerProducer) rollOver() {
+	bp.timer = nil
+	bp.timerFired = false
+	bp.buffer = newProduceSet(bp.parent)
+}
+
+func (bp *brokerProducer) handleResponse(response *brokerProducerResponse) {
+	if response.err != nil {
+		bp.handleError(response.set, response.err)
+	} else {
+		bp.handleSuccess(response.set, response.res)
+	}
+
+	if bp.buffer.empty() {
+		bp.rollOver() // this can happen if the response invalidated our buffer
+	}
+}
+
+func (bp *brokerProducer) handleSuccess(sent *produceSet, response *ProduceResponse) {
+	// we iterate through the blocks in the request set, not the response, so that we notice
+	// if the response is missing a block completely
+	var retryTopics []string
+	sent.eachPartition(func(topic string, partition int32, pSet *partitionSet) {
+		if response == nil {
+			// this only happens when RequiredAcks is NoResponse, so we have to assume success
+			bp.parent.returnSuccesses(pSet.msgs)
+			return
+		}
+
+		block := response.GetBlock(topic, partition)
+		if block == nil {
+			bp.parent.returnErrors(pSet.msgs, ErrIncompleteResponse)
+			return
+		}
+
+		switch block.Err {
+		// Success
+		case ErrNoError:
+			if bp.parent.conf.Version.IsAtLeast(V0_10_0_0) && !block.Timestamp.IsZero() {
+				for _, msg := range pSet.msgs {
+					msg.Timestamp = block.Timestamp
+				}
+			}
+			for i, msg := range pSet.msgs {
+				msg.Offset = block.Offset + int64(i)
+			}
+			bp.parent.returnSuccesses(pSet.msgs)
+		// Duplicate
+		case ErrDuplicateSequenceNumber:
+			bp.parent.returnSuccesses(pSet.msgs)
+		// Retriable errors
+		case ErrInvalidMessage, ErrUnknownTopicOrPartition, ErrLeaderNotAvailable, ErrNotLeaderForPartition,
+			ErrRequestTimedOut, ErrNotEnoughReplicas, ErrNotEnoughReplicasAfterAppend:
+			if bp.parent.conf.Producer.Retry.Max <= 0 {
+				bp.parent.abandonBrokerConnection(bp.broker)
+				bp.parent.returnErrors(pSet.msgs, block.Err)
+			} else {
+				retryTopics = append(retryTopics, topic)
+			}
+		// Other non-retriable errors
+		default:
+			if bp.parent.conf.Producer.Retry.Max <= 0 {
+				bp.parent.abandonBrokerConnection(bp.broker)
+			}
+			bp.parent.returnErrors(pSet.msgs, block.Err)
+		}
+	})
+
+	if len(retryTopics) > 0 {
+		if bp.parent.conf.Producer.Idempotent {
+			err := bp.parent.client.RefreshMetadata(retryTopics...)
+			if err != nil {
+				Logger.Printf("Failed refreshing metadata because of %v\n", err)
+			}
+		}
+
+		sent.eachPartition(func(topic string, partition int32, pSet *partitionSet) {
+			block := response.GetBlock(topic, partition)
+			if block == nil {
+				// handled in the previous "eachPartition" loop
+				return
+			}
+
+			switch block.Err {
+			case ErrInvalidMessage, ErrUnknownTopicOrPartition, ErrLeaderNotAvailable, ErrNotLeaderForPartition,
+				ErrRequestTimedOut, ErrNotEnoughReplicas, ErrNotEnoughReplicasAfterAppend:
+				Logger.Printf("producer/broker/%d state change to [retrying] on %s/%d because %v\n",
+					bp.broker.ID(), topic, partition, block.Err)
+				if bp.currentRetries[topic] == nil {
+					bp.currentRetries[topic] = make(map[int32]error)
+				}
+				bp.currentRetries[topic][partition] = block.Err
+				if bp.parent.conf.Producer.Idempotent {
+					go bp.parent.retryBatch(topic, partition, pSet, block.Err)
+				} else {
+					bp.parent.retryMessages(pSet.msgs, block.Err)
+				}
+				// dropping the following messages has the side effect of incrementing their retry count
+				bp.parent.retryMessages(bp.buffer.dropPartition(topic, partition), block.Err)
+			}
+		})
+	}
+}
+
+func (p *asyncProducer) retryBatch(topic string, partition int32, pSet *partitionSet, kerr KError) {
+	Logger.Printf("Retrying batch for %v-%d because of %s\n", topic, partition, kerr)
+	produceSet := newProduceSet(p)
+	produceSet.msgs[topic] = make(map[int32]*partitionSet)
+	produceSet.msgs[topic][partition] = pSet
+	produceSet.bufferBytes += pSet.bufferBytes
+	produceSet.bufferCount += len(pSet.msgs)
+	for _, msg := range pSet.msgs {
+		if msg.retries >= p.conf.Producer.Retry.Max {
+			p.returnError(msg, kerr)
+			return
+		}
+		msg.retries++
+	}
+
+	// it's expected that a metadata refresh has been requested prior to calling retryBatch
+	leader, err := p.client.Leader(topic, partition)
+	if err != nil {
+		Logger.Printf("Failed retrying batch for %v-%d because of %v while looking up for new leader\n", topic, partition, err)
+		for _, msg := range pSet.msgs {
+			p.returnError(msg, kerr)
+		}
+		return
+	}
+	bp := p.getBrokerProducer(leader)
+	bp.output <- produceSet
+}
+
+func (bp *brokerProducer) handleError(sent *produceSet, err error) {
+	switch err.(type) {
+	case PacketEncodingError:
+		sent.eachPartition(func(topic string, partition int32, pSet *partitionSet) {
+			bp.parent.returnErrors(pSet.msgs, err)
+		})
+	default:
+		Logger.Printf("producer/broker/%d state change to [closing] because %s\n", bp.broker.ID(), err)
+		bp.parent.abandonBrokerConnection(bp.broker)
+		_ = bp.broker.Close()
+		bp.closing = err
+		sent.eachPartition(func(topic string, partition int32, pSet *partitionSet) {
+			bp.parent.retryMessages(pSet.msgs, err)
+		})
+		bp.buffer.eachPartition(func(topic string, partition int32, pSet *partitionSet) {
+			bp.parent.retryMessages(pSet.msgs, err)
+		})
+		bp.rollOver()
+	}
+}
+
+// singleton
+// effectively a "bridge" between the flushers and the dispatcher in order to avoid deadlock
+// based on https://godoc.org/github.com/eapache/channels#InfiniteChannel
+func (p *asyncProducer) retryHandler() {
+	var msg *ProducerMessage
+	buf := queue.New()
+
+	for {
+		if buf.Length() == 0 {
+			msg = <-p.retries
+		} else {
+			select {
+			case msg = <-p.retries:
+			case p.input <- buf.Peek().(*ProducerMessage):
+				buf.Remove()
+				continue
+			}
+		}
+
+		if msg == nil {
+			return
+		}
+
+		buf.Add(msg)
+	}
+}
+
+// utility functions
+
+func (p *asyncProducer) shutdown() {
+	Logger.Println("Producer shutting down.")
+	p.inFlight.Add(1)
+	p.input <- &ProducerMessage{flags: shutdown}
+
+	p.inFlight.Wait()
+
+	err := p.client.Close()
+	if err != nil {
+		Logger.Println("producer/shutdown failed to close the embedded client:", err)
+	}
+
+	close(p.input)
+	close(p.retries)
+	close(p.errors)
+	close(p.successes)
+}
+
+func (p *asyncProducer) returnError(msg *ProducerMessage, err error) {
+	msg.clear()
+	pErr := &ProducerError{Msg: msg, Err: err}
+	if p.conf.Producer.Return.Errors {
+		p.errors <- pErr
+	} else {
+		Logger.Println(pErr)
+	}
+	p.inFlight.Done()
+}
+
+func (p *asyncProducer) returnErrors(batch []*ProducerMessage, err error) {
+	for _, msg := range batch {
+		p.returnError(msg, err)
+	}
+}
+
+func (p *asyncProducer) returnSuccesses(batch []*ProducerMessage) {
+	for _, msg := range batch {
+		if p.conf.Producer.Return.Successes {
+			msg.clear()
+			p.successes <- msg
+		}
+		p.inFlight.Done()
+	}
+}
+
+func (p *asyncProducer) retryMessage(msg *ProducerMessage, err error) {
+	if msg.retries >= p.conf.Producer.Retry.Max {
+		p.returnError(msg, err)
+	} else {
+		msg.retries++
+		p.retries <- msg
+	}
+}
+
+func (p *asyncProducer) retryMessages(batch []*ProducerMessage, err error) {
+	for _, msg := range batch {
+		p.retryMessage(msg, err)
+	}
+}
+
+func (p *asyncProducer) getBrokerProducer(broker *Broker) *brokerProducer {
+	p.brokerLock.Lock()
+	defer p.brokerLock.Unlock()
+
+	bp := p.brokers[broker]
+
+	if bp == nil {
+		bp = p.newBrokerProducer(broker)
+		p.brokers[broker] = bp
+		p.brokerRefs[bp] = 0
+	}
+
+	p.brokerRefs[bp]++
+
+	return bp
+}
+
+func (p *asyncProducer) unrefBrokerProducer(broker *Broker, bp *brokerProducer) {
+	p.brokerLock.Lock()
+	defer p.brokerLock.Unlock()
+
+	p.brokerRefs[bp]--
+	if p.brokerRefs[bp] == 0 {
+		close(bp.input)
+		delete(p.brokerRefs, bp)
+
+		if p.brokers[broker] == bp {
+			delete(p.brokers, broker)
+		}
+	}
+}
+
+func (p *asyncProducer) abandonBrokerConnection(broker *Broker) {
+	p.brokerLock.Lock()
+	defer p.brokerLock.Unlock()
+
+	bc, ok := p.brokers[broker]
+	if ok && bc.abandoned != nil {
+		close(bc.abandoned)
+	}
+
+	delete(p.brokers, broker)
+}
diff --git a/vendor/github.com/Shopify/sarama/balance_strategy.go b/vendor/github.com/Shopify/sarama/balance_strategy.go
new file mode 100644
index 0000000..67c4d96
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/balance_strategy.go
@@ -0,0 +1,1053 @@
+package sarama
+
+import (
+	"container/heap"
+	"math"
+	"sort"
+	"strings"
+)
+
+const (
+	// RangeBalanceStrategyName identifies strategies that use the range partition assignment strategy
+	RangeBalanceStrategyName = "range"
+
+	// RoundRobinBalanceStrategyName identifies strategies that use the round-robin partition assignment strategy
+	RoundRobinBalanceStrategyName = "roundrobin"
+
+	// StickyBalanceStrategyName identifies strategies that use the sticky-partition assignment strategy
+	StickyBalanceStrategyName = "sticky"
+
+	defaultGeneration = -1
+)
+
+// BalanceStrategyPlan is the results of any BalanceStrategy.Plan attempt.
+// It contains an allocation of topic/partitions by memberID in the form of
+// a `memberID -> topic -> partitions` map.
+type BalanceStrategyPlan map[string]map[string][]int32
+
+// Add assigns a topic with a number partitions to a member.
+func (p BalanceStrategyPlan) Add(memberID, topic string, partitions ...int32) {
+	if len(partitions) == 0 {
+		return
+	}
+	if _, ok := p[memberID]; !ok {
+		p[memberID] = make(map[string][]int32, 1)
+	}
+	p[memberID][topic] = append(p[memberID][topic], partitions...)
+}
+
+// --------------------------------------------------------------------
+
+// BalanceStrategy is used to balance topics and partitions
+// across members of a consumer group
+type BalanceStrategy interface {
+	// Name uniquely identifies the strategy.
+	Name() string
+
+	// Plan accepts a map of `memberID -> metadata` and a map of `topic -> partitions`
+	// and returns a distribution plan.
+	Plan(members map[string]ConsumerGroupMemberMetadata, topics map[string][]int32) (BalanceStrategyPlan, error)
+}
+
+// --------------------------------------------------------------------
+
+// BalanceStrategyRange is the default and assigns partitions as ranges to consumer group members.
+// Example with one topic T with six partitions (0..5) and two members (M1, M2):
+//   M1: {T: [0, 1, 2]}
+//   M2: {T: [3, 4, 5]}
+var BalanceStrategyRange = &balanceStrategy{
+	name: RangeBalanceStrategyName,
+	coreFn: func(plan BalanceStrategyPlan, memberIDs []string, topic string, partitions []int32) {
+		step := float64(len(partitions)) / float64(len(memberIDs))
+
+		for i, memberID := range memberIDs {
+			pos := float64(i)
+			min := int(math.Floor(pos*step + 0.5))
+			max := int(math.Floor((pos+1)*step + 0.5))
+			plan.Add(memberID, topic, partitions[min:max]...)
+		}
+	},
+}
+
+// BalanceStrategyRoundRobin assigns partitions to members in alternating order.
+// Example with topic T with six partitions (0..5) and two members (M1, M2):
+//   M1: {T: [0, 2, 4]}
+//   M2: {T: [1, 3, 5]}
+var BalanceStrategyRoundRobin = &balanceStrategy{
+	name: RoundRobinBalanceStrategyName,
+	coreFn: func(plan BalanceStrategyPlan, memberIDs []string, topic string, partitions []int32) {
+		for i, part := range partitions {
+			memberID := memberIDs[i%len(memberIDs)]
+			plan.Add(memberID, topic, part)
+		}
+	},
+}
+
+// BalanceStrategySticky assigns partitions to members with an attempt to preserve earlier assignments
+// while maintain a balanced partition distribution.
+// Example with topic T with six partitions (0..5) and two members (M1, M2):
+//   M1: {T: [0, 2, 4]}
+//   M2: {T: [1, 3, 5]}
+//
+// On reassignment with an additional consumer, you might get an assignment plan like:
+//   M1: {T: [0, 2]}
+//   M2: {T: [1, 3]}
+//   M3: {T: [4, 5]}
+//
+var BalanceStrategySticky = &stickyBalanceStrategy{}
+
+// --------------------------------------------------------------------
+
+type balanceStrategy struct {
+	name   string
+	coreFn func(plan BalanceStrategyPlan, memberIDs []string, topic string, partitions []int32)
+}
+
+// Name implements BalanceStrategy.
+func (s *balanceStrategy) Name() string { return s.name }
+
+// Plan implements BalanceStrategy.
+func (s *balanceStrategy) Plan(members map[string]ConsumerGroupMemberMetadata, topics map[string][]int32) (BalanceStrategyPlan, error) {
+	// Build members by topic map
+	mbt := make(map[string][]string)
+	for memberID, meta := range members {
+		for _, topic := range meta.Topics {
+			mbt[topic] = append(mbt[topic], memberID)
+		}
+	}
+
+	// Sort members for each topic
+	for topic, memberIDs := range mbt {
+		sort.Sort(&balanceStrategySortable{
+			topic:     topic,
+			memberIDs: memberIDs,
+		})
+	}
+
+	// Assemble plan
+	plan := make(BalanceStrategyPlan, len(members))
+	for topic, memberIDs := range mbt {
+		s.coreFn(plan, memberIDs, topic, topics[topic])
+	}
+	return plan, nil
+}
+
+type balanceStrategySortable struct {
+	topic     string
+	memberIDs []string
+}
+
+func (p balanceStrategySortable) Len() int { return len(p.memberIDs) }
+func (p balanceStrategySortable) Swap(i, j int) {
+	p.memberIDs[i], p.memberIDs[j] = p.memberIDs[j], p.memberIDs[i]
+}
+func (p balanceStrategySortable) Less(i, j int) bool {
+	return balanceStrategyHashValue(p.topic, p.memberIDs[i]) < balanceStrategyHashValue(p.topic, p.memberIDs[j])
+}
+
+func balanceStrategyHashValue(vv ...string) uint32 {
+	h := uint32(2166136261)
+	for _, s := range vv {
+		for _, c := range s {
+			h ^= uint32(c)
+			h *= 16777619
+		}
+	}
+	return h
+}
+
+type stickyBalanceStrategy struct {
+	movements partitionMovements
+}
+
+// Name implements BalanceStrategy.
+func (s *stickyBalanceStrategy) Name() string { return StickyBalanceStrategyName }
+
+// Plan implements BalanceStrategy.
+func (s *stickyBalanceStrategy) Plan(members map[string]ConsumerGroupMemberMetadata, topics map[string][]int32) (BalanceStrategyPlan, error) {
+	// track partition movements during generation of the partition assignment plan
+	s.movements = partitionMovements{
+		Movements:                 make(map[topicPartitionAssignment]consumerPair),
+		PartitionMovementsByTopic: make(map[string]map[consumerPair]map[topicPartitionAssignment]bool),
+	}
+
+	// prepopulate the current assignment state from userdata on the consumer group members
+	currentAssignment, prevAssignment, err := prepopulateCurrentAssignments(members)
+	if err != nil {
+		return nil, err
+	}
+
+	// determine if we're dealing with a completely fresh assignment, or if there's existing assignment state
+	isFreshAssignment := false
+	if len(currentAssignment) == 0 {
+		isFreshAssignment = true
+	}
+
+	// create a mapping of all current topic partitions and the consumers that can be assigned to them
+	partition2AllPotentialConsumers := make(map[topicPartitionAssignment][]string)
+	for topic, partitions := range topics {
+		for _, partition := range partitions {
+			partition2AllPotentialConsumers[topicPartitionAssignment{Topic: topic, Partition: partition}] = []string{}
+		}
+	}
+
+	// create a mapping of all consumers to all potential topic partitions that can be assigned to them
+	// also, populate the mapping of partitions to potential consumers
+	consumer2AllPotentialPartitions := make(map[string][]topicPartitionAssignment, len(members))
+	for memberID, meta := range members {
+		consumer2AllPotentialPartitions[memberID] = make([]topicPartitionAssignment, 0)
+		for _, topicSubscription := range meta.Topics {
+			// only evaluate topic subscriptions that are present in the supplied topics map
+			if _, found := topics[topicSubscription]; found {
+				for _, partition := range topics[topicSubscription] {
+					topicPartition := topicPartitionAssignment{Topic: topicSubscription, Partition: partition}
+					consumer2AllPotentialPartitions[memberID] = append(consumer2AllPotentialPartitions[memberID], topicPartition)
+					partition2AllPotentialConsumers[topicPartition] = append(partition2AllPotentialConsumers[topicPartition], memberID)
+				}
+			}
+		}
+
+		// add this consumer to currentAssignment (with an empty topic partition assignment) if it does not already exist
+		if _, exists := currentAssignment[memberID]; !exists {
+			currentAssignment[memberID] = make([]topicPartitionAssignment, 0)
+		}
+	}
+
+	// create a mapping of each partition to its current consumer, where possible
+	currentPartitionConsumers := make(map[topicPartitionAssignment]string, len(currentAssignment))
+	unvisitedPartitions := make(map[topicPartitionAssignment]bool, len(partition2AllPotentialConsumers))
+	for partition := range partition2AllPotentialConsumers {
+		unvisitedPartitions[partition] = true
+	}
+	var unassignedPartitions []topicPartitionAssignment
+	for memberID, partitions := range currentAssignment {
+		var keepPartitions []topicPartitionAssignment
+		for _, partition := range partitions {
+			// If this partition no longer exists at all, likely due to the
+			// topic being deleted, we remove the partition from the member.
+			if _, exists := partition2AllPotentialConsumers[partition]; !exists {
+				continue
+			}
+			delete(unvisitedPartitions, partition)
+			currentPartitionConsumers[partition] = memberID
+
+			if !strsContains(members[memberID].Topics, partition.Topic) {
+				unassignedPartitions = append(unassignedPartitions, partition)
+				continue
+			}
+			keepPartitions = append(keepPartitions, partition)
+		}
+		currentAssignment[memberID] = keepPartitions
+	}
+	for unvisited := range unvisitedPartitions {
+		unassignedPartitions = append(unassignedPartitions, unvisited)
+	}
+
+	// sort the topic partitions in order of priority for reassignment
+	sortedPartitions := sortPartitions(currentAssignment, prevAssignment, isFreshAssignment, partition2AllPotentialConsumers, consumer2AllPotentialPartitions)
+
+	// at this point we have preserved all valid topic partition to consumer assignments and removed
+	// all invalid topic partitions and invalid consumers. Now we need to assign unassignedPartitions
+	// to consumers so that the topic partition assignments are as balanced as possible.
+
+	// an ascending sorted set of consumers based on how many topic partitions are already assigned to them
+	sortedCurrentSubscriptions := sortMemberIDsByPartitionAssignments(currentAssignment)
+	s.balance(currentAssignment, prevAssignment, sortedPartitions, unassignedPartitions, sortedCurrentSubscriptions, consumer2AllPotentialPartitions, partition2AllPotentialConsumers, currentPartitionConsumers)
+
+	// Assemble plan
+	plan := make(BalanceStrategyPlan, len(currentAssignment))
+	for memberID, assignments := range currentAssignment {
+		if len(assignments) == 0 {
+			plan[memberID] = make(map[string][]int32, 0)
+		} else {
+			for _, assignment := range assignments {
+				plan.Add(memberID, assignment.Topic, assignment.Partition)
+			}
+		}
+	}
+	return plan, nil
+}
+
+func strsContains(s []string, value string) bool {
+	for _, entry := range s {
+		if entry == value {
+			return true
+		}
+	}
+	return false
+}
+
+// Balance assignments across consumers for maximum fairness and stickiness.
+func (s *stickyBalanceStrategy) balance(currentAssignment map[string][]topicPartitionAssignment, prevAssignment map[topicPartitionAssignment]consumerGenerationPair, sortedPartitions []topicPartitionAssignment, unassignedPartitions []topicPartitionAssignment, sortedCurrentSubscriptions []string, consumer2AllPotentialPartitions map[string][]topicPartitionAssignment, partition2AllPotentialConsumers map[topicPartitionAssignment][]string, currentPartitionConsumer map[topicPartitionAssignment]string) {
+	initializing := false
+	if len(sortedCurrentSubscriptions) == 0 || len(currentAssignment[sortedCurrentSubscriptions[0]]) == 0 {
+		initializing = true
+	}
+
+	// assign all unassigned partitions
+	for _, partition := range unassignedPartitions {
+		// skip if there is no potential consumer for the partition
+		if len(partition2AllPotentialConsumers[partition]) == 0 {
+			continue
+		}
+		sortedCurrentSubscriptions = assignPartition(partition, sortedCurrentSubscriptions, currentAssignment, consumer2AllPotentialPartitions, currentPartitionConsumer)
+	}
+
+	// narrow down the reassignment scope to only those partitions that can actually be reassigned
+	for partition := range partition2AllPotentialConsumers {
+		if !canTopicPartitionParticipateInReassignment(partition, partition2AllPotentialConsumers) {
+			sortedPartitions = removeTopicPartitionFromMemberAssignments(sortedPartitions, partition)
+		}
+	}
+
+	// narrow down the reassignment scope to only those consumers that are subject to reassignment
+	fixedAssignments := make(map[string][]topicPartitionAssignment)
+	for memberID := range consumer2AllPotentialPartitions {
+		if !canConsumerParticipateInReassignment(memberID, currentAssignment, consumer2AllPotentialPartitions, partition2AllPotentialConsumers) {
+			fixedAssignments[memberID] = currentAssignment[memberID]
+			delete(currentAssignment, memberID)
+			sortedCurrentSubscriptions = sortMemberIDsByPartitionAssignments(currentAssignment)
+		}
+	}
+
+	// create a deep copy of the current assignment so we can revert to it if we do not get a more balanced assignment later
+	preBalanceAssignment := deepCopyAssignment(currentAssignment)
+	preBalancePartitionConsumers := make(map[topicPartitionAssignment]string, len(currentPartitionConsumer))
+	for k, v := range currentPartitionConsumer {
+		preBalancePartitionConsumers[k] = v
+	}
+
+	reassignmentPerformed := s.performReassignments(sortedPartitions, currentAssignment, prevAssignment, sortedCurrentSubscriptions, consumer2AllPotentialPartitions, partition2AllPotentialConsumers, currentPartitionConsumer)
+
+	// if we are not preserving existing assignments and we have made changes to the current assignment
+	// make sure we are getting a more balanced assignment; otherwise, revert to previous assignment
+	if !initializing && reassignmentPerformed && getBalanceScore(currentAssignment) >= getBalanceScore(preBalanceAssignment) {
+		currentAssignment = deepCopyAssignment(preBalanceAssignment)
+		currentPartitionConsumer = make(map[topicPartitionAssignment]string, len(preBalancePartitionConsumers))
+		for k, v := range preBalancePartitionConsumers {
+			currentPartitionConsumer[k] = v
+		}
+	}
+
+	// add the fixed assignments (those that could not change) back
+	for consumer, assignments := range fixedAssignments {
+		currentAssignment[consumer] = assignments
+	}
+}
+
+// Calculate the balance score of the given assignment, as the sum of assigned partitions size difference of all consumer pairs.
+// A perfectly balanced assignment (with all consumers getting the same number of partitions) has a balance score of 0.
+// Lower balance score indicates a more balanced assignment.
+func getBalanceScore(assignment map[string][]topicPartitionAssignment) int {
+	consumer2AssignmentSize := make(map[string]int, len(assignment))
+	for memberID, partitions := range assignment {
+		consumer2AssignmentSize[memberID] = len(partitions)
+	}
+
+	var score float64
+	for memberID, consumerAssignmentSize := range consumer2AssignmentSize {
+		delete(consumer2AssignmentSize, memberID)
+		for _, otherConsumerAssignmentSize := range consumer2AssignmentSize {
+			score += math.Abs(float64(consumerAssignmentSize - otherConsumerAssignmentSize))
+		}
+	}
+	return int(score)
+}
+
+// Determine whether the current assignment plan is balanced.
+func isBalanced(currentAssignment map[string][]topicPartitionAssignment, sortedCurrentSubscriptions []string, allSubscriptions map[string][]topicPartitionAssignment) bool {
+	sortedCurrentSubscriptions = sortMemberIDsByPartitionAssignments(currentAssignment)
+	min := len(currentAssignment[sortedCurrentSubscriptions[0]])
+	max := len(currentAssignment[sortedCurrentSubscriptions[len(sortedCurrentSubscriptions)-1]])
+	if min >= max-1 {
+		// if minimum and maximum numbers of partitions assigned to consumers differ by at most one return true
+		return true
+	}
+
+	// create a mapping from partitions to the consumer assigned to them
+	allPartitions := make(map[topicPartitionAssignment]string)
+	for memberID, partitions := range currentAssignment {
+		for _, partition := range partitions {
+			if _, exists := allPartitions[partition]; exists {
+				Logger.Printf("Topic %s Partition %d is assigned more than one consumer", partition.Topic, partition.Partition)
+			}
+			allPartitions[partition] = memberID
+		}
+	}
+
+	// for each consumer that does not have all the topic partitions it can get make sure none of the topic partitions it
+	// could but did not get cannot be moved to it (because that would break the balance)
+	for _, memberID := range sortedCurrentSubscriptions {
+		consumerPartitions := currentAssignment[memberID]
+		consumerPartitionCount := len(consumerPartitions)
+
+		// skip if this consumer already has all the topic partitions it can get
+		if consumerPartitionCount == len(allSubscriptions[memberID]) {
+			continue
+		}
+
+		// otherwise make sure it cannot get any more
+		potentialTopicPartitions := allSubscriptions[memberID]
+		for _, partition := range potentialTopicPartitions {
+			if !memberAssignmentsIncludeTopicPartition(currentAssignment[memberID], partition) {
+				otherConsumer := allPartitions[partition]
+				otherConsumerPartitionCount := len(currentAssignment[otherConsumer])
+				if consumerPartitionCount < otherConsumerPartitionCount {
+					return false
+				}
+			}
+		}
+	}
+	return true
+}
+
+// Reassign all topic partitions that need reassignment until balanced.
+func (s *stickyBalanceStrategy) performReassignments(reassignablePartitions []topicPartitionAssignment, currentAssignment map[string][]topicPartitionAssignment, prevAssignment map[topicPartitionAssignment]consumerGenerationPair, sortedCurrentSubscriptions []string, consumer2AllPotentialPartitions map[string][]topicPartitionAssignment, partition2AllPotentialConsumers map[topicPartitionAssignment][]string, currentPartitionConsumer map[topicPartitionAssignment]string) bool {
+	reassignmentPerformed := false
+	modified := false
+
+	// repeat reassignment until no partition can be moved to improve the balance
+	for {
+		modified = false
+		// reassign all reassignable partitions (starting from the partition with least potential consumers and if needed)
+		// until the full list is processed or a balance is achieved
+		for _, partition := range reassignablePartitions {
+			if isBalanced(currentAssignment, sortedCurrentSubscriptions, consumer2AllPotentialPartitions) {
+				break
+			}
+
+			// the partition must have at least two consumers
+			if len(partition2AllPotentialConsumers[partition]) <= 1 {
+				Logger.Printf("Expected more than one potential consumer for partition %s topic %d", partition.Topic, partition.Partition)
+			}
+
+			// the partition must have a consumer
+			consumer := currentPartitionConsumer[partition]
+			if consumer == "" {
+				Logger.Printf("Expected topic %s partition %d to be assigned to a consumer", partition.Topic, partition.Partition)
+			}
+
+			if _, exists := prevAssignment[partition]; exists {
+				if len(currentAssignment[consumer]) > (len(currentAssignment[prevAssignment[partition].MemberID]) + 1) {
+					sortedCurrentSubscriptions = s.reassignPartition(partition, currentAssignment, sortedCurrentSubscriptions, currentPartitionConsumer, prevAssignment[partition].MemberID)
+					reassignmentPerformed = true
+					modified = true
+					continue
+				}
+			}
+
+			// check if a better-suited consumer exists for the partition; if so, reassign it
+			for _, otherConsumer := range partition2AllPotentialConsumers[partition] {
+				if len(currentAssignment[consumer]) > (len(currentAssignment[otherConsumer]) + 1) {
+					sortedCurrentSubscriptions = s.reassignPartitionToNewConsumer(partition, currentAssignment, sortedCurrentSubscriptions, currentPartitionConsumer, consumer2AllPotentialPartitions)
+					reassignmentPerformed = true
+					modified = true
+					break
+				}
+			}
+		}
+		if !modified {
+			return reassignmentPerformed
+		}
+	}
+}
+
+// Identify a new consumer for a topic partition and reassign it.
+func (s *stickyBalanceStrategy) reassignPartitionToNewConsumer(partition topicPartitionAssignment, currentAssignment map[string][]topicPartitionAssignment, sortedCurrentSubscriptions []string, currentPartitionConsumer map[topicPartitionAssignment]string, consumer2AllPotentialPartitions map[string][]topicPartitionAssignment) []string {
+	for _, anotherConsumer := range sortedCurrentSubscriptions {
+		if memberAssignmentsIncludeTopicPartition(consumer2AllPotentialPartitions[anotherConsumer], partition) {
+			return s.reassignPartition(partition, currentAssignment, sortedCurrentSubscriptions, currentPartitionConsumer, anotherConsumer)
+		}
+	}
+	return sortedCurrentSubscriptions
+}
+
+// Reassign a specific partition to a new consumer
+func (s *stickyBalanceStrategy) reassignPartition(partition topicPartitionAssignment, currentAssignment map[string][]topicPartitionAssignment, sortedCurrentSubscriptions []string, currentPartitionConsumer map[topicPartitionAssignment]string, newConsumer string) []string {
+	consumer := currentPartitionConsumer[partition]
+	// find the correct partition movement considering the stickiness requirement
+	partitionToBeMoved := s.movements.getTheActualPartitionToBeMoved(partition, consumer, newConsumer)
+	return s.processPartitionMovement(partitionToBeMoved, newConsumer, currentAssignment, sortedCurrentSubscriptions, currentPartitionConsumer)
+}
+
+// Track the movement of a topic partition after assignment
+func (s *stickyBalanceStrategy) processPartitionMovement(partition topicPartitionAssignment, newConsumer string, currentAssignment map[string][]topicPartitionAssignment, sortedCurrentSubscriptions []string, currentPartitionConsumer map[topicPartitionAssignment]string) []string {
+	oldConsumer := currentPartitionConsumer[partition]
+	s.movements.movePartition(partition, oldConsumer, newConsumer)
+
+	currentAssignment[oldConsumer] = removeTopicPartitionFromMemberAssignments(currentAssignment[oldConsumer], partition)
+	currentAssignment[newConsumer] = append(currentAssignment[newConsumer], partition)
+	currentPartitionConsumer[partition] = newConsumer
+	return sortMemberIDsByPartitionAssignments(currentAssignment)
+}
+
+// Determine whether a specific consumer should be considered for topic partition assignment.
+func canConsumerParticipateInReassignment(memberID string, currentAssignment map[string][]topicPartitionAssignment, consumer2AllPotentialPartitions map[string][]topicPartitionAssignment, partition2AllPotentialConsumers map[topicPartitionAssignment][]string) bool {
+	currentPartitions := currentAssignment[memberID]
+	currentAssignmentSize := len(currentPartitions)
+	maxAssignmentSize := len(consumer2AllPotentialPartitions[memberID])
+	if currentAssignmentSize > maxAssignmentSize {
+		Logger.Printf("The consumer %s is assigned more partitions than the maximum possible", memberID)
+	}
+	if currentAssignmentSize < maxAssignmentSize {
+		// if a consumer is not assigned all its potential partitions it is subject to reassignment
+		return true
+	}
+	for _, partition := range currentPartitions {
+		if canTopicPartitionParticipateInReassignment(partition, partition2AllPotentialConsumers) {
+			return true
+		}
+	}
+	return false
+}
+
+// Only consider reassigning those topic partitions that have two or more potential consumers.
+func canTopicPartitionParticipateInReassignment(partition topicPartitionAssignment, partition2AllPotentialConsumers map[topicPartitionAssignment][]string) bool {
+	return len(partition2AllPotentialConsumers[partition]) >= 2
+}
+
+// The assignment should improve the overall balance of the partition assignments to consumers.
+func assignPartition(partition topicPartitionAssignment, sortedCurrentSubscriptions []string, currentAssignment map[string][]topicPartitionAssignment, consumer2AllPotentialPartitions map[string][]topicPartitionAssignment, currentPartitionConsumer map[topicPartitionAssignment]string) []string {
+	for _, memberID := range sortedCurrentSubscriptions {
+		if memberAssignmentsIncludeTopicPartition(consumer2AllPotentialPartitions[memberID], partition) {
+			currentAssignment[memberID] = append(currentAssignment[memberID], partition)
+			currentPartitionConsumer[partition] = memberID
+			break
+		}
+	}
+	return sortMemberIDsByPartitionAssignments(currentAssignment)
+}
+
+// Deserialize topic partition assignment data to aid with creation of a sticky assignment.
+func deserializeTopicPartitionAssignment(userDataBytes []byte) (StickyAssignorUserData, error) {
+	userDataV1 := &StickyAssignorUserDataV1{}
+	if err := decode(userDataBytes, userDataV1); err != nil {
+		userDataV0 := &StickyAssignorUserDataV0{}
+		if err := decode(userDataBytes, userDataV0); err != nil {
+			return nil, err
+		}
+		return userDataV0, nil
+	}
+	return userDataV1, nil
+}
+
+// filterAssignedPartitions returns a map of consumer group members to their list of previously-assigned topic partitions, limited
+// to those topic partitions currently reported by the Kafka cluster.
+func filterAssignedPartitions(currentAssignment map[string][]topicPartitionAssignment, partition2AllPotentialConsumers map[topicPartitionAssignment][]string) map[string][]topicPartitionAssignment {
+	assignments := deepCopyAssignment(currentAssignment)
+	for memberID, partitions := range assignments {
+		// perform in-place filtering
+		i := 0
+		for _, partition := range partitions {
+			if _, exists := partition2AllPotentialConsumers[partition]; exists {
+				partitions[i] = partition
+				i++
+			}
+		}
+		assignments[memberID] = partitions[:i]
+	}
+	return assignments
+}
+
+func removeTopicPartitionFromMemberAssignments(assignments []topicPartitionAssignment, topic topicPartitionAssignment) []topicPartitionAssignment {
+	for i, assignment := range assignments {
+		if assignment == topic {
+			return append(assignments[:i], assignments[i+1:]...)
+		}
+	}
+	return assignments
+}
+
+func memberAssignmentsIncludeTopicPartition(assignments []topicPartitionAssignment, topic topicPartitionAssignment) bool {
+	for _, assignment := range assignments {
+		if assignment == topic {
+			return true
+		}
+	}
+	return false
+}
+
+func sortPartitions(currentAssignment map[string][]topicPartitionAssignment, partitionsWithADifferentPreviousAssignment map[topicPartitionAssignment]consumerGenerationPair, isFreshAssignment bool, partition2AllPotentialConsumers map[topicPartitionAssignment][]string, consumer2AllPotentialPartitions map[string][]topicPartitionAssignment) []topicPartitionAssignment {
+	unassignedPartitions := make(map[topicPartitionAssignment]bool, len(partition2AllPotentialConsumers))
+	for partition := range partition2AllPotentialConsumers {
+		unassignedPartitions[partition] = true
+	}
+
+	sortedPartitions := make([]topicPartitionAssignment, 0)
+	if !isFreshAssignment && areSubscriptionsIdentical(partition2AllPotentialConsumers, consumer2AllPotentialPartitions) {
+		// if this is a reassignment and the subscriptions are identical (all consumers can consumer from all topics)
+		// then we just need to simply list partitions in a round robin fashion (from consumers with
+		// most assigned partitions to those with least)
+		assignments := filterAssignedPartitions(currentAssignment, partition2AllPotentialConsumers)
+
+		// use priority-queue to evaluate consumer group members in descending-order based on
+		// the number of topic partition assignments (i.e. consumers with most assignments first)
+		pq := make(assignmentPriorityQueue, len(assignments))
+		i := 0
+		for consumerID, consumerAssignments := range assignments {
+			pq[i] = &consumerGroupMember{
+				id:          consumerID,
+				assignments: consumerAssignments,
+			}
+			i++
+		}
+		heap.Init(&pq)
+
+		for {
+			// loop until no consumer-group members remain
+			if pq.Len() == 0 {
+				break
+			}
+			member := pq[0]
+
+			// partitions that were assigned to a different consumer last time
+			var prevPartitionIndex int
+			for i, partition := range member.assignments {
+				if _, exists := partitionsWithADifferentPreviousAssignment[partition]; exists {
+					prevPartitionIndex = i
+					break
+				}
+			}
+
+			if len(member.assignments) > 0 {
+				partition := member.assignments[prevPartitionIndex]
+				sortedPartitions = append(sortedPartitions, partition)
+				delete(unassignedPartitions, partition)
+				if prevPartitionIndex == 0 {
+					member.assignments = member.assignments[1:]
+				} else {
+					member.assignments = append(member.assignments[:prevPartitionIndex], member.assignments[prevPartitionIndex+1:]...)
+				}
+				heap.Fix(&pq, 0)
+			} else {
+				heap.Pop(&pq)
+			}
+		}
+
+		for partition := range unassignedPartitions {
+			sortedPartitions = append(sortedPartitions, partition)
+		}
+	} else {
+		// an ascending sorted set of topic partitions based on how many consumers can potentially use them
+		sortedPartitions = sortPartitionsByPotentialConsumerAssignments(partition2AllPotentialConsumers)
+	}
+	return sortedPartitions
+}
+
+func sortMemberIDsByPartitionAssignments(assignments map[string][]topicPartitionAssignment) []string {
+	// sort the members by the number of partition assignments in ascending order
+	sortedMemberIDs := make([]string, 0, len(assignments))
+	for memberID := range assignments {
+		sortedMemberIDs = append(sortedMemberIDs, memberID)
+	}
+	sort.SliceStable(sortedMemberIDs, func(i, j int) bool {
+		ret := len(assignments[sortedMemberIDs[i]]) - len(assignments[sortedMemberIDs[j]])
+		if ret == 0 {
+			return sortedMemberIDs[i] < sortedMemberIDs[j]
+		}
+		return len(assignments[sortedMemberIDs[i]]) < len(assignments[sortedMemberIDs[j]])
+	})
+	return sortedMemberIDs
+}
+
+func sortPartitionsByPotentialConsumerAssignments(partition2AllPotentialConsumers map[topicPartitionAssignment][]string) []topicPartitionAssignment {
+	// sort the members by the number of partition assignments in descending order
+	sortedPartionIDs := make([]topicPartitionAssignment, len(partition2AllPotentialConsumers))
+	i := 0
+	for partition := range partition2AllPotentialConsumers {
+		sortedPartionIDs[i] = partition
+		i++
+	}
+	sort.Slice(sortedPartionIDs, func(i, j int) bool {
+		if len(partition2AllPotentialConsumers[sortedPartionIDs[i]]) == len(partition2AllPotentialConsumers[sortedPartionIDs[j]]) {
+			ret := strings.Compare(sortedPartionIDs[i].Topic, sortedPartionIDs[j].Topic)
+			if ret == 0 {
+				return sortedPartionIDs[i].Partition < sortedPartionIDs[j].Partition
+			}
+			return ret < 0
+		}
+		return len(partition2AllPotentialConsumers[sortedPartionIDs[i]]) < len(partition2AllPotentialConsumers[sortedPartionIDs[j]])
+	})
+	return sortedPartionIDs
+}
+
+func deepCopyPartitions(src []topicPartitionAssignment) []topicPartitionAssignment {
+	dst := make([]topicPartitionAssignment, len(src))
+	for i, partition := range src {
+		dst[i] = partition
+	}
+	return dst
+}
+
+func deepCopyAssignment(assignment map[string][]topicPartitionAssignment) map[string][]topicPartitionAssignment {
+	copy := make(map[string][]topicPartitionAssignment, len(assignment))
+	for memberID, subscriptions := range assignment {
+		copy[memberID] = append(subscriptions[:0:0], subscriptions...)
+	}
+	return copy
+}
+
+func areSubscriptionsIdentical(partition2AllPotentialConsumers map[topicPartitionAssignment][]string, consumer2AllPotentialPartitions map[string][]topicPartitionAssignment) bool {
+	curMembers := make(map[string]int)
+	for _, cur := range partition2AllPotentialConsumers {
+		if len(curMembers) == 0 {
+			for _, curMembersElem := range cur {
+				curMembers[curMembersElem]++
+			}
+			continue
+		}
+
+		if len(curMembers) != len(cur) {
+			return false
+		}
+
+		yMap := make(map[string]int)
+		for _, yElem := range cur {
+			yMap[yElem]++
+		}
+
+		for curMembersMapKey, curMembersMapVal := range curMembers {
+			if yMap[curMembersMapKey] != curMembersMapVal {
+				return false
+			}
+		}
+	}
+
+	curPartitions := make(map[topicPartitionAssignment]int)
+	for _, cur := range consumer2AllPotentialPartitions {
+		if len(curPartitions) == 0 {
+			for _, curPartitionElem := range cur {
+				curPartitions[curPartitionElem]++
+			}
+			continue
+		}
+
+		if len(curPartitions) != len(cur) {
+			return false
+		}
+
+		yMap := make(map[topicPartitionAssignment]int)
+		for _, yElem := range cur {
+			yMap[yElem]++
+		}
+
+		for curMembersMapKey, curMembersMapVal := range curPartitions {
+			if yMap[curMembersMapKey] != curMembersMapVal {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// We need to process subscriptions' user data with each consumer's reported generation in mind
+// higher generations overwrite lower generations in case of a conflict
+// note that a conflict could exist only if user data is for different generations
+func prepopulateCurrentAssignments(members map[string]ConsumerGroupMemberMetadata) (map[string][]topicPartitionAssignment, map[topicPartitionAssignment]consumerGenerationPair, error) {
+	currentAssignment := make(map[string][]topicPartitionAssignment)
+	prevAssignment := make(map[topicPartitionAssignment]consumerGenerationPair)
+
+	// for each partition we create a sorted map of its consumers by generation
+	sortedPartitionConsumersByGeneration := make(map[topicPartitionAssignment]map[int]string)
+	for memberID, meta := range members {
+		consumerUserData, err := deserializeTopicPartitionAssignment(meta.UserData)
+		if err != nil {
+			return nil, nil, err
+		}
+		for _, partition := range consumerUserData.partitions() {
+			if consumers, exists := sortedPartitionConsumersByGeneration[partition]; exists {
+				if consumerUserData.hasGeneration() {
+					if _, generationExists := consumers[consumerUserData.generation()]; generationExists {
+						// same partition is assigned to two consumers during the same rebalance.
+						// log a warning and skip this record
+						Logger.Printf("Topic %s Partition %d is assigned to multiple consumers following sticky assignment generation %d", partition.Topic, partition.Partition, consumerUserData.generation())
+						continue
+					} else {
+						consumers[consumerUserData.generation()] = memberID
+					}
+				} else {
+					consumers[defaultGeneration] = memberID
+				}
+			} else {
+				generation := defaultGeneration
+				if consumerUserData.hasGeneration() {
+					generation = consumerUserData.generation()
+				}
+				sortedPartitionConsumersByGeneration[partition] = map[int]string{generation: memberID}
+			}
+		}
+	}
+
+	// prevAssignment holds the prior ConsumerGenerationPair (before current) of each partition
+	// current and previous consumers are the last two consumers of each partition in the above sorted map
+	for partition, consumers := range sortedPartitionConsumersByGeneration {
+		// sort consumers by generation in decreasing order
+		var generations []int
+		for generation := range consumers {
+			generations = append(generations, generation)
+		}
+		sort.Sort(sort.Reverse(sort.IntSlice(generations)))
+
+		consumer := consumers[generations[0]]
+		if _, exists := currentAssignment[consumer]; !exists {
+			currentAssignment[consumer] = []topicPartitionAssignment{partition}
+		} else {
+			currentAssignment[consumer] = append(currentAssignment[consumer], partition)
+		}
+
+		// check for previous assignment, if any
+		if len(generations) > 1 {
+			prevAssignment[partition] = consumerGenerationPair{
+				MemberID:   consumers[generations[1]],
+				Generation: generations[1],
+			}
+		}
+	}
+	return currentAssignment, prevAssignment, nil
+}
+
+type consumerGenerationPair struct {
+	MemberID   string
+	Generation int
+}
+
+// consumerPair represents a pair of Kafka consumer ids involved in a partition reassignment.
+type consumerPair struct {
+	SrcMemberID string
+	DstMemberID string
+}
+
+// partitionMovements maintains some data structures to simplify lookup of partition movements among consumers.
+type partitionMovements struct {
+	PartitionMovementsByTopic map[string]map[consumerPair]map[topicPartitionAssignment]bool
+	Movements                 map[topicPartitionAssignment]consumerPair
+}
+
+func (p *partitionMovements) removeMovementRecordOfPartition(partition topicPartitionAssignment) consumerPair {
+	pair := p.Movements[partition]
+	delete(p.Movements, partition)
+
+	partitionMovementsForThisTopic := p.PartitionMovementsByTopic[partition.Topic]
+	delete(partitionMovementsForThisTopic[pair], partition)
+	if len(partitionMovementsForThisTopic[pair]) == 0 {
+		delete(partitionMovementsForThisTopic, pair)
+	}
+	if len(p.PartitionMovementsByTopic[partition.Topic]) == 0 {
+		delete(p.PartitionMovementsByTopic, partition.Topic)
+	}
+	return pair
+}
+
+func (p *partitionMovements) addPartitionMovementRecord(partition topicPartitionAssignment, pair consumerPair) {
+	p.Movements[partition] = pair
+	if _, exists := p.PartitionMovementsByTopic[partition.Topic]; !exists {
+		p.PartitionMovementsByTopic[partition.Topic] = make(map[consumerPair]map[topicPartitionAssignment]bool)
+	}
+	partitionMovementsForThisTopic := p.PartitionMovementsByTopic[partition.Topic]
+	if _, exists := partitionMovementsForThisTopic[pair]; !exists {
+		partitionMovementsForThisTopic[pair] = make(map[topicPartitionAssignment]bool)
+	}
+	partitionMovementsForThisTopic[pair][partition] = true
+}
+
+func (p *partitionMovements) movePartition(partition topicPartitionAssignment, oldConsumer, newConsumer string) {
+	pair := consumerPair{
+		SrcMemberID: oldConsumer,
+		DstMemberID: newConsumer,
+	}
+	if _, exists := p.Movements[partition]; exists {
+		// this partition has previously moved
+		existingPair := p.removeMovementRecordOfPartition(partition)
+		if existingPair.DstMemberID != oldConsumer {
+			Logger.Printf("Existing pair DstMemberID %s was not equal to the oldConsumer ID %s", existingPair.DstMemberID, oldConsumer)
+		}
+		if existingPair.SrcMemberID != newConsumer {
+			// the partition is not moving back to its previous consumer
+			p.addPartitionMovementRecord(partition, consumerPair{
+				SrcMemberID: existingPair.SrcMemberID,
+				DstMemberID: newConsumer,
+			})
+		}
+	} else {
+		p.addPartitionMovementRecord(partition, pair)
+	}
+}
+
+func (p *partitionMovements) getTheActualPartitionToBeMoved(partition topicPartitionAssignment, oldConsumer, newConsumer string) topicPartitionAssignment {
+	if _, exists := p.PartitionMovementsByTopic[partition.Topic]; !exists {
+		return partition
+	}
+	if _, exists := p.Movements[partition]; exists {
+		// this partition has previously moved
+		if oldConsumer != p.Movements[partition].DstMemberID {
+			Logger.Printf("Partition movement DstMemberID %s was not equal to the oldConsumer ID %s", p.Movements[partition].DstMemberID, oldConsumer)
+		}
+		oldConsumer = p.Movements[partition].SrcMemberID
+	}
+
+	partitionMovementsForThisTopic := p.PartitionMovementsByTopic[partition.Topic]
+	reversePair := consumerPair{
+		SrcMemberID: newConsumer,
+		DstMemberID: oldConsumer,
+	}
+	if _, exists := partitionMovementsForThisTopic[reversePair]; !exists {
+		return partition
+	}
+	var reversePairPartition topicPartitionAssignment
+	for otherPartition := range partitionMovementsForThisTopic[reversePair] {
+		reversePairPartition = otherPartition
+	}
+	return reversePairPartition
+}
+
+func (p *partitionMovements) isLinked(src, dst string, pairs []consumerPair, currentPath []string) ([]string, bool) {
+	if src == dst {
+		return currentPath, false
+	}
+	if len(pairs) == 0 {
+		return currentPath, false
+	}
+	for _, pair := range pairs {
+		if src == pair.SrcMemberID && dst == pair.DstMemberID {
+			currentPath = append(currentPath, src, dst)
+			return currentPath, true
+		}
+	}
+
+	for _, pair := range pairs {
+		if pair.SrcMemberID == src {
+			// create a deep copy of the pairs, excluding the current pair
+			reducedSet := make([]consumerPair, len(pairs)-1)
+			i := 0
+			for _, p := range pairs {
+				if p != pair {
+					reducedSet[i] = pair
+					i++
+				}
+			}
+
+			currentPath = append(currentPath, pair.SrcMemberID)
+			return p.isLinked(pair.DstMemberID, dst, reducedSet, currentPath)
+		}
+	}
+	return currentPath, false
+}
+
+func (p *partitionMovements) in(cycle []string, cycles [][]string) bool {
+	superCycle := make([]string, len(cycle)-1)
+	for i := 0; i < len(cycle)-1; i++ {
+		superCycle[i] = cycle[i]
+	}
+	for _, c := range cycle {
+		superCycle = append(superCycle, c)
+	}
+	for _, foundCycle := range cycles {
+		if len(foundCycle) == len(cycle) && indexOfSubList(superCycle, foundCycle) != -1 {
+			return true
+		}
+	}
+	return false
+}
+
+func (p *partitionMovements) hasCycles(pairs []consumerPair) bool {
+	cycles := make([][]string, 0)
+	for _, pair := range pairs {
+		// create a deep copy of the pairs, excluding the current pair
+		reducedPairs := make([]consumerPair, len(pairs)-1)
+		i := 0
+		for _, p := range pairs {
+			if p != pair {
+				reducedPairs[i] = pair
+				i++
+			}
+		}
+		if path, linked := p.isLinked(pair.DstMemberID, pair.SrcMemberID, reducedPairs, []string{pair.SrcMemberID}); linked {
+			if !p.in(path, cycles) {
+				cycles = append(cycles, path)
+				Logger.Printf("A cycle of length %d was found: %v", len(path)-1, path)
+			}
+		}
+	}
+
+	// for now we want to make sure there is no partition movements of the same topic between a pair of consumers.
+	// the odds of finding a cycle among more than two consumers seem to be very low (according to various randomized
+	// tests with the given sticky algorithm) that it should not worth the added complexity of handling those cases.
+	for _, cycle := range cycles {
+		if len(cycle) == 3 {
+			return true
+		}
+	}
+	return false
+}
+
+func (p *partitionMovements) isSticky() bool {
+	for topic, movements := range p.PartitionMovementsByTopic {
+		movementPairs := make([]consumerPair, len(movements))
+		i := 0
+		for pair := range movements {
+			movementPairs[i] = pair
+			i++
+		}
+		if p.hasCycles(movementPairs) {
+			Logger.Printf("Stickiness is violated for topic %s", topic)
+			Logger.Printf("Partition movements for this topic occurred among the following consumer pairs: %v", movements)
+			return false
+		}
+	}
+	return true
+}
+
+func indexOfSubList(source []string, target []string) int {
+	targetSize := len(target)
+	maxCandidate := len(source) - targetSize
+nextCand:
+	for candidate := 0; candidate <= maxCandidate; candidate++ {
+		j := candidate
+		for i := 0; i < targetSize; i++ {
+			if target[i] != source[j] {
+				// Element mismatch, try next cand
+				continue nextCand
+			}
+			j++
+		}
+		// All elements of candidate matched target
+		return candidate
+	}
+	return -1
+}
+
+type consumerGroupMember struct {
+	id          string
+	assignments []topicPartitionAssignment
+}
+
+// assignmentPriorityQueue is a priority-queue of consumer group members that is sorted
+// in descending order (most assignments to least assignments).
+type assignmentPriorityQueue []*consumerGroupMember
+
+func (pq assignmentPriorityQueue) Len() int { return len(pq) }
+
+func (pq assignmentPriorityQueue) Less(i, j int) bool {
+	// order asssignment priority queue in descending order using assignment-count/member-id
+	if len(pq[i].assignments) == len(pq[j].assignments) {
+		return strings.Compare(pq[i].id, pq[j].id) > 0
+	}
+	return len(pq[i].assignments) > len(pq[j].assignments)
+}
+
+func (pq assignmentPriorityQueue) Swap(i, j int) {
+	pq[i], pq[j] = pq[j], pq[i]
+}
+
+func (pq *assignmentPriorityQueue) Push(x interface{}) {
+	member := x.(*consumerGroupMember)
+	*pq = append(*pq, member)
+}
+
+func (pq *assignmentPriorityQueue) Pop() interface{} {
+	old := *pq
+	n := len(old)
+	member := old[n-1]
+	*pq = old[0 : n-1]
+	return member
+}
diff --git a/vendor/github.com/Shopify/sarama/broker.go b/vendor/github.com/Shopify/sarama/broker.go
new file mode 100644
index 0000000..8146749
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/broker.go
@@ -0,0 +1,1354 @@
+package sarama
+
+import (
+	"crypto/tls"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"net"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	metrics "github.com/rcrowley/go-metrics"
+)
+
+// Broker represents a single Kafka broker connection. All operations on this object are entirely concurrency-safe.
+type Broker struct {
+	conf *Config
+	rack *string
+
+	id            int32
+	addr          string
+	correlationID int32
+	conn          net.Conn
+	connErr       error
+	lock          sync.Mutex
+	opened        int32
+	responses     chan responsePromise
+	done          chan bool
+
+	registeredMetrics []string
+
+	incomingByteRate       metrics.Meter
+	requestRate            metrics.Meter
+	requestSize            metrics.Histogram
+	requestLatency         metrics.Histogram
+	outgoingByteRate       metrics.Meter
+	responseRate           metrics.Meter
+	responseSize           metrics.Histogram
+	brokerIncomingByteRate metrics.Meter
+	brokerRequestRate      metrics.Meter
+	brokerRequestSize      metrics.Histogram
+	brokerRequestLatency   metrics.Histogram
+	brokerOutgoingByteRate metrics.Meter
+	brokerResponseRate     metrics.Meter
+	brokerResponseSize     metrics.Histogram
+
+	kerberosAuthenticator GSSAPIKerberosAuth
+}
+
+// SASLMechanism specifies the SASL mechanism the client uses to authenticate with the broker
+type SASLMechanism string
+
+const (
+	// SASLTypeOAuth represents the SASL/OAUTHBEARER mechanism (Kafka 2.0.0+)
+	SASLTypeOAuth = "OAUTHBEARER"
+	// SASLTypePlaintext represents the SASL/PLAIN mechanism
+	SASLTypePlaintext = "PLAIN"
+	// SASLTypeSCRAMSHA256 represents the SCRAM-SHA-256 mechanism.
+	SASLTypeSCRAMSHA256 = "SCRAM-SHA-256"
+	// SASLTypeSCRAMSHA512 represents the SCRAM-SHA-512 mechanism.
+	SASLTypeSCRAMSHA512 = "SCRAM-SHA-512"
+	SASLTypeGSSAPI      = "GSSAPI"
+	// SASLHandshakeV0 is v0 of the Kafka SASL handshake protocol. Client and
+	// server negotiate SASL auth using opaque packets.
+	SASLHandshakeV0 = int16(0)
+	// SASLHandshakeV1 is v1 of the Kafka SASL handshake protocol. Client and
+	// server negotiate SASL by wrapping tokens with Kafka protocol headers.
+	SASLHandshakeV1 = int16(1)
+	// SASLExtKeyAuth is the reserved extension key name sent as part of the
+	// SASL/OAUTHBEARER intial client response
+	SASLExtKeyAuth = "auth"
+)
+
+// AccessToken contains an access token used to authenticate a
+// SASL/OAUTHBEARER client along with associated metadata.
+type AccessToken struct {
+	// Token is the access token payload.
+	Token string
+	// Extensions is a optional map of arbitrary key-value pairs that can be
+	// sent with the SASL/OAUTHBEARER initial client response. These values are
+	// ignored by the SASL server if they are unexpected. This feature is only
+	// supported by Kafka >= 2.1.0.
+	Extensions map[string]string
+}
+
+// AccessTokenProvider is the interface that encapsulates how implementors
+// can generate access tokens for Kafka broker authentication.
+type AccessTokenProvider interface {
+	// Token returns an access token. The implementation should ensure token
+	// reuse so that multiple calls at connect time do not create multiple
+	// tokens. The implementation should also periodically refresh the token in
+	// order to guarantee that each call returns an unexpired token.  This
+	// method should not block indefinitely--a timeout error should be returned
+	// after a short period of inactivity so that the broker connection logic
+	// can log debugging information and retry.
+	Token() (*AccessToken, error)
+}
+
+// SCRAMClient is a an interface to a SCRAM
+// client implementation.
+type SCRAMClient interface {
+	// Begin prepares the client for the SCRAM exchange
+	// with the server with a user name and a password
+	Begin(userName, password, authzID string) error
+	// Step steps client through the SCRAM exchange. It is
+	// called repeatedly until it errors or `Done` returns true.
+	Step(challenge string) (response string, err error)
+	// Done should return true when the SCRAM conversation
+	// is over.
+	Done() bool
+}
+
+type responsePromise struct {
+	requestTime   time.Time
+	correlationID int32
+	packets       chan []byte
+	errors        chan error
+}
+
+// NewBroker creates and returns a Broker targeting the given host:port address.
+// This does not attempt to actually connect, you have to call Open() for that.
+func NewBroker(addr string) *Broker {
+	return &Broker{id: -1, addr: addr}
+}
+
+// Open tries to connect to the Broker if it is not already connected or connecting, but does not block
+// waiting for the connection to complete. This means that any subsequent operations on the broker will
+// block waiting for the connection to succeed or fail. To get the effect of a fully synchronous Open call,
+// follow it by a call to Connected(). The only errors Open will return directly are ConfigurationError or
+// AlreadyConnected. If conf is nil, the result of NewConfig() is used.
+func (b *Broker) Open(conf *Config) error {
+	if !atomic.CompareAndSwapInt32(&b.opened, 0, 1) {
+		return ErrAlreadyConnected
+	}
+
+	if conf == nil {
+		conf = NewConfig()
+	}
+
+	err := conf.Validate()
+	if err != nil {
+		return err
+	}
+
+	b.lock.Lock()
+
+	go withRecover(func() {
+		defer b.lock.Unlock()
+
+		dialer := net.Dialer{
+			Timeout:   conf.Net.DialTimeout,
+			KeepAlive: conf.Net.KeepAlive,
+			LocalAddr: conf.Net.LocalAddr,
+		}
+
+		if conf.Net.TLS.Enable {
+			b.conn, b.connErr = tls.DialWithDialer(&dialer, "tcp", b.addr, conf.Net.TLS.Config)
+		} else if conf.Net.Proxy.Enable {
+			b.conn, b.connErr = conf.Net.Proxy.Dialer.Dial("tcp", b.addr)
+		} else {
+			b.conn, b.connErr = dialer.Dial("tcp", b.addr)
+		}
+		if b.connErr != nil {
+			Logger.Printf("Failed to connect to broker %s: %s\n", b.addr, b.connErr)
+			b.conn = nil
+			atomic.StoreInt32(&b.opened, 0)
+			return
+		}
+		b.conn = newBufConn(b.conn)
+
+		b.conf = conf
+
+		// Create or reuse the global metrics shared between brokers
+		b.incomingByteRate = metrics.GetOrRegisterMeter("incoming-byte-rate", conf.MetricRegistry)
+		b.requestRate = metrics.GetOrRegisterMeter("request-rate", conf.MetricRegistry)
+		b.requestSize = getOrRegisterHistogram("request-size", conf.MetricRegistry)
+		b.requestLatency = getOrRegisterHistogram("request-latency-in-ms", conf.MetricRegistry)
+		b.outgoingByteRate = metrics.GetOrRegisterMeter("outgoing-byte-rate", conf.MetricRegistry)
+		b.responseRate = metrics.GetOrRegisterMeter("response-rate", conf.MetricRegistry)
+		b.responseSize = getOrRegisterHistogram("response-size", conf.MetricRegistry)
+		// Do not gather metrics for seeded broker (only used during bootstrap) because they share
+		// the same id (-1) and are already exposed through the global metrics above
+		if b.id >= 0 {
+			b.registerMetrics()
+		}
+
+		if conf.Net.SASL.Enable {
+
+			b.connErr = b.authenticateViaSASL()
+
+			if b.connErr != nil {
+				err = b.conn.Close()
+				if err == nil {
+					Logger.Printf("Closed connection to broker %s\n", b.addr)
+				} else {
+					Logger.Printf("Error while closing connection to broker %s: %s\n", b.addr, err)
+				}
+				b.conn = nil
+				atomic.StoreInt32(&b.opened, 0)
+				return
+			}
+		}
+
+		b.done = make(chan bool)
+		b.responses = make(chan responsePromise, b.conf.Net.MaxOpenRequests-1)
+
+		if b.id >= 0 {
+			Logger.Printf("Connected to broker at %s (registered as #%d)\n", b.addr, b.id)
+		} else {
+			Logger.Printf("Connected to broker at %s (unregistered)\n", b.addr)
+		}
+		go withRecover(b.responseReceiver)
+	})
+
+	return nil
+}
+
+// Connected returns true if the broker is connected and false otherwise. If the broker is not
+// connected but it had tried to connect, the error from that connection attempt is also returned.
+func (b *Broker) Connected() (bool, error) {
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	return b.conn != nil, b.connErr
+}
+
+//Close closes the broker resources
+func (b *Broker) Close() error {
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	if b.conn == nil {
+		return ErrNotConnected
+	}
+
+	close(b.responses)
+	<-b.done
+
+	err := b.conn.Close()
+
+	b.conn = nil
+	b.connErr = nil
+	b.done = nil
+	b.responses = nil
+
+	b.unregisterMetrics()
+
+	if err == nil {
+		Logger.Printf("Closed connection to broker %s\n", b.addr)
+	} else {
+		Logger.Printf("Error while closing connection to broker %s: %s\n", b.addr, err)
+	}
+
+	atomic.StoreInt32(&b.opened, 0)
+
+	return err
+}
+
+// ID returns the broker ID retrieved from Kafka's metadata, or -1 if that is not known.
+func (b *Broker) ID() int32 {
+	return b.id
+}
+
+// Addr returns the broker address as either retrieved from Kafka's metadata or passed to NewBroker.
+func (b *Broker) Addr() string {
+	return b.addr
+}
+
+// Rack returns the broker's rack as retrieved from Kafka's metadata or the
+// empty string if it is not known.  The returned value corresponds to the
+// broker's broker.rack configuration setting.  Requires protocol version to be
+// at least v0.10.0.0.
+func (b *Broker) Rack() string {
+	if b.rack == nil {
+		return ""
+	}
+	return *b.rack
+}
+
+//GetMetadata send a metadata request and returns a metadata response or error
+func (b *Broker) GetMetadata(request *MetadataRequest) (*MetadataResponse, error) {
+	response := new(MetadataResponse)
+
+	err := b.sendAndReceive(request, response)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//GetConsumerMetadata send a consumer metadata request and returns a consumer metadata response or error
+func (b *Broker) GetConsumerMetadata(request *ConsumerMetadataRequest) (*ConsumerMetadataResponse, error) {
+	response := new(ConsumerMetadataResponse)
+
+	err := b.sendAndReceive(request, response)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//FindCoordinator sends a find coordinate request and returns a response or error
+func (b *Broker) FindCoordinator(request *FindCoordinatorRequest) (*FindCoordinatorResponse, error) {
+	response := new(FindCoordinatorResponse)
+
+	err := b.sendAndReceive(request, response)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//GetAvailableOffsets return an offset response or error
+func (b *Broker) GetAvailableOffsets(request *OffsetRequest) (*OffsetResponse, error) {
+	response := new(OffsetResponse)
+
+	err := b.sendAndReceive(request, response)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//Produce returns a produce response or error
+func (b *Broker) Produce(request *ProduceRequest) (*ProduceResponse, error) {
+	var (
+		response *ProduceResponse
+		err      error
+	)
+
+	if request.RequiredAcks == NoResponse {
+		err = b.sendAndReceive(request, nil)
+	} else {
+		response = new(ProduceResponse)
+		err = b.sendAndReceive(request, response)
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//Fetch returns a FetchResponse or error
+func (b *Broker) Fetch(request *FetchRequest) (*FetchResponse, error) {
+	response := new(FetchResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//CommitOffset return an Offset commit reponse or error
+func (b *Broker) CommitOffset(request *OffsetCommitRequest) (*OffsetCommitResponse, error) {
+	response := new(OffsetCommitResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//FetchOffset returns an offset fetch response or error
+func (b *Broker) FetchOffset(request *OffsetFetchRequest) (*OffsetFetchResponse, error) {
+	response := new(OffsetFetchResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//JoinGroup returns a join group response or error
+func (b *Broker) JoinGroup(request *JoinGroupRequest) (*JoinGroupResponse, error) {
+	response := new(JoinGroupResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//SyncGroup returns a sync group response or error
+func (b *Broker) SyncGroup(request *SyncGroupRequest) (*SyncGroupResponse, error) {
+	response := new(SyncGroupResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//LeaveGroup return a leave group response or error
+func (b *Broker) LeaveGroup(request *LeaveGroupRequest) (*LeaveGroupResponse, error) {
+	response := new(LeaveGroupResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//Heartbeat returns a heartbeat response or error
+func (b *Broker) Heartbeat(request *HeartbeatRequest) (*HeartbeatResponse, error) {
+	response := new(HeartbeatResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//ListGroups return a list group response or error
+func (b *Broker) ListGroups(request *ListGroupsRequest) (*ListGroupsResponse, error) {
+	response := new(ListGroupsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//DescribeGroups return describe group response or error
+func (b *Broker) DescribeGroups(request *DescribeGroupsRequest) (*DescribeGroupsResponse, error) {
+	response := new(DescribeGroupsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//ApiVersions return api version response or error
+func (b *Broker) ApiVersions(request *ApiVersionsRequest) (*ApiVersionsResponse, error) {
+	response := new(ApiVersionsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//CreateTopics send a create topic request and returns create topic response
+func (b *Broker) CreateTopics(request *CreateTopicsRequest) (*CreateTopicsResponse, error) {
+	response := new(CreateTopicsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//DeleteTopics sends a delete topic request and returns delete topic response
+func (b *Broker) DeleteTopics(request *DeleteTopicsRequest) (*DeleteTopicsResponse, error) {
+	response := new(DeleteTopicsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//CreatePartitions sends a create partition request and returns create
+//partitions response or error
+func (b *Broker) CreatePartitions(request *CreatePartitionsRequest) (*CreatePartitionsResponse, error) {
+	response := new(CreatePartitionsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//DeleteRecords send a request to delete records and return delete record
+//response or error
+func (b *Broker) DeleteRecords(request *DeleteRecordsRequest) (*DeleteRecordsResponse, error) {
+	response := new(DeleteRecordsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//DescribeAcls sends a describe acl request and returns a response or error
+func (b *Broker) DescribeAcls(request *DescribeAclsRequest) (*DescribeAclsResponse, error) {
+	response := new(DescribeAclsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//CreateAcls sends a create acl request and returns a response or error
+func (b *Broker) CreateAcls(request *CreateAclsRequest) (*CreateAclsResponse, error) {
+	response := new(CreateAclsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//DeleteAcls sends a delete acl request and returns a response or error
+func (b *Broker) DeleteAcls(request *DeleteAclsRequest) (*DeleteAclsResponse, error) {
+	response := new(DeleteAclsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//InitProducerID sends an init producer request and returns a response or error
+func (b *Broker) InitProducerID(request *InitProducerIDRequest) (*InitProducerIDResponse, error) {
+	response := new(InitProducerIDResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//AddPartitionsToTxn send a request to add partition to txn and returns
+//a response or error
+func (b *Broker) AddPartitionsToTxn(request *AddPartitionsToTxnRequest) (*AddPartitionsToTxnResponse, error) {
+	response := new(AddPartitionsToTxnResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//AddOffsetsToTxn sends a request to add offsets to txn and returns a response
+//or error
+func (b *Broker) AddOffsetsToTxn(request *AddOffsetsToTxnRequest) (*AddOffsetsToTxnResponse, error) {
+	response := new(AddOffsetsToTxnResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//EndTxn sends a request to end txn and returns a response or error
+func (b *Broker) EndTxn(request *EndTxnRequest) (*EndTxnResponse, error) {
+	response := new(EndTxnResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//TxnOffsetCommit sends a request to commit transaction offsets and returns
+//a response or error
+func (b *Broker) TxnOffsetCommit(request *TxnOffsetCommitRequest) (*TxnOffsetCommitResponse, error) {
+	response := new(TxnOffsetCommitResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//DescribeConfigs sends a request to describe config and returns a response or
+//error
+func (b *Broker) DescribeConfigs(request *DescribeConfigsRequest) (*DescribeConfigsResponse, error) {
+	response := new(DescribeConfigsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//AlterConfigs sends a request to alter config and return a response or error
+func (b *Broker) AlterConfigs(request *AlterConfigsRequest) (*AlterConfigsResponse, error) {
+	response := new(AlterConfigsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//DeleteGroups sends a request to delete groups and returns a response or error
+func (b *Broker) DeleteGroups(request *DeleteGroupsRequest) (*DeleteGroupsResponse, error) {
+	response := new(DeleteGroupsResponse)
+
+	if err := b.sendAndReceive(request, response); err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+//DescribeLogDirs sends a request to get the broker's log dir paths and sizes
+func (b *Broker) DescribeLogDirs(request *DescribeLogDirsRequest) (*DescribeLogDirsResponse, error) {
+	response := new(DescribeLogDirsResponse)
+
+	err := b.sendAndReceive(request, response)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
+// readFull ensures the conn ReadDeadline has been setup before making a
+// call to io.ReadFull
+func (b *Broker) readFull(buf []byte) (n int, err error) {
+	if err := b.conn.SetReadDeadline(time.Now().Add(b.conf.Net.ReadTimeout)); err != nil {
+		return 0, err
+	}
+
+	return io.ReadFull(b.conn, buf)
+}
+
+// write  ensures the conn WriteDeadline has been setup before making a
+// call to conn.Write
+func (b *Broker) write(buf []byte) (n int, err error) {
+	if err := b.conn.SetWriteDeadline(time.Now().Add(b.conf.Net.WriteTimeout)); err != nil {
+		return 0, err
+	}
+
+	return b.conn.Write(buf)
+}
+
+func (b *Broker) send(rb protocolBody, promiseResponse bool) (*responsePromise, error) {
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	if b.conn == nil {
+		if b.connErr != nil {
+			return nil, b.connErr
+		}
+		return nil, ErrNotConnected
+	}
+
+	if !b.conf.Version.IsAtLeast(rb.requiredVersion()) {
+		return nil, ErrUnsupportedVersion
+	}
+
+	req := &request{correlationID: b.correlationID, clientID: b.conf.ClientID, body: rb}
+	buf, err := encode(req, b.conf.MetricRegistry)
+	if err != nil {
+		return nil, err
+	}
+
+	requestTime := time.Now()
+	bytes, err := b.write(buf)
+	b.updateOutgoingCommunicationMetrics(bytes)
+	if err != nil {
+		return nil, err
+	}
+	b.correlationID++
+
+	if !promiseResponse {
+		// Record request latency without the response
+		b.updateRequestLatencyMetrics(time.Since(requestTime))
+		return nil, nil
+	}
+
+	promise := responsePromise{requestTime, req.correlationID, make(chan []byte), make(chan error)}
+	b.responses <- promise
+
+	return &promise, nil
+}
+
+func (b *Broker) sendAndReceive(req protocolBody, res versionedDecoder) error {
+	promise, err := b.send(req, res != nil)
+	if err != nil {
+		return err
+	}
+
+	if promise == nil {
+		return nil
+	}
+
+	select {
+	case buf := <-promise.packets:
+		return versionedDecode(buf, res, req.version())
+	case err = <-promise.errors:
+		return err
+	}
+}
+
+func (b *Broker) decode(pd packetDecoder, version int16) (err error) {
+	b.id, err = pd.getInt32()
+	if err != nil {
+		return err
+	}
+
+	host, err := pd.getString()
+	if err != nil {
+		return err
+	}
+
+	port, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+
+	if version >= 1 {
+		b.rack, err = pd.getNullableString()
+		if err != nil {
+			return err
+		}
+	}
+
+	b.addr = net.JoinHostPort(host, fmt.Sprint(port))
+	if _, _, err := net.SplitHostPort(b.addr); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (b *Broker) encode(pe packetEncoder, version int16) (err error) {
+	host, portstr, err := net.SplitHostPort(b.addr)
+	if err != nil {
+		return err
+	}
+
+	port, err := strconv.Atoi(portstr)
+	if err != nil {
+		return err
+	}
+
+	pe.putInt32(b.id)
+
+	err = pe.putString(host)
+	if err != nil {
+		return err
+	}
+
+	pe.putInt32(int32(port))
+
+	if version >= 1 {
+		err = pe.putNullableString(b.rack)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (b *Broker) responseReceiver() {
+	var dead error
+	header := make([]byte, 8)
+
+	for response := range b.responses {
+		if dead != nil {
+			response.errors <- dead
+			continue
+		}
+
+		bytesReadHeader, err := b.readFull(header)
+		requestLatency := time.Since(response.requestTime)
+		if err != nil {
+			b.updateIncomingCommunicationMetrics(bytesReadHeader, requestLatency)
+			dead = err
+			response.errors <- err
+			continue
+		}
+
+		decodedHeader := responseHeader{}
+		err = decode(header, &decodedHeader)
+		if err != nil {
+			b.updateIncomingCommunicationMetrics(bytesReadHeader, requestLatency)
+			dead = err
+			response.errors <- err
+			continue
+		}
+		if decodedHeader.correlationID != response.correlationID {
+			b.updateIncomingCommunicationMetrics(bytesReadHeader, requestLatency)
+			// TODO if decoded ID < cur ID, discard until we catch up
+			// TODO if decoded ID > cur ID, save it so when cur ID catches up we have a response
+			dead = PacketDecodingError{fmt.Sprintf("correlation ID didn't match, wanted %d, got %d", response.correlationID, decodedHeader.correlationID)}
+			response.errors <- dead
+			continue
+		}
+
+		buf := make([]byte, decodedHeader.length-4)
+		bytesReadBody, err := b.readFull(buf)
+		b.updateIncomingCommunicationMetrics(bytesReadHeader+bytesReadBody, requestLatency)
+		if err != nil {
+			dead = err
+			response.errors <- err
+			continue
+		}
+
+		response.packets <- buf
+	}
+	close(b.done)
+}
+
+func (b *Broker) authenticateViaSASL() error {
+	switch b.conf.Net.SASL.Mechanism {
+	case SASLTypeOAuth:
+		return b.sendAndReceiveSASLOAuth(b.conf.Net.SASL.TokenProvider)
+	case SASLTypeSCRAMSHA256, SASLTypeSCRAMSHA512:
+		return b.sendAndReceiveSASLSCRAMv1()
+	case SASLTypeGSSAPI:
+		return b.sendAndReceiveKerberos()
+	default:
+		return b.sendAndReceiveSASLPlainAuth()
+	}
+}
+
+func (b *Broker) sendAndReceiveKerberos() error {
+	b.kerberosAuthenticator.Config = &b.conf.Net.SASL.GSSAPI
+	if b.kerberosAuthenticator.NewKerberosClientFunc == nil {
+		b.kerberosAuthenticator.NewKerberosClientFunc = NewKerberosClient
+	}
+	return b.kerberosAuthenticator.Authorize(b)
+}
+
+func (b *Broker) sendAndReceiveSASLHandshake(saslType SASLMechanism, version int16) error {
+	rb := &SaslHandshakeRequest{Mechanism: string(saslType), Version: version}
+
+	req := &request{correlationID: b.correlationID, clientID: b.conf.ClientID, body: rb}
+	buf, err := encode(req, b.conf.MetricRegistry)
+	if err != nil {
+		return err
+	}
+
+	requestTime := time.Now()
+	bytes, err := b.write(buf)
+	b.updateOutgoingCommunicationMetrics(bytes)
+	if err != nil {
+		Logger.Printf("Failed to send SASL handshake %s: %s\n", b.addr, err.Error())
+		return err
+	}
+	b.correlationID++
+
+	header := make([]byte, 8) // response header
+	_, err = b.readFull(header)
+	if err != nil {
+		Logger.Printf("Failed to read SASL handshake header : %s\n", err.Error())
+		return err
+	}
+
+	length := binary.BigEndian.Uint32(header[:4])
+	payload := make([]byte, length-4)
+	n, err := b.readFull(payload)
+	if err != nil {
+		Logger.Printf("Failed to read SASL handshake payload : %s\n", err.Error())
+		return err
+	}
+
+	b.updateIncomingCommunicationMetrics(n+8, time.Since(requestTime))
+	res := &SaslHandshakeResponse{}
+
+	err = versionedDecode(payload, res, 0)
+	if err != nil {
+		Logger.Printf("Failed to parse SASL handshake : %s\n", err.Error())
+		return err
+	}
+
+	if res.Err != ErrNoError {
+		Logger.Printf("Invalid SASL Mechanism : %s\n", res.Err.Error())
+		return res.Err
+	}
+
+	Logger.Print("Successful SASL handshake. Available mechanisms: ", res.EnabledMechanisms)
+	return nil
+}
+
+// Kafka 0.10.x supported SASL PLAIN/Kerberos via KAFKA-3149 (KIP-43).
+// Kafka 1.x.x onward added a SaslAuthenticate request/response message which
+// wraps the SASL flow in the Kafka protocol, which allows for returning
+// meaningful errors on authentication failure.
+//
+// In SASL Plain, Kafka expects the auth header to be in the following format
+// Message format (from https://tools.ietf.org/html/rfc4616):
+//
+//   message   = [authzid] UTF8NUL authcid UTF8NUL passwd
+//   authcid   = 1*SAFE ; MUST accept up to 255 octets
+//   authzid   = 1*SAFE ; MUST accept up to 255 octets
+//   passwd    = 1*SAFE ; MUST accept up to 255 octets
+//   UTF8NUL   = %x00 ; UTF-8 encoded NUL character
+//
+//   SAFE      = UTF1 / UTF2 / UTF3 / UTF4
+//                  ;; any UTF-8 encoded Unicode character except NUL
+//
+// With SASL v0 handshake and auth then:
+// When credentials are valid, Kafka returns a 4 byte array of null characters.
+// When credentials are invalid, Kafka closes the connection.
+//
+// With SASL v1 handshake and auth then:
+// When credentials are invalid, Kafka replies with a SaslAuthenticate response
+// containing an error code and message detailing the authentication failure.
+func (b *Broker) sendAndReceiveSASLPlainAuth() error {
+	// default to V0 to allow for backward compatability when SASL is enabled
+	// but not the handshake
+	if b.conf.Net.SASL.Handshake {
+
+		handshakeErr := b.sendAndReceiveSASLHandshake(SASLTypePlaintext, b.conf.Net.SASL.Version)
+		if handshakeErr != nil {
+			Logger.Printf("Error while performing SASL handshake %s\n", b.addr)
+			return handshakeErr
+		}
+	}
+
+	if b.conf.Net.SASL.Version == SASLHandshakeV1 {
+		return b.sendAndReceiveV1SASLPlainAuth()
+	}
+	return b.sendAndReceiveV0SASLPlainAuth()
+}
+
+// sendAndReceiveV0SASLPlainAuth flows the v0 sasl auth NOT wrapped in the kafka protocol
+func (b *Broker) sendAndReceiveV0SASLPlainAuth() error {
+
+	length := 1 + len(b.conf.Net.SASL.User) + 1 + len(b.conf.Net.SASL.Password)
+	authBytes := make([]byte, length+4) //4 byte length header + auth data
+	binary.BigEndian.PutUint32(authBytes, uint32(length))
+	copy(authBytes[4:], []byte("\x00"+b.conf.Net.SASL.User+"\x00"+b.conf.Net.SASL.Password))
+
+	requestTime := time.Now()
+	bytesWritten, err := b.write(authBytes)
+	b.updateOutgoingCommunicationMetrics(bytesWritten)
+	if err != nil {
+		Logger.Printf("Failed to write SASL auth header to broker %s: %s\n", b.addr, err.Error())
+		return err
+	}
+
+	header := make([]byte, 4)
+	n, err := b.readFull(header)
+	b.updateIncomingCommunicationMetrics(n, time.Since(requestTime))
+	// If the credentials are valid, we would get a 4 byte response filled with null characters.
+	// Otherwise, the broker closes the connection and we get an EOF
+	if err != nil {
+		Logger.Printf("Failed to read response while authenticating with SASL to broker %s: %s\n", b.addr, err.Error())
+		return err
+	}
+
+	Logger.Printf("SASL authentication successful with broker %s:%v - %v\n", b.addr, n, header)
+	return nil
+}
+
+// sendAndReceiveV1SASLPlainAuth flows the v1 sasl authentication using the kafka protocol
+func (b *Broker) sendAndReceiveV1SASLPlainAuth() error {
+	correlationID := b.correlationID
+
+	requestTime := time.Now()
+
+	bytesWritten, err := b.sendSASLPlainAuthClientResponse(correlationID)
+
+	b.updateOutgoingCommunicationMetrics(bytesWritten)
+
+	if err != nil {
+		Logger.Printf("Failed to write SASL auth header to broker %s: %s\n", b.addr, err.Error())
+		return err
+	}
+
+	b.correlationID++
+
+	bytesRead, err := b.receiveSASLServerResponse(&SaslAuthenticateResponse{}, correlationID)
+	b.updateIncomingCommunicationMetrics(bytesRead, time.Since(requestTime))
+
+	// With v1 sasl we get an error message set in the response we can return
+	if err != nil {
+		Logger.Printf("Error returned from broker during SASL flow %s: %s\n", b.addr, err.Error())
+		return err
+	}
+
+	return nil
+}
+
+// sendAndReceiveSASLOAuth performs the authentication flow as described by KIP-255
+// https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=75968876
+func (b *Broker) sendAndReceiveSASLOAuth(provider AccessTokenProvider) error {
+	if err := b.sendAndReceiveSASLHandshake(SASLTypeOAuth, SASLHandshakeV1); err != nil {
+		return err
+	}
+
+	token, err := provider.Token()
+	if err != nil {
+		return err
+	}
+
+	message, err := buildClientFirstMessage(token)
+	if err != nil {
+		return err
+	}
+
+	challenged, err := b.sendClientMessage(message)
+	if err != nil {
+		return err
+	}
+
+	if challenged {
+		// Abort the token exchange. The broker returns the failure code.
+		_, err = b.sendClientMessage([]byte(`\x01`))
+	}
+
+	return err
+}
+
+// sendClientMessage sends a SASL/OAUTHBEARER client message and returns true
+// if the broker responds with a challenge, in which case the token is
+// rejected.
+func (b *Broker) sendClientMessage(message []byte) (bool, error) {
+
+	requestTime := time.Now()
+	correlationID := b.correlationID
+
+	bytesWritten, err := b.sendSASLOAuthBearerClientMessage(message, correlationID)
+	if err != nil {
+		return false, err
+	}
+
+	b.updateOutgoingCommunicationMetrics(bytesWritten)
+	b.correlationID++
+
+	res := &SaslAuthenticateResponse{}
+	bytesRead, err := b.receiveSASLServerResponse(res, correlationID)
+
+	requestLatency := time.Since(requestTime)
+	b.updateIncomingCommunicationMetrics(bytesRead, requestLatency)
+
+	isChallenge := len(res.SaslAuthBytes) > 0
+
+	if isChallenge && err != nil {
+		Logger.Printf("Broker rejected authentication token: %s", res.SaslAuthBytes)
+	}
+
+	return isChallenge, err
+}
+
+func (b *Broker) sendAndReceiveSASLSCRAMv1() error {
+	if err := b.sendAndReceiveSASLHandshake(b.conf.Net.SASL.Mechanism, SASLHandshakeV1); err != nil {
+		return err
+	}
+
+	scramClient := b.conf.Net.SASL.SCRAMClientGeneratorFunc()
+	if err := scramClient.Begin(b.conf.Net.SASL.User, b.conf.Net.SASL.Password, b.conf.Net.SASL.SCRAMAuthzID); err != nil {
+		return fmt.Errorf("failed to start SCRAM exchange with the server: %s", err.Error())
+	}
+
+	msg, err := scramClient.Step("")
+	if err != nil {
+		return fmt.Errorf("failed to advance the SCRAM exchange: %s", err.Error())
+
+	}
+
+	for !scramClient.Done() {
+		requestTime := time.Now()
+		correlationID := b.correlationID
+		bytesWritten, err := b.sendSaslAuthenticateRequest(correlationID, []byte(msg))
+		if err != nil {
+			Logger.Printf("Failed to write SASL auth header to broker %s: %s\n", b.addr, err.Error())
+			return err
+		}
+
+		b.updateOutgoingCommunicationMetrics(bytesWritten)
+		b.correlationID++
+		challenge, err := b.receiveSaslAuthenticateResponse(correlationID)
+		if err != nil {
+			Logger.Printf("Failed to read response while authenticating with SASL to broker %s: %s\n", b.addr, err.Error())
+			return err
+		}
+
+		b.updateIncomingCommunicationMetrics(len(challenge), time.Since(requestTime))
+		msg, err = scramClient.Step(string(challenge))
+		if err != nil {
+			Logger.Println("SASL authentication failed", err)
+			return err
+		}
+	}
+
+	Logger.Println("SASL authentication succeeded")
+	return nil
+}
+
+func (b *Broker) sendSaslAuthenticateRequest(correlationID int32, msg []byte) (int, error) {
+	rb := &SaslAuthenticateRequest{msg}
+	req := &request{correlationID: correlationID, clientID: b.conf.ClientID, body: rb}
+	buf, err := encode(req, b.conf.MetricRegistry)
+	if err != nil {
+		return 0, err
+	}
+
+	return b.write(buf)
+}
+
+func (b *Broker) receiveSaslAuthenticateResponse(correlationID int32) ([]byte, error) {
+	buf := make([]byte, responseLengthSize+correlationIDSize)
+	_, err := b.readFull(buf)
+	if err != nil {
+		return nil, err
+	}
+
+	header := responseHeader{}
+	err = decode(buf, &header)
+	if err != nil {
+		return nil, err
+	}
+
+	if header.correlationID != correlationID {
+		return nil, fmt.Errorf("correlation ID didn't match, wanted %d, got %d", b.correlationID, header.correlationID)
+	}
+
+	buf = make([]byte, header.length-correlationIDSize)
+	_, err = b.readFull(buf)
+	if err != nil {
+		return nil, err
+	}
+
+	res := &SaslAuthenticateResponse{}
+	if err := versionedDecode(buf, res, 0); err != nil {
+		return nil, err
+	}
+	if res.Err != ErrNoError {
+		return nil, res.Err
+	}
+	return res.SaslAuthBytes, nil
+}
+
+// Build SASL/OAUTHBEARER initial client response as described by RFC-7628
+// https://tools.ietf.org/html/rfc7628
+func buildClientFirstMessage(token *AccessToken) ([]byte, error) {
+	var ext string
+
+	if token.Extensions != nil && len(token.Extensions) > 0 {
+		if _, ok := token.Extensions[SASLExtKeyAuth]; ok {
+			return []byte{}, fmt.Errorf("the extension `%s` is invalid", SASLExtKeyAuth)
+		}
+		ext = "\x01" + mapToString(token.Extensions, "=", "\x01")
+	}
+
+	resp := []byte(fmt.Sprintf("n,,\x01auth=Bearer %s%s\x01\x01", token.Token, ext))
+
+	return resp, nil
+}
+
+// mapToString returns a list of key-value pairs ordered by key.
+// keyValSep separates the key from the value. elemSep separates each pair.
+func mapToString(extensions map[string]string, keyValSep string, elemSep string) string {
+	buf := make([]string, 0, len(extensions))
+
+	for k, v := range extensions {
+		buf = append(buf, k+keyValSep+v)
+	}
+
+	sort.Strings(buf)
+
+	return strings.Join(buf, elemSep)
+}
+
+func (b *Broker) sendSASLPlainAuthClientResponse(correlationID int32) (int, error) {
+	authBytes := []byte("\x00" + b.conf.Net.SASL.User + "\x00" + b.conf.Net.SASL.Password)
+	rb := &SaslAuthenticateRequest{authBytes}
+	req := &request{correlationID: correlationID, clientID: b.conf.ClientID, body: rb}
+	buf, err := encode(req, b.conf.MetricRegistry)
+	if err != nil {
+		return 0, err
+	}
+
+	return b.write(buf)
+}
+
+func (b *Broker) sendSASLOAuthBearerClientMessage(initialResp []byte, correlationID int32) (int, error) {
+
+	rb := &SaslAuthenticateRequest{initialResp}
+
+	req := &request{correlationID: correlationID, clientID: b.conf.ClientID, body: rb}
+
+	buf, err := encode(req, b.conf.MetricRegistry)
+	if err != nil {
+		return 0, err
+	}
+
+	return b.write(buf)
+}
+
+func (b *Broker) receiveSASLServerResponse(res *SaslAuthenticateResponse, correlationID int32) (int, error) {
+	buf := make([]byte, responseLengthSize+correlationIDSize)
+	bytesRead, err := b.readFull(buf)
+	if err != nil {
+		return bytesRead, err
+	}
+
+	header := responseHeader{}
+	err = decode(buf, &header)
+	if err != nil {
+		return bytesRead, err
+	}
+
+	if header.correlationID != correlationID {
+		return bytesRead, fmt.Errorf("correlation ID didn't match, wanted %d, got %d", b.correlationID, header.correlationID)
+	}
+
+	buf = make([]byte, header.length-correlationIDSize)
+	c, err := b.readFull(buf)
+	bytesRead += c
+	if err != nil {
+		return bytesRead, err
+	}
+
+	if err := versionedDecode(buf, res, 0); err != nil {
+		return bytesRead, err
+	}
+
+	if res.Err != ErrNoError {
+		return bytesRead, res.Err
+	}
+
+	return bytesRead, nil
+}
+
+func (b *Broker) updateIncomingCommunicationMetrics(bytes int, requestLatency time.Duration) {
+	b.updateRequestLatencyMetrics(requestLatency)
+	b.responseRate.Mark(1)
+
+	if b.brokerResponseRate != nil {
+		b.brokerResponseRate.Mark(1)
+	}
+
+	responseSize := int64(bytes)
+	b.incomingByteRate.Mark(responseSize)
+	if b.brokerIncomingByteRate != nil {
+		b.brokerIncomingByteRate.Mark(responseSize)
+	}
+
+	b.responseSize.Update(responseSize)
+	if b.brokerResponseSize != nil {
+		b.brokerResponseSize.Update(responseSize)
+	}
+}
+
+func (b *Broker) updateRequestLatencyMetrics(requestLatency time.Duration) {
+	requestLatencyInMs := int64(requestLatency / time.Millisecond)
+	b.requestLatency.Update(requestLatencyInMs)
+
+	if b.brokerRequestLatency != nil {
+		b.brokerRequestLatency.Update(requestLatencyInMs)
+	}
+
+}
+
+func (b *Broker) updateOutgoingCommunicationMetrics(bytes int) {
+	b.requestRate.Mark(1)
+	if b.brokerRequestRate != nil {
+		b.brokerRequestRate.Mark(1)
+	}
+
+	requestSize := int64(bytes)
+	b.outgoingByteRate.Mark(requestSize)
+	if b.brokerOutgoingByteRate != nil {
+		b.brokerOutgoingByteRate.Mark(requestSize)
+	}
+
+	b.requestSize.Update(requestSize)
+	if b.brokerRequestSize != nil {
+		b.brokerRequestSize.Update(requestSize)
+	}
+
+}
+
+func (b *Broker) registerMetrics() {
+	b.brokerIncomingByteRate = b.registerMeter("incoming-byte-rate")
+	b.brokerRequestRate = b.registerMeter("request-rate")
+	b.brokerRequestSize = b.registerHistogram("request-size")
+	b.brokerRequestLatency = b.registerHistogram("request-latency-in-ms")
+	b.brokerOutgoingByteRate = b.registerMeter("outgoing-byte-rate")
+	b.brokerResponseRate = b.registerMeter("response-rate")
+	b.brokerResponseSize = b.registerHistogram("response-size")
+}
+
+func (b *Broker) unregisterMetrics() {
+	for _, name := range b.registeredMetrics {
+		b.conf.MetricRegistry.Unregister(name)
+	}
+}
+
+func (b *Broker) registerMeter(name string) metrics.Meter {
+	nameForBroker := getMetricNameForBroker(name, b)
+	b.registeredMetrics = append(b.registeredMetrics, nameForBroker)
+	return metrics.GetOrRegisterMeter(nameForBroker, b.conf.MetricRegistry)
+}
+
+func (b *Broker) registerHistogram(name string) metrics.Histogram {
+	nameForBroker := getMetricNameForBroker(name, b)
+	b.registeredMetrics = append(b.registeredMetrics, nameForBroker)
+	return getOrRegisterHistogram(nameForBroker, b.conf.MetricRegistry)
+}
diff --git a/vendor/github.com/Shopify/sarama/client.go b/vendor/github.com/Shopify/sarama/client.go
new file mode 100644
index 0000000..e5b3557
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/client.go
@@ -0,0 +1,1013 @@
+package sarama
+
+import (
+	"math/rand"
+	"sort"
+	"sync"
+	"time"
+)
+
+// Client is a generic Kafka client. It manages connections to one or more Kafka brokers.
+// You MUST call Close() on a client to avoid leaks, it will not be garbage-collected
+// automatically when it passes out of scope. It is safe to share a client amongst many
+// users, however Kafka will process requests from a single client strictly in serial,
+// so it is generally more efficient to use the default one client per producer/consumer.
+type Client interface {
+	// Config returns the Config struct of the client. This struct should not be
+	// altered after it has been created.
+	Config() *Config
+
+	// Controller returns the cluster controller broker. Requires Kafka 0.10 or higher.
+	Controller() (*Broker, error)
+
+	// Brokers returns the current set of active brokers as retrieved from cluster metadata.
+	Brokers() []*Broker
+
+	// Topics returns the set of available topics as retrieved from cluster metadata.
+	Topics() ([]string, error)
+
+	// Partitions returns the sorted list of all partition IDs for the given topic.
+	Partitions(topic string) ([]int32, error)
+
+	// WritablePartitions returns the sorted list of all writable partition IDs for
+	// the given topic, where "writable" means "having a valid leader accepting
+	// writes".
+	WritablePartitions(topic string) ([]int32, error)
+
+	// Leader returns the broker object that is the leader of the current
+	// topic/partition, as determined by querying the cluster metadata.
+	Leader(topic string, partitionID int32) (*Broker, error)
+
+	// Replicas returns the set of all replica IDs for the given partition.
+	Replicas(topic string, partitionID int32) ([]int32, error)
+
+	// InSyncReplicas returns the set of all in-sync replica IDs for the given
+	// partition. In-sync replicas are replicas which are fully caught up with
+	// the partition leader.
+	InSyncReplicas(topic string, partitionID int32) ([]int32, error)
+
+	// OfflineReplicas returns the set of all offline replica IDs for the given
+	// partition. Offline replicas are replicas which are offline
+	OfflineReplicas(topic string, partitionID int32) ([]int32, error)
+
+	// RefreshMetadata takes a list of topics and queries the cluster to refresh the
+	// available metadata for those topics. If no topics are provided, it will refresh
+	// metadata for all topics.
+	RefreshMetadata(topics ...string) error
+
+	// GetOffset queries the cluster to get the most recent available offset at the
+	// given time (in milliseconds) on the topic/partition combination.
+	// Time should be OffsetOldest for the earliest available offset,
+	// OffsetNewest for the offset of the message that will be produced next, or a time.
+	GetOffset(topic string, partitionID int32, time int64) (int64, error)
+
+	// Coordinator returns the coordinating broker for a consumer group. It will
+	// return a locally cached value if it's available. You can call
+	// RefreshCoordinator to update the cached value. This function only works on
+	// Kafka 0.8.2 and higher.
+	Coordinator(consumerGroup string) (*Broker, error)
+
+	// RefreshCoordinator retrieves the coordinator for a consumer group and stores it
+	// in local cache. This function only works on Kafka 0.8.2 and higher.
+	RefreshCoordinator(consumerGroup string) error
+
+	// InitProducerID retrieves information required for Idempotent Producer
+	InitProducerID() (*InitProducerIDResponse, error)
+
+	// Close shuts down all broker connections managed by this client. It is required
+	// to call this function before a client object passes out of scope, as it will
+	// otherwise leak memory. You must close any Producers or Consumers using a client
+	// before you close the client.
+	Close() error
+
+	// Closed returns true if the client has already had Close called on it
+	Closed() bool
+}
+
+const (
+	// OffsetNewest stands for the log head offset, i.e. the offset that will be
+	// assigned to the next message that will be produced to the partition. You
+	// can send this to a client's GetOffset method to get this offset, or when
+	// calling ConsumePartition to start consuming new messages.
+	OffsetNewest int64 = -1
+	// OffsetOldest stands for the oldest offset available on the broker for a
+	// partition. You can send this to a client's GetOffset method to get this
+	// offset, or when calling ConsumePartition to start consuming from the
+	// oldest offset that is still available on the broker.
+	OffsetOldest int64 = -2
+)
+
+type client struct {
+	conf           *Config
+	closer, closed chan none // for shutting down background metadata updater
+
+	// the broker addresses given to us through the constructor are not guaranteed to be returned in
+	// the cluster metadata (I *think* it only returns brokers who are currently leading partitions?)
+	// so we store them separately
+	seedBrokers []*Broker
+	deadSeeds   []*Broker
+
+	controllerID   int32                                   // cluster controller broker id
+	brokers        map[int32]*Broker                       // maps broker ids to brokers
+	metadata       map[string]map[int32]*PartitionMetadata // maps topics to partition ids to metadata
+	metadataTopics map[string]none                         // topics that need to collect metadata
+	coordinators   map[string]int32                        // Maps consumer group names to coordinating broker IDs
+
+	// If the number of partitions is large, we can get some churn calling cachedPartitions,
+	// so the result is cached.  It is important to update this value whenever metadata is changed
+	cachedPartitionsResults map[string][maxPartitionIndex][]int32
+
+	lock sync.RWMutex // protects access to the maps that hold cluster state.
+}
+
+// NewClient creates a new Client. It connects to one of the given broker addresses
+// and uses that broker to automatically fetch metadata on the rest of the kafka cluster. If metadata cannot
+// be retrieved from any of the given broker addresses, the client is not created.
+func NewClient(addrs []string, conf *Config) (Client, error) {
+	Logger.Println("Initializing new client")
+
+	if conf == nil {
+		conf = NewConfig()
+	}
+
+	if err := conf.Validate(); err != nil {
+		return nil, err
+	}
+
+	if len(addrs) < 1 {
+		return nil, ConfigurationError("You must provide at least one broker address")
+	}
+
+	client := &client{
+		conf:                    conf,
+		closer:                  make(chan none),
+		closed:                  make(chan none),
+		brokers:                 make(map[int32]*Broker),
+		metadata:                make(map[string]map[int32]*PartitionMetadata),
+		metadataTopics:          make(map[string]none),
+		cachedPartitionsResults: make(map[string][maxPartitionIndex][]int32),
+		coordinators:            make(map[string]int32),
+	}
+
+	random := rand.New(rand.NewSource(time.Now().UnixNano()))
+	for _, index := range random.Perm(len(addrs)) {
+		client.seedBrokers = append(client.seedBrokers, NewBroker(addrs[index]))
+	}
+
+	if conf.Metadata.Full {
+		// do an initial fetch of all cluster metadata by specifying an empty list of topics
+		err := client.RefreshMetadata()
+		switch err {
+		case nil:
+			break
+		case ErrLeaderNotAvailable, ErrReplicaNotAvailable, ErrTopicAuthorizationFailed, ErrClusterAuthorizationFailed:
+			// indicates that maybe part of the cluster is down, but is not fatal to creating the client
+			Logger.Println(err)
+		default:
+			close(client.closed) // we haven't started the background updater yet, so we have to do this manually
+			_ = client.Close()
+			return nil, err
+		}
+	}
+	go withRecover(client.backgroundMetadataUpdater)
+
+	Logger.Println("Successfully initialized new client")
+
+	return client, nil
+}
+
+func (client *client) Config() *Config {
+	return client.conf
+}
+
+func (client *client) Brokers() []*Broker {
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+	brokers := make([]*Broker, 0, len(client.brokers))
+	for _, broker := range client.brokers {
+		brokers = append(brokers, broker)
+	}
+	return brokers
+}
+
+func (client *client) InitProducerID() (*InitProducerIDResponse, error) {
+	var err error
+	for broker := client.any(); broker != nil; broker = client.any() {
+
+		req := &InitProducerIDRequest{}
+
+		response, err := broker.InitProducerID(req)
+		switch err.(type) {
+		case nil:
+			return response, nil
+		default:
+			// some error, remove that broker and try again
+			Logger.Printf("Client got error from broker %d when issuing InitProducerID : %v\n", broker.ID(), err)
+			_ = broker.Close()
+			client.deregisterBroker(broker)
+		}
+	}
+	return nil, err
+}
+
+func (client *client) Close() error {
+	if client.Closed() {
+		// Chances are this is being called from a defer() and the error will go unobserved
+		// so we go ahead and log the event in this case.
+		Logger.Printf("Close() called on already closed client")
+		return ErrClosedClient
+	}
+
+	// shutdown and wait for the background thread before we take the lock, to avoid races
+	close(client.closer)
+	<-client.closed
+
+	client.lock.Lock()
+	defer client.lock.Unlock()
+	Logger.Println("Closing Client")
+
+	for _, broker := range client.brokers {
+		safeAsyncClose(broker)
+	}
+
+	for _, broker := range client.seedBrokers {
+		safeAsyncClose(broker)
+	}
+
+	client.brokers = nil
+	client.metadata = nil
+	client.metadataTopics = nil
+
+	return nil
+}
+
+func (client *client) Closed() bool {
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+
+	return client.brokers == nil
+}
+
+func (client *client) Topics() ([]string, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+
+	ret := make([]string, 0, len(client.metadata))
+	for topic := range client.metadata {
+		ret = append(ret, topic)
+	}
+
+	return ret, nil
+}
+
+func (client *client) MetadataTopics() ([]string, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+
+	ret := make([]string, 0, len(client.metadataTopics))
+	for topic := range client.metadataTopics {
+		ret = append(ret, topic)
+	}
+
+	return ret, nil
+}
+
+func (client *client) Partitions(topic string) ([]int32, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	partitions := client.cachedPartitions(topic, allPartitions)
+
+	if len(partitions) == 0 {
+		err := client.RefreshMetadata(topic)
+		if err != nil {
+			return nil, err
+		}
+		partitions = client.cachedPartitions(topic, allPartitions)
+	}
+
+	// no partitions found after refresh metadata
+	if len(partitions) == 0 {
+		return nil, ErrUnknownTopicOrPartition
+	}
+
+	return partitions, nil
+}
+
+func (client *client) WritablePartitions(topic string) ([]int32, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	partitions := client.cachedPartitions(topic, writablePartitions)
+
+	// len==0 catches when it's nil (no such topic) and the odd case when every single
+	// partition is undergoing leader election simultaneously. Callers have to be able to handle
+	// this function returning an empty slice (which is a valid return value) but catching it
+	// here the first time (note we *don't* catch it below where we return ErrUnknownTopicOrPartition) triggers
+	// a metadata refresh as a nicety so callers can just try again and don't have to manually
+	// trigger a refresh (otherwise they'd just keep getting a stale cached copy).
+	if len(partitions) == 0 {
+		err := client.RefreshMetadata(topic)
+		if err != nil {
+			return nil, err
+		}
+		partitions = client.cachedPartitions(topic, writablePartitions)
+	}
+
+	if partitions == nil {
+		return nil, ErrUnknownTopicOrPartition
+	}
+
+	return partitions, nil
+}
+
+func (client *client) Replicas(topic string, partitionID int32) ([]int32, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	metadata := client.cachedMetadata(topic, partitionID)
+
+	if metadata == nil {
+		err := client.RefreshMetadata(topic)
+		if err != nil {
+			return nil, err
+		}
+		metadata = client.cachedMetadata(topic, partitionID)
+	}
+
+	if metadata == nil {
+		return nil, ErrUnknownTopicOrPartition
+	}
+
+	if metadata.Err == ErrReplicaNotAvailable {
+		return dupInt32Slice(metadata.Replicas), metadata.Err
+	}
+	return dupInt32Slice(metadata.Replicas), nil
+}
+
+func (client *client) InSyncReplicas(topic string, partitionID int32) ([]int32, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	metadata := client.cachedMetadata(topic, partitionID)
+
+	if metadata == nil {
+		err := client.RefreshMetadata(topic)
+		if err != nil {
+			return nil, err
+		}
+		metadata = client.cachedMetadata(topic, partitionID)
+	}
+
+	if metadata == nil {
+		return nil, ErrUnknownTopicOrPartition
+	}
+
+	if metadata.Err == ErrReplicaNotAvailable {
+		return dupInt32Slice(metadata.Isr), metadata.Err
+	}
+	return dupInt32Slice(metadata.Isr), nil
+}
+
+func (client *client) OfflineReplicas(topic string, partitionID int32) ([]int32, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	metadata := client.cachedMetadata(topic, partitionID)
+
+	if metadata == nil {
+		err := client.RefreshMetadata(topic)
+		if err != nil {
+			return nil, err
+		}
+		metadata = client.cachedMetadata(topic, partitionID)
+	}
+
+	if metadata == nil {
+		return nil, ErrUnknownTopicOrPartition
+	}
+
+	if metadata.Err == ErrReplicaNotAvailable {
+		return dupInt32Slice(metadata.OfflineReplicas), metadata.Err
+	}
+	return dupInt32Slice(metadata.OfflineReplicas), nil
+}
+
+func (client *client) Leader(topic string, partitionID int32) (*Broker, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	leader, err := client.cachedLeader(topic, partitionID)
+
+	if leader == nil {
+		err = client.RefreshMetadata(topic)
+		if err != nil {
+			return nil, err
+		}
+		leader, err = client.cachedLeader(topic, partitionID)
+	}
+
+	return leader, err
+}
+
+func (client *client) RefreshMetadata(topics ...string) error {
+	if client.Closed() {
+		return ErrClosedClient
+	}
+
+	// Prior to 0.8.2, Kafka will throw exceptions on an empty topic and not return a proper
+	// error. This handles the case by returning an error instead of sending it
+	// off to Kafka. See: https://github.com/Shopify/sarama/pull/38#issuecomment-26362310
+	for _, topic := range topics {
+		if len(topic) == 0 {
+			return ErrInvalidTopic // this is the error that 0.8.2 and later correctly return
+		}
+	}
+
+	deadline := time.Time{}
+	if client.conf.Metadata.Timeout > 0 {
+		deadline = time.Now().Add(client.conf.Metadata.Timeout)
+	}
+	return client.tryRefreshMetadata(topics, client.conf.Metadata.Retry.Max, deadline)
+}
+
+func (client *client) GetOffset(topic string, partitionID int32, time int64) (int64, error) {
+	if client.Closed() {
+		return -1, ErrClosedClient
+	}
+
+	offset, err := client.getOffset(topic, partitionID, time)
+
+	if err != nil {
+		if err := client.RefreshMetadata(topic); err != nil {
+			return -1, err
+		}
+		return client.getOffset(topic, partitionID, time)
+	}
+
+	return offset, err
+}
+
+func (client *client) Controller() (*Broker, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	if !client.conf.Version.IsAtLeast(V0_10_0_0) {
+		return nil, ErrUnsupportedVersion
+	}
+
+	controller := client.cachedController()
+	if controller == nil {
+		if err := client.refreshMetadata(); err != nil {
+			return nil, err
+		}
+		controller = client.cachedController()
+	}
+
+	if controller == nil {
+		return nil, ErrControllerNotAvailable
+	}
+
+	_ = controller.Open(client.conf)
+	return controller, nil
+}
+
+func (client *client) Coordinator(consumerGroup string) (*Broker, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	coordinator := client.cachedCoordinator(consumerGroup)
+
+	if coordinator == nil {
+		if err := client.RefreshCoordinator(consumerGroup); err != nil {
+			return nil, err
+		}
+		coordinator = client.cachedCoordinator(consumerGroup)
+	}
+
+	if coordinator == nil {
+		return nil, ErrConsumerCoordinatorNotAvailable
+	}
+
+	_ = coordinator.Open(client.conf)
+	return coordinator, nil
+}
+
+func (client *client) RefreshCoordinator(consumerGroup string) error {
+	if client.Closed() {
+		return ErrClosedClient
+	}
+
+	response, err := client.getConsumerMetadata(consumerGroup, client.conf.Metadata.Retry.Max)
+	if err != nil {
+		return err
+	}
+
+	client.lock.Lock()
+	defer client.lock.Unlock()
+	client.registerBroker(response.Coordinator)
+	client.coordinators[consumerGroup] = response.Coordinator.ID()
+	return nil
+}
+
+// private broker management helpers
+
+// registerBroker makes sure a broker received by a Metadata or Coordinator request is registered
+// in the brokers map. It returns the broker that is registered, which may be the provided broker,
+// or a previously registered Broker instance. You must hold the write lock before calling this function.
+func (client *client) registerBroker(broker *Broker) {
+	if client.brokers == nil {
+		Logger.Printf("cannot register broker #%d at %s, client already closed", broker.ID(), broker.Addr())
+		return
+	}
+
+	if client.brokers[broker.ID()] == nil {
+		client.brokers[broker.ID()] = broker
+		Logger.Printf("client/brokers registered new broker #%d at %s", broker.ID(), broker.Addr())
+	} else if broker.Addr() != client.brokers[broker.ID()].Addr() {
+		safeAsyncClose(client.brokers[broker.ID()])
+		client.brokers[broker.ID()] = broker
+		Logger.Printf("client/brokers replaced registered broker #%d with %s", broker.ID(), broker.Addr())
+	}
+}
+
+// deregisterBroker removes a broker from the seedsBroker list, and if it's
+// not the seedbroker, removes it from brokers map completely.
+func (client *client) deregisterBroker(broker *Broker) {
+	client.lock.Lock()
+	defer client.lock.Unlock()
+
+	if len(client.seedBrokers) > 0 && broker == client.seedBrokers[0] {
+		client.deadSeeds = append(client.deadSeeds, broker)
+		client.seedBrokers = client.seedBrokers[1:]
+	} else {
+		// we do this so that our loop in `tryRefreshMetadata` doesn't go on forever,
+		// but we really shouldn't have to; once that loop is made better this case can be
+		// removed, and the function generally can be renamed from `deregisterBroker` to
+		// `nextSeedBroker` or something
+		Logger.Printf("client/brokers deregistered broker #%d at %s", broker.ID(), broker.Addr())
+		delete(client.brokers, broker.ID())
+	}
+}
+
+func (client *client) resurrectDeadBrokers() {
+	client.lock.Lock()
+	defer client.lock.Unlock()
+
+	Logger.Printf("client/brokers resurrecting %d dead seed brokers", len(client.deadSeeds))
+	client.seedBrokers = append(client.seedBrokers, client.deadSeeds...)
+	client.deadSeeds = nil
+}
+
+func (client *client) any() *Broker {
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+
+	if len(client.seedBrokers) > 0 {
+		_ = client.seedBrokers[0].Open(client.conf)
+		return client.seedBrokers[0]
+	}
+
+	// not guaranteed to be random *or* deterministic
+	for _, broker := range client.brokers {
+		_ = broker.Open(client.conf)
+		return broker
+	}
+
+	return nil
+}
+
+// private caching/lazy metadata helpers
+
+type partitionType int
+
+const (
+	allPartitions partitionType = iota
+	writablePartitions
+	// If you add any more types, update the partition cache in update()
+
+	// Ensure this is the last partition type value
+	maxPartitionIndex
+)
+
+func (client *client) cachedMetadata(topic string, partitionID int32) *PartitionMetadata {
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+
+	partitions := client.metadata[topic]
+	if partitions != nil {
+		return partitions[partitionID]
+	}
+
+	return nil
+}
+
+func (client *client) cachedPartitions(topic string, partitionSet partitionType) []int32 {
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+
+	partitions, exists := client.cachedPartitionsResults[topic]
+
+	if !exists {
+		return nil
+	}
+	return partitions[partitionSet]
+}
+
+func (client *client) setPartitionCache(topic string, partitionSet partitionType) []int32 {
+	partitions := client.metadata[topic]
+
+	if partitions == nil {
+		return nil
+	}
+
+	ret := make([]int32, 0, len(partitions))
+	for _, partition := range partitions {
+		if partitionSet == writablePartitions && partition.Err == ErrLeaderNotAvailable {
+			continue
+		}
+		ret = append(ret, partition.ID)
+	}
+
+	sort.Sort(int32Slice(ret))
+	return ret
+}
+
+func (client *client) cachedLeader(topic string, partitionID int32) (*Broker, error) {
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+
+	partitions := client.metadata[topic]
+	if partitions != nil {
+		metadata, ok := partitions[partitionID]
+		if ok {
+			if metadata.Err == ErrLeaderNotAvailable {
+				return nil, ErrLeaderNotAvailable
+			}
+			b := client.brokers[metadata.Leader]
+			if b == nil {
+				return nil, ErrLeaderNotAvailable
+			}
+			_ = b.Open(client.conf)
+			return b, nil
+		}
+	}
+
+	return nil, ErrUnknownTopicOrPartition
+}
+
+func (client *client) getOffset(topic string, partitionID int32, time int64) (int64, error) {
+	broker, err := client.Leader(topic, partitionID)
+	if err != nil {
+		return -1, err
+	}
+
+	request := &OffsetRequest{}
+	if client.conf.Version.IsAtLeast(V0_10_1_0) {
+		request.Version = 1
+	}
+	request.AddBlock(topic, partitionID, time, 1)
+
+	response, err := broker.GetAvailableOffsets(request)
+	if err != nil {
+		_ = broker.Close()
+		return -1, err
+	}
+
+	block := response.GetBlock(topic, partitionID)
+	if block == nil {
+		_ = broker.Close()
+		return -1, ErrIncompleteResponse
+	}
+	if block.Err != ErrNoError {
+		return -1, block.Err
+	}
+	if len(block.Offsets) != 1 {
+		return -1, ErrOffsetOutOfRange
+	}
+
+	return block.Offsets[0], nil
+}
+
+// core metadata update logic
+
+func (client *client) backgroundMetadataUpdater() {
+	defer close(client.closed)
+
+	if client.conf.Metadata.RefreshFrequency == time.Duration(0) {
+		return
+	}
+
+	ticker := time.NewTicker(client.conf.Metadata.RefreshFrequency)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			if err := client.refreshMetadata(); err != nil {
+				Logger.Println("Client background metadata update:", err)
+			}
+		case <-client.closer:
+			return
+		}
+	}
+}
+
+func (client *client) refreshMetadata() error {
+	topics := []string{}
+
+	if !client.conf.Metadata.Full {
+		if specificTopics, err := client.MetadataTopics(); err != nil {
+			return err
+		} else if len(specificTopics) == 0 {
+			return ErrNoTopicsToUpdateMetadata
+		} else {
+			topics = specificTopics
+		}
+	}
+
+	if err := client.RefreshMetadata(topics...); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (client *client) tryRefreshMetadata(topics []string, attemptsRemaining int, deadline time.Time) error {
+	pastDeadline := func(backoff time.Duration) bool {
+		if !deadline.IsZero() && time.Now().Add(backoff).After(deadline) {
+			// we are past the deadline
+			return true
+		}
+		return false
+	}
+	retry := func(err error) error {
+		if attemptsRemaining > 0 {
+			backoff := client.computeBackoff(attemptsRemaining)
+			if pastDeadline(backoff) {
+				Logger.Println("client/metadata skipping last retries as we would go past the metadata timeout")
+				return err
+			}
+			Logger.Printf("client/metadata retrying after %dms... (%d attempts remaining)\n", client.conf.Metadata.Retry.Backoff/time.Millisecond, attemptsRemaining)
+			if backoff > 0 {
+				time.Sleep(backoff)
+			}
+			return client.tryRefreshMetadata(topics, attemptsRemaining-1, deadline)
+		}
+		return err
+	}
+
+	broker := client.any()
+	for ; broker != nil && !pastDeadline(0); broker = client.any() {
+		allowAutoTopicCreation := true
+		if len(topics) > 0 {
+			Logger.Printf("client/metadata fetching metadata for %v from broker %s\n", topics, broker.addr)
+		} else {
+			allowAutoTopicCreation = false
+			Logger.Printf("client/metadata fetching metadata for all topics from broker %s\n", broker.addr)
+		}
+
+		req := &MetadataRequest{Topics: topics, AllowAutoTopicCreation: allowAutoTopicCreation}
+		if client.conf.Version.IsAtLeast(V1_0_0_0) {
+			req.Version = 5
+		} else if client.conf.Version.IsAtLeast(V0_10_0_0) {
+			req.Version = 1
+		}
+		response, err := broker.GetMetadata(req)
+		switch err.(type) {
+		case nil:
+			allKnownMetaData := len(topics) == 0
+			// valid response, use it
+			shouldRetry, err := client.updateMetadata(response, allKnownMetaData)
+			if shouldRetry {
+				Logger.Println("client/metadata found some partitions to be leaderless")
+				return retry(err) // note: err can be nil
+			}
+			return err
+
+		case PacketEncodingError:
+			// didn't even send, return the error
+			return err
+
+		case KError:
+			// if SASL auth error return as this _should_ be a non retryable err for all brokers
+			if err.(KError) == ErrSASLAuthenticationFailed {
+				Logger.Println("client/metadata failed SASL authentication")
+				return err
+			}
+
+			if err.(KError) == ErrTopicAuthorizationFailed {
+				Logger.Println("client is not authorized to access this topic. The topics were: ", topics)
+				return err
+			}
+			// else remove that broker and try again
+			Logger.Printf("client/metadata got error from broker %d while fetching metadata: %v\n", broker.ID(), err)
+			_ = broker.Close()
+			client.deregisterBroker(broker)
+
+		default:
+			// some other error, remove that broker and try again
+			Logger.Printf("client/metadata got error from broker %d while fetching metadata: %v\n", broker.ID(), err)
+			_ = broker.Close()
+			client.deregisterBroker(broker)
+		}
+	}
+
+	if broker != nil {
+		Logger.Printf("client/metadata not fetching metadata from broker %s as we would go past the metadata timeout\n", broker.addr)
+		return retry(ErrOutOfBrokers)
+	}
+
+	Logger.Println("client/metadata no available broker to send metadata request to")
+	client.resurrectDeadBrokers()
+	return retry(ErrOutOfBrokers)
+}
+
+// if no fatal error, returns a list of topics that need retrying due to ErrLeaderNotAvailable
+func (client *client) updateMetadata(data *MetadataResponse, allKnownMetaData bool) (retry bool, err error) {
+	if client.Closed() {
+		return
+	}
+
+	client.lock.Lock()
+	defer client.lock.Unlock()
+
+	// For all the brokers we received:
+	// - if it is a new ID, save it
+	// - if it is an existing ID, but the address we have is stale, discard the old one and save it
+	// - otherwise ignore it, replacing our existing one would just bounce the connection
+	for _, broker := range data.Brokers {
+		client.registerBroker(broker)
+	}
+
+	client.controllerID = data.ControllerID
+
+	if allKnownMetaData {
+		client.metadata = make(map[string]map[int32]*PartitionMetadata)
+		client.metadataTopics = make(map[string]none)
+		client.cachedPartitionsResults = make(map[string][maxPartitionIndex][]int32)
+	}
+	for _, topic := range data.Topics {
+		// topics must be added firstly to `metadataTopics` to guarantee that all
+		// requested topics must be recorded to keep them trackable for periodically
+		// metadata refresh.
+		if _, exists := client.metadataTopics[topic.Name]; !exists {
+			client.metadataTopics[topic.Name] = none{}
+		}
+		delete(client.metadata, topic.Name)
+		delete(client.cachedPartitionsResults, topic.Name)
+
+		switch topic.Err {
+		case ErrNoError:
+			// no-op
+		case ErrInvalidTopic, ErrTopicAuthorizationFailed: // don't retry, don't store partial results
+			err = topic.Err
+			continue
+		case ErrUnknownTopicOrPartition: // retry, do not store partial partition results
+			err = topic.Err
+			retry = true
+			continue
+		case ErrLeaderNotAvailable: // retry, but store partial partition results
+			retry = true
+		default: // don't retry, don't store partial results
+			Logger.Printf("Unexpected topic-level metadata error: %s", topic.Err)
+			err = topic.Err
+			continue
+		}
+
+		client.metadata[topic.Name] = make(map[int32]*PartitionMetadata, len(topic.Partitions))
+		for _, partition := range topic.Partitions {
+			client.metadata[topic.Name][partition.ID] = partition
+			if partition.Err == ErrLeaderNotAvailable {
+				retry = true
+			}
+		}
+
+		var partitionCache [maxPartitionIndex][]int32
+		partitionCache[allPartitions] = client.setPartitionCache(topic.Name, allPartitions)
+		partitionCache[writablePartitions] = client.setPartitionCache(topic.Name, writablePartitions)
+		client.cachedPartitionsResults[topic.Name] = partitionCache
+	}
+
+	return
+}
+
+func (client *client) cachedCoordinator(consumerGroup string) *Broker {
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+	if coordinatorID, ok := client.coordinators[consumerGroup]; ok {
+		return client.brokers[coordinatorID]
+	}
+	return nil
+}
+
+func (client *client) cachedController() *Broker {
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+
+	return client.brokers[client.controllerID]
+}
+
+func (client *client) computeBackoff(attemptsRemaining int) time.Duration {
+	if client.conf.Metadata.Retry.BackoffFunc != nil {
+		maxRetries := client.conf.Metadata.Retry.Max
+		retries := maxRetries - attemptsRemaining
+		return client.conf.Metadata.Retry.BackoffFunc(retries, maxRetries)
+	}
+	return client.conf.Metadata.Retry.Backoff
+}
+
+func (client *client) getConsumerMetadata(consumerGroup string, attemptsRemaining int) (*FindCoordinatorResponse, error) {
+	retry := func(err error) (*FindCoordinatorResponse, error) {
+		if attemptsRemaining > 0 {
+			backoff := client.computeBackoff(attemptsRemaining)
+			Logger.Printf("client/coordinator retrying after %dms... (%d attempts remaining)\n", backoff/time.Millisecond, attemptsRemaining)
+			time.Sleep(backoff)
+			return client.getConsumerMetadata(consumerGroup, attemptsRemaining-1)
+		}
+		return nil, err
+	}
+
+	for broker := client.any(); broker != nil; broker = client.any() {
+		Logger.Printf("client/coordinator requesting coordinator for consumergroup %s from %s\n", consumerGroup, broker.Addr())
+
+		request := new(FindCoordinatorRequest)
+		request.CoordinatorKey = consumerGroup
+		request.CoordinatorType = CoordinatorGroup
+
+		response, err := broker.FindCoordinator(request)
+
+		if err != nil {
+			Logger.Printf("client/coordinator request to broker %s failed: %s\n", broker.Addr(), err)
+
+			switch err.(type) {
+			case PacketEncodingError:
+				return nil, err
+			default:
+				_ = broker.Close()
+				client.deregisterBroker(broker)
+				continue
+			}
+		}
+
+		switch response.Err {
+		case ErrNoError:
+			Logger.Printf("client/coordinator coordinator for consumergroup %s is #%d (%s)\n", consumerGroup, response.Coordinator.ID(), response.Coordinator.Addr())
+			return response, nil
+
+		case ErrConsumerCoordinatorNotAvailable:
+			Logger.Printf("client/coordinator coordinator for consumer group %s is not available\n", consumerGroup)
+
+			// This is very ugly, but this scenario will only happen once per cluster.
+			// The __consumer_offsets topic only has to be created one time.
+			// The number of partitions not configurable, but partition 0 should always exist.
+			if _, err := client.Leader("__consumer_offsets", 0); err != nil {
+				Logger.Printf("client/coordinator the __consumer_offsets topic is not initialized completely yet. Waiting 2 seconds...\n")
+				time.Sleep(2 * time.Second)
+			}
+
+			return retry(ErrConsumerCoordinatorNotAvailable)
+		case ErrGroupAuthorizationFailed:
+			Logger.Printf("client was not authorized to access group %s while attempting to find coordinator", consumerGroup)
+			return retry(ErrGroupAuthorizationFailed)
+
+		default:
+			return nil, response.Err
+		}
+	}
+
+	Logger.Println("client/coordinator no available broker to send consumer metadata request to")
+	client.resurrectDeadBrokers()
+	return retry(ErrOutOfBrokers)
+}
+
+// nopCloserClient embeds an existing Client, but disables
+// the Close method (yet all other methods pass
+// through unchanged). This is for use in larger structs
+// where it is undesirable to close the client that was
+// passed in by the caller.
+type nopCloserClient struct {
+	Client
+}
+
+// Close intercepts and purposely does not call the underlying
+// client's Close() method.
+func (ncc *nopCloserClient) Close() error {
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/compress.go b/vendor/github.com/Shopify/sarama/compress.go
new file mode 100644
index 0000000..9247c35
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/compress.go
@@ -0,0 +1,75 @@
+package sarama
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"sync"
+
+	"github.com/eapache/go-xerial-snappy"
+	"github.com/pierrec/lz4"
+)
+
+var (
+	lz4WriterPool = sync.Pool{
+		New: func() interface{} {
+			return lz4.NewWriter(nil)
+		},
+	}
+
+	gzipWriterPool = sync.Pool{
+		New: func() interface{} {
+			return gzip.NewWriter(nil)
+		},
+	}
+)
+
+func compress(cc CompressionCodec, level int, data []byte) ([]byte, error) {
+	switch cc {
+	case CompressionNone:
+		return data, nil
+	case CompressionGZIP:
+		var (
+			err    error
+			buf    bytes.Buffer
+			writer *gzip.Writer
+		)
+		if level != CompressionLevelDefault {
+			writer, err = gzip.NewWriterLevel(&buf, level)
+			if err != nil {
+				return nil, err
+			}
+		} else {
+			writer = gzipWriterPool.Get().(*gzip.Writer)
+			defer gzipWriterPool.Put(writer)
+			writer.Reset(&buf)
+		}
+		if _, err := writer.Write(data); err != nil {
+			return nil, err
+		}
+		if err := writer.Close(); err != nil {
+			return nil, err
+		}
+		return buf.Bytes(), nil
+	case CompressionSnappy:
+		return snappy.Encode(data), nil
+	case CompressionLZ4:
+		writer := lz4WriterPool.Get().(*lz4.Writer)
+		defer lz4WriterPool.Put(writer)
+
+		var buf bytes.Buffer
+		writer.Reset(&buf)
+
+		if _, err := writer.Write(data); err != nil {
+			return nil, err
+		}
+		if err := writer.Close(); err != nil {
+			return nil, err
+		}
+		return buf.Bytes(), nil
+	case CompressionZSTD:
+		return zstdCompress(nil, data)
+	default:
+		return nil, PacketEncodingError{fmt.Sprintf("unsupported compression codec (%d)", cc)}
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/config.go b/vendor/github.com/Shopify/sarama/config.go
new file mode 100644
index 0000000..69c7161
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/config.go
@@ -0,0 +1,703 @@
+package sarama
+
+import (
+	"compress/gzip"
+	"crypto/tls"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"regexp"
+	"time"
+
+	"github.com/rcrowley/go-metrics"
+	"golang.org/x/net/proxy"
+)
+
+const defaultClientID = "sarama"
+
+var validID = regexp.MustCompile(`\A[A-Za-z0-9._-]+\z`)
+
+// Config is used to pass multiple configuration options to Sarama's constructors.
+type Config struct {
+	// Admin is the namespace for ClusterAdmin properties used by the administrative Kafka client.
+	Admin struct {
+		// The maximum duration the administrative Kafka client will wait for ClusterAdmin operations,
+		// including topics, brokers, configurations and ACLs (defaults to 3 seconds).
+		Timeout time.Duration
+	}
+
+	// Net is the namespace for network-level properties used by the Broker, and
+	// shared by the Client/Producer/Consumer.
+	Net struct {
+		// How many outstanding requests a connection is allowed to have before
+		// sending on it blocks (default 5).
+		MaxOpenRequests int
+
+		// All three of the below configurations are similar to the
+		// `socket.timeout.ms` setting in JVM kafka. All of them default
+		// to 30 seconds.
+		DialTimeout  time.Duration // How long to wait for the initial connection.
+		ReadTimeout  time.Duration // How long to wait for a response.
+		WriteTimeout time.Duration // How long to wait for a transmit.
+
+		TLS struct {
+			// Whether or not to use TLS when connecting to the broker
+			// (defaults to false).
+			Enable bool
+			// The TLS configuration to use for secure connections if
+			// enabled (defaults to nil).
+			Config *tls.Config
+		}
+
+		// SASL based authentication with broker. While there are multiple SASL authentication methods
+		// the current implementation is limited to plaintext (SASL/PLAIN) authentication
+		SASL struct {
+			// Whether or not to use SASL authentication when connecting to the broker
+			// (defaults to false).
+			Enable bool
+			// SASLMechanism is the name of the enabled SASL mechanism.
+			// Possible values: OAUTHBEARER, PLAIN (defaults to PLAIN).
+			Mechanism SASLMechanism
+			// Version is the SASL Protocol Version to use
+			// Kafka > 1.x should use V1, except on Azure EventHub which use V0
+			Version int16
+			// Whether or not to send the Kafka SASL handshake first if enabled
+			// (defaults to true). You should only set this to false if you're using
+			// a non-Kafka SASL proxy.
+			Handshake bool
+			//username and password for SASL/PLAIN  or SASL/SCRAM authentication
+			User     string
+			Password string
+			// authz id used for SASL/SCRAM authentication
+			SCRAMAuthzID string
+			// SCRAMClientGeneratorFunc is a generator of a user provided implementation of a SCRAM
+			// client used to perform the SCRAM exchange with the server.
+			SCRAMClientGeneratorFunc func() SCRAMClient
+			// TokenProvider is a user-defined callback for generating
+			// access tokens for SASL/OAUTHBEARER auth. See the
+			// AccessTokenProvider interface docs for proper implementation
+			// guidelines.
+			TokenProvider AccessTokenProvider
+
+			GSSAPI GSSAPIConfig
+		}
+
+		// KeepAlive specifies the keep-alive period for an active network connection.
+		// If zero, keep-alives are disabled. (default is 0: disabled).
+		KeepAlive time.Duration
+
+		// LocalAddr is the local address to use when dialing an
+		// address. The address must be of a compatible type for the
+		// network being dialed.
+		// If nil, a local address is automatically chosen.
+		LocalAddr net.Addr
+
+		Proxy struct {
+			// Whether or not to use proxy when connecting to the broker
+			// (defaults to false).
+			Enable bool
+			// The proxy dialer to use enabled (defaults to nil).
+			Dialer proxy.Dialer
+		}
+	}
+
+	// Metadata is the namespace for metadata management properties used by the
+	// Client, and shared by the Producer/Consumer.
+	Metadata struct {
+		Retry struct {
+			// The total number of times to retry a metadata request when the
+			// cluster is in the middle of a leader election (default 3).
+			Max int
+			// How long to wait for leader election to occur before retrying
+			// (default 250ms). Similar to the JVM's `retry.backoff.ms`.
+			Backoff time.Duration
+			// Called to compute backoff time dynamically. Useful for implementing
+			// more sophisticated backoff strategies. This takes precedence over
+			// `Backoff` if set.
+			BackoffFunc func(retries, maxRetries int) time.Duration
+		}
+		// How frequently to refresh the cluster metadata in the background.
+		// Defaults to 10 minutes. Set to 0 to disable. Similar to
+		// `topic.metadata.refresh.interval.ms` in the JVM version.
+		RefreshFrequency time.Duration
+
+		// Whether to maintain a full set of metadata for all topics, or just
+		// the minimal set that has been necessary so far. The full set is simpler
+		// and usually more convenient, but can take up a substantial amount of
+		// memory if you have many topics and partitions. Defaults to true.
+		Full bool
+
+		// How long to wait for a successful metadata response.
+		// Disabled by default which means a metadata request against an unreachable
+		// cluster (all brokers are unreachable or unresponsive) can take up to
+		// `Net.[Dial|Read]Timeout * BrokerCount * (Metadata.Retry.Max + 1) + Metadata.Retry.Backoff * Metadata.Retry.Max`
+		// to fail.
+		Timeout time.Duration
+	}
+
+	// Producer is the namespace for configuration related to producing messages,
+	// used by the Producer.
+	Producer struct {
+		// The maximum permitted size of a message (defaults to 1000000). Should be
+		// set equal to or smaller than the broker's `message.max.bytes`.
+		MaxMessageBytes int
+		// The level of acknowledgement reliability needed from the broker (defaults
+		// to WaitForLocal). Equivalent to the `request.required.acks` setting of the
+		// JVM producer.
+		RequiredAcks RequiredAcks
+		// The maximum duration the broker will wait the receipt of the number of
+		// RequiredAcks (defaults to 10 seconds). This is only relevant when
+		// RequiredAcks is set to WaitForAll or a number > 1. Only supports
+		// millisecond resolution, nanoseconds will be truncated. Equivalent to
+		// the JVM producer's `request.timeout.ms` setting.
+		Timeout time.Duration
+		// The type of compression to use on messages (defaults to no compression).
+		// Similar to `compression.codec` setting of the JVM producer.
+		Compression CompressionCodec
+		// The level of compression to use on messages. The meaning depends
+		// on the actual compression type used and defaults to default compression
+		// level for the codec.
+		CompressionLevel int
+		// Generates partitioners for choosing the partition to send messages to
+		// (defaults to hashing the message key). Similar to the `partitioner.class`
+		// setting for the JVM producer.
+		Partitioner PartitionerConstructor
+		// If enabled, the producer will ensure that exactly one copy of each message is
+		// written.
+		Idempotent bool
+
+		// Return specifies what channels will be populated. If they are set to true,
+		// you must read from the respective channels to prevent deadlock. If,
+		// however, this config is used to create a `SyncProducer`, both must be set
+		// to true and you shall not read from the channels since the producer does
+		// this internally.
+		Return struct {
+			// If enabled, successfully delivered messages will be returned on the
+			// Successes channel (default disabled).
+			Successes bool
+
+			// If enabled, messages that failed to deliver will be returned on the
+			// Errors channel, including error (default enabled).
+			Errors bool
+		}
+
+		// The following config options control how often messages are batched up and
+		// sent to the broker. By default, messages are sent as fast as possible, and
+		// all messages received while the current batch is in-flight are placed
+		// into the subsequent batch.
+		Flush struct {
+			// The best-effort number of bytes needed to trigger a flush. Use the
+			// global sarama.MaxRequestSize to set a hard upper limit.
+			Bytes int
+			// The best-effort number of messages needed to trigger a flush. Use
+			// `MaxMessages` to set a hard upper limit.
+			Messages int
+			// The best-effort frequency of flushes. Equivalent to
+			// `queue.buffering.max.ms` setting of JVM producer.
+			Frequency time.Duration
+			// The maximum number of messages the producer will send in a single
+			// broker request. Defaults to 0 for unlimited. Similar to
+			// `queue.buffering.max.messages` in the JVM producer.
+			MaxMessages int
+		}
+
+		Retry struct {
+			// The total number of times to retry sending a message (default 3).
+			// Similar to the `message.send.max.retries` setting of the JVM producer.
+			Max int
+			// How long to wait for the cluster to settle between retries
+			// (default 100ms). Similar to the `retry.backoff.ms` setting of the
+			// JVM producer.
+			Backoff time.Duration
+			// Called to compute backoff time dynamically. Useful for implementing
+			// more sophisticated backoff strategies. This takes precedence over
+			// `Backoff` if set.
+			BackoffFunc func(retries, maxRetries int) time.Duration
+		}
+	}
+
+	// Consumer is the namespace for configuration related to consuming messages,
+	// used by the Consumer.
+	Consumer struct {
+
+		// Group is the namespace for configuring consumer group.
+		Group struct {
+			Session struct {
+				// The timeout used to detect consumer failures when using Kafka's group management facility.
+				// The consumer sends periodic heartbeats to indicate its liveness to the broker.
+				// If no heartbeats are received by the broker before the expiration of this session timeout,
+				// then the broker will remove this consumer from the group and initiate a rebalance.
+				// Note that the value must be in the allowable range as configured in the broker configuration
+				// by `group.min.session.timeout.ms` and `group.max.session.timeout.ms` (default 10s)
+				Timeout time.Duration
+			}
+			Heartbeat struct {
+				// The expected time between heartbeats to the consumer coordinator when using Kafka's group
+				// management facilities. Heartbeats are used to ensure that the consumer's session stays active and
+				// to facilitate rebalancing when new consumers join or leave the group.
+				// The value must be set lower than Consumer.Group.Session.Timeout, but typically should be set no
+				// higher than 1/3 of that value.
+				// It can be adjusted even lower to control the expected time for normal rebalances (default 3s)
+				Interval time.Duration
+			}
+			Rebalance struct {
+				// Strategy for allocating topic partitions to members (default BalanceStrategyRange)
+				Strategy BalanceStrategy
+				// The maximum allowed time for each worker to join the group once a rebalance has begun.
+				// This is basically a limit on the amount of time needed for all tasks to flush any pending
+				// data and commit offsets. If the timeout is exceeded, then the worker will be removed from
+				// the group, which will cause offset commit failures (default 60s).
+				Timeout time.Duration
+
+				Retry struct {
+					// When a new consumer joins a consumer group the set of consumers attempt to "rebalance"
+					// the load to assign partitions to each consumer. If the set of consumers changes while
+					// this assignment is taking place the rebalance will fail and retry. This setting controls
+					// the maximum number of attempts before giving up (default 4).
+					Max int
+					// Backoff time between retries during rebalance (default 2s)
+					Backoff time.Duration
+				}
+			}
+			Member struct {
+				// Custom metadata to include when joining the group. The user data for all joined members
+				// can be retrieved by sending a DescribeGroupRequest to the broker that is the
+				// coordinator for the group.
+				UserData []byte
+			}
+		}
+
+		Retry struct {
+			// How long to wait after a failing to read from a partition before
+			// trying again (default 2s).
+			Backoff time.Duration
+			// Called to compute backoff time dynamically. Useful for implementing
+			// more sophisticated backoff strategies. This takes precedence over
+			// `Backoff` if set.
+			BackoffFunc func(retries int) time.Duration
+		}
+
+		// Fetch is the namespace for controlling how many bytes are retrieved by any
+		// given request.
+		Fetch struct {
+			// The minimum number of message bytes to fetch in a request - the broker
+			// will wait until at least this many are available. The default is 1,
+			// as 0 causes the consumer to spin when no messages are available.
+			// Equivalent to the JVM's `fetch.min.bytes`.
+			Min int32
+			// The default number of message bytes to fetch from the broker in each
+			// request (default 1MB). This should be larger than the majority of
+			// your messages, or else the consumer will spend a lot of time
+			// negotiating sizes and not actually consuming. Similar to the JVM's
+			// `fetch.message.max.bytes`.
+			Default int32
+			// The maximum number of message bytes to fetch from the broker in a
+			// single request. Messages larger than this will return
+			// ErrMessageTooLarge and will not be consumable, so you must be sure
+			// this is at least as large as your largest message. Defaults to 0
+			// (no limit). Similar to the JVM's `fetch.message.max.bytes`. The
+			// global `sarama.MaxResponseSize` still applies.
+			Max int32
+		}
+		// The maximum amount of time the broker will wait for Consumer.Fetch.Min
+		// bytes to become available before it returns fewer than that anyways. The
+		// default is 250ms, since 0 causes the consumer to spin when no events are
+		// available. 100-500ms is a reasonable range for most cases. Kafka only
+		// supports precision up to milliseconds; nanoseconds will be truncated.
+		// Equivalent to the JVM's `fetch.wait.max.ms`.
+		MaxWaitTime time.Duration
+
+		// The maximum amount of time the consumer expects a message takes to
+		// process for the user. If writing to the Messages channel takes longer
+		// than this, that partition will stop fetching more messages until it
+		// can proceed again.
+		// Note that, since the Messages channel is buffered, the actual grace time is
+		// (MaxProcessingTime * ChannelBufferSize). Defaults to 100ms.
+		// If a message is not written to the Messages channel between two ticks
+		// of the expiryTicker then a timeout is detected.
+		// Using a ticker instead of a timer to detect timeouts should typically
+		// result in many fewer calls to Timer functions which may result in a
+		// significant performance improvement if many messages are being sent
+		// and timeouts are infrequent.
+		// The disadvantage of using a ticker instead of a timer is that
+		// timeouts will be less accurate. That is, the effective timeout could
+		// be between `MaxProcessingTime` and `2 * MaxProcessingTime`. For
+		// example, if `MaxProcessingTime` is 100ms then a delay of 180ms
+		// between two messages being sent may not be recognized as a timeout.
+		MaxProcessingTime time.Duration
+
+		// Return specifies what channels will be populated. If they are set to true,
+		// you must read from them to prevent deadlock.
+		Return struct {
+			// If enabled, any errors that occurred while consuming are returned on
+			// the Errors channel (default disabled).
+			Errors bool
+		}
+
+		// Offsets specifies configuration for how and when to commit consumed
+		// offsets. This currently requires the manual use of an OffsetManager
+		// but will eventually be automated.
+		Offsets struct {
+			AutoCommit struct {
+				// Whether or not to auto-commit updated offsets back to the broker.
+				// (default enabled).
+				Enable bool
+
+				// How frequently to commit updated offsets. Ineffective unless
+				// auto-commit is enabled (default 1s)
+				Interval time.Duration
+			}
+
+			// The initial offset to use if no offset was previously committed.
+			// Should be OffsetNewest or OffsetOldest. Defaults to OffsetNewest.
+			Initial int64
+
+			// The retention duration for committed offsets. If zero, disabled
+			// (in which case the `offsets.retention.minutes` option on the
+			// broker will be used).  Kafka only supports precision up to
+			// milliseconds; nanoseconds will be truncated. Requires Kafka
+			// broker version 0.9.0 or later.
+			// (default is 0: disabled).
+			Retention time.Duration
+
+			Retry struct {
+				// The total number of times to retry failing commit
+				// requests during OffsetManager shutdown (default 3).
+				Max int
+			}
+		}
+
+		// IsolationLevel support 2 mode:
+		// 	- use `ReadUncommitted` (default) to consume and return all messages in message channel
+		//	- use `ReadCommitted` to hide messages that are part of an aborted transaction
+		IsolationLevel IsolationLevel
+	}
+
+	// A user-provided string sent with every request to the brokers for logging,
+	// debugging, and auditing purposes. Defaults to "sarama", but you should
+	// probably set it to something specific to your application.
+	ClientID string
+	// The number of events to buffer in internal and external channels. This
+	// permits the producer and consumer to continue processing some messages
+	// in the background while user code is working, greatly improving throughput.
+	// Defaults to 256.
+	ChannelBufferSize int
+	// The version of Kafka that Sarama will assume it is running against.
+	// Defaults to the oldest supported stable version. Since Kafka provides
+	// backwards-compatibility, setting it to a version older than you have
+	// will not break anything, although it may prevent you from using the
+	// latest features. Setting it to a version greater than you are actually
+	// running may lead to random breakage.
+	Version KafkaVersion
+	// The registry to define metrics into.
+	// Defaults to a local registry.
+	// If you want to disable metrics gathering, set "metrics.UseNilMetrics" to "true"
+	// prior to starting Sarama.
+	// See Examples on how to use the metrics registry
+	MetricRegistry metrics.Registry
+}
+
+// NewConfig returns a new configuration instance with sane defaults.
+func NewConfig() *Config {
+	c := &Config{}
+
+	c.Admin.Timeout = 3 * time.Second
+
+	c.Net.MaxOpenRequests = 5
+	c.Net.DialTimeout = 30 * time.Second
+	c.Net.ReadTimeout = 30 * time.Second
+	c.Net.WriteTimeout = 30 * time.Second
+	c.Net.SASL.Handshake = true
+	c.Net.SASL.Version = SASLHandshakeV0
+
+	c.Metadata.Retry.Max = 3
+	c.Metadata.Retry.Backoff = 250 * time.Millisecond
+	c.Metadata.RefreshFrequency = 10 * time.Minute
+	c.Metadata.Full = true
+
+	c.Producer.MaxMessageBytes = 1000000
+	c.Producer.RequiredAcks = WaitForLocal
+	c.Producer.Timeout = 10 * time.Second
+	c.Producer.Partitioner = NewHashPartitioner
+	c.Producer.Retry.Max = 3
+	c.Producer.Retry.Backoff = 100 * time.Millisecond
+	c.Producer.Return.Errors = true
+	c.Producer.CompressionLevel = CompressionLevelDefault
+
+	c.Consumer.Fetch.Min = 1
+	c.Consumer.Fetch.Default = 1024 * 1024
+	c.Consumer.Retry.Backoff = 2 * time.Second
+	c.Consumer.MaxWaitTime = 250 * time.Millisecond
+	c.Consumer.MaxProcessingTime = 100 * time.Millisecond
+	c.Consumer.Return.Errors = false
+	c.Consumer.Offsets.AutoCommit.Enable = true
+	c.Consumer.Offsets.AutoCommit.Interval = 1 * time.Second
+	c.Consumer.Offsets.Initial = OffsetNewest
+	c.Consumer.Offsets.Retry.Max = 3
+
+	c.Consumer.Group.Session.Timeout = 10 * time.Second
+	c.Consumer.Group.Heartbeat.Interval = 3 * time.Second
+	c.Consumer.Group.Rebalance.Strategy = BalanceStrategyRange
+	c.Consumer.Group.Rebalance.Timeout = 60 * time.Second
+	c.Consumer.Group.Rebalance.Retry.Max = 4
+	c.Consumer.Group.Rebalance.Retry.Backoff = 2 * time.Second
+
+	c.ClientID = defaultClientID
+	c.ChannelBufferSize = 256
+	c.Version = MinVersion
+	c.MetricRegistry = metrics.NewRegistry()
+
+	return c
+}
+
+// Validate checks a Config instance. It will return a
+// ConfigurationError if the specified values don't make sense.
+func (c *Config) Validate() error {
+	// some configuration values should be warned on but not fail completely, do those first
+	if !c.Net.TLS.Enable && c.Net.TLS.Config != nil {
+		Logger.Println("Net.TLS is disabled but a non-nil configuration was provided.")
+	}
+	if !c.Net.SASL.Enable {
+		if c.Net.SASL.User != "" {
+			Logger.Println("Net.SASL is disabled but a non-empty username was provided.")
+		}
+		if c.Net.SASL.Password != "" {
+			Logger.Println("Net.SASL is disabled but a non-empty password was provided.")
+		}
+	}
+	if c.Producer.RequiredAcks > 1 {
+		Logger.Println("Producer.RequiredAcks > 1 is deprecated and will raise an exception with kafka >= 0.8.2.0.")
+	}
+	if c.Producer.MaxMessageBytes >= int(MaxRequestSize) {
+		Logger.Println("Producer.MaxMessageBytes must be smaller than MaxRequestSize; it will be ignored.")
+	}
+	if c.Producer.Flush.Bytes >= int(MaxRequestSize) {
+		Logger.Println("Producer.Flush.Bytes must be smaller than MaxRequestSize; it will be ignored.")
+	}
+	if (c.Producer.Flush.Bytes > 0 || c.Producer.Flush.Messages > 0) && c.Producer.Flush.Frequency == 0 {
+		Logger.Println("Producer.Flush: Bytes or Messages are set, but Frequency is not; messages may not get flushed.")
+	}
+	if c.Producer.Timeout%time.Millisecond != 0 {
+		Logger.Println("Producer.Timeout only supports millisecond resolution; nanoseconds will be truncated.")
+	}
+	if c.Consumer.MaxWaitTime < 100*time.Millisecond {
+		Logger.Println("Consumer.MaxWaitTime is very low, which can cause high CPU and network usage. See documentation for details.")
+	}
+	if c.Consumer.MaxWaitTime%time.Millisecond != 0 {
+		Logger.Println("Consumer.MaxWaitTime only supports millisecond precision; nanoseconds will be truncated.")
+	}
+	if c.Consumer.Offsets.Retention%time.Millisecond != 0 {
+		Logger.Println("Consumer.Offsets.Retention only supports millisecond precision; nanoseconds will be truncated.")
+	}
+	if c.Consumer.Group.Session.Timeout%time.Millisecond != 0 {
+		Logger.Println("Consumer.Group.Session.Timeout only supports millisecond precision; nanoseconds will be truncated.")
+	}
+	if c.Consumer.Group.Heartbeat.Interval%time.Millisecond != 0 {
+		Logger.Println("Consumer.Group.Heartbeat.Interval only supports millisecond precision; nanoseconds will be truncated.")
+	}
+	if c.Consumer.Group.Rebalance.Timeout%time.Millisecond != 0 {
+		Logger.Println("Consumer.Group.Rebalance.Timeout only supports millisecond precision; nanoseconds will be truncated.")
+	}
+	if c.ClientID == defaultClientID {
+		Logger.Println("ClientID is the default of 'sarama', you should consider setting it to something application-specific.")
+	}
+
+	// validate Net values
+	switch {
+	case c.Net.MaxOpenRequests <= 0:
+		return ConfigurationError("Net.MaxOpenRequests must be > 0")
+	case c.Net.DialTimeout <= 0:
+		return ConfigurationError("Net.DialTimeout must be > 0")
+	case c.Net.ReadTimeout <= 0:
+		return ConfigurationError("Net.ReadTimeout must be > 0")
+	case c.Net.WriteTimeout <= 0:
+		return ConfigurationError("Net.WriteTimeout must be > 0")
+	case c.Net.KeepAlive < 0:
+		return ConfigurationError("Net.KeepAlive must be >= 0")
+	case c.Net.SASL.Enable:
+		if c.Net.SASL.Mechanism == "" {
+			c.Net.SASL.Mechanism = SASLTypePlaintext
+		}
+
+		switch c.Net.SASL.Mechanism {
+		case SASLTypePlaintext:
+			if c.Net.SASL.User == "" {
+				return ConfigurationError("Net.SASL.User must not be empty when SASL is enabled")
+			}
+			if c.Net.SASL.Password == "" {
+				return ConfigurationError("Net.SASL.Password must not be empty when SASL is enabled")
+			}
+		case SASLTypeOAuth:
+			if c.Net.SASL.TokenProvider == nil {
+				return ConfigurationError("An AccessTokenProvider instance must be provided to Net.SASL.TokenProvider")
+			}
+		case SASLTypeSCRAMSHA256, SASLTypeSCRAMSHA512:
+			if c.Net.SASL.User == "" {
+				return ConfigurationError("Net.SASL.User must not be empty when SASL is enabled")
+			}
+			if c.Net.SASL.Password == "" {
+				return ConfigurationError("Net.SASL.Password must not be empty when SASL is enabled")
+			}
+			if c.Net.SASL.SCRAMClientGeneratorFunc == nil {
+				return ConfigurationError("A SCRAMClientGeneratorFunc function must be provided to Net.SASL.SCRAMClientGeneratorFunc")
+			}
+		case SASLTypeGSSAPI:
+			if c.Net.SASL.GSSAPI.ServiceName == "" {
+				return ConfigurationError("Net.SASL.GSSAPI.ServiceName must not be empty when GSS-API mechanism is used")
+			}
+
+			if c.Net.SASL.GSSAPI.AuthType == KRB5_USER_AUTH {
+				if c.Net.SASL.GSSAPI.Password == "" {
+					return ConfigurationError("Net.SASL.GSSAPI.Password must not be empty when GSS-API " +
+						"mechanism is used and Net.SASL.GSSAPI.AuthType = KRB5_USER_AUTH")
+				}
+			} else if c.Net.SASL.GSSAPI.AuthType == KRB5_KEYTAB_AUTH {
+				if c.Net.SASL.GSSAPI.KeyTabPath == "" {
+					return ConfigurationError("Net.SASL.GSSAPI.KeyTabPath must not be empty when GSS-API mechanism is used" +
+						" and  Net.SASL.GSSAPI.AuthType = KRB5_KEYTAB_AUTH")
+				}
+			} else {
+				return ConfigurationError("Net.SASL.GSSAPI.AuthType is invalid. Possible values are KRB5_USER_AUTH and KRB5_KEYTAB_AUTH")
+			}
+			if c.Net.SASL.GSSAPI.KerberosConfigPath == "" {
+				return ConfigurationError("Net.SASL.GSSAPI.KerberosConfigPath must not be empty when GSS-API mechanism is used")
+			}
+			if c.Net.SASL.GSSAPI.Username == "" {
+				return ConfigurationError("Net.SASL.GSSAPI.Username must not be empty when GSS-API mechanism is used")
+			}
+			if c.Net.SASL.GSSAPI.Realm == "" {
+				return ConfigurationError("Net.SASL.GSSAPI.Realm must not be empty when GSS-API mechanism is used")
+			}
+		default:
+			msg := fmt.Sprintf("The SASL mechanism configuration is invalid. Possible values are `%s`, `%s`, `%s`, `%s` and `%s`",
+				SASLTypeOAuth, SASLTypePlaintext, SASLTypeSCRAMSHA256, SASLTypeSCRAMSHA512, SASLTypeGSSAPI)
+			return ConfigurationError(msg)
+		}
+	}
+
+	// validate the Admin values
+	switch {
+	case c.Admin.Timeout <= 0:
+		return ConfigurationError("Admin.Timeout must be > 0")
+	}
+
+	// validate the Metadata values
+	switch {
+	case c.Metadata.Retry.Max < 0:
+		return ConfigurationError("Metadata.Retry.Max must be >= 0")
+	case c.Metadata.Retry.Backoff < 0:
+		return ConfigurationError("Metadata.Retry.Backoff must be >= 0")
+	case c.Metadata.RefreshFrequency < 0:
+		return ConfigurationError("Metadata.RefreshFrequency must be >= 0")
+	}
+
+	// validate the Producer values
+	switch {
+	case c.Producer.MaxMessageBytes <= 0:
+		return ConfigurationError("Producer.MaxMessageBytes must be > 0")
+	case c.Producer.RequiredAcks < -1:
+		return ConfigurationError("Producer.RequiredAcks must be >= -1")
+	case c.Producer.Timeout <= 0:
+		return ConfigurationError("Producer.Timeout must be > 0")
+	case c.Producer.Partitioner == nil:
+		return ConfigurationError("Producer.Partitioner must not be nil")
+	case c.Producer.Flush.Bytes < 0:
+		return ConfigurationError("Producer.Flush.Bytes must be >= 0")
+	case c.Producer.Flush.Messages < 0:
+		return ConfigurationError("Producer.Flush.Messages must be >= 0")
+	case c.Producer.Flush.Frequency < 0:
+		return ConfigurationError("Producer.Flush.Frequency must be >= 0")
+	case c.Producer.Flush.MaxMessages < 0:
+		return ConfigurationError("Producer.Flush.MaxMessages must be >= 0")
+	case c.Producer.Flush.MaxMessages > 0 && c.Producer.Flush.MaxMessages < c.Producer.Flush.Messages:
+		return ConfigurationError("Producer.Flush.MaxMessages must be >= Producer.Flush.Messages when set")
+	case c.Producer.Retry.Max < 0:
+		return ConfigurationError("Producer.Retry.Max must be >= 0")
+	case c.Producer.Retry.Backoff < 0:
+		return ConfigurationError("Producer.Retry.Backoff must be >= 0")
+	}
+
+	if c.Producer.Compression == CompressionLZ4 && !c.Version.IsAtLeast(V0_10_0_0) {
+		return ConfigurationError("lz4 compression requires Version >= V0_10_0_0")
+	}
+
+	if c.Producer.Compression == CompressionGZIP {
+		if c.Producer.CompressionLevel != CompressionLevelDefault {
+			if _, err := gzip.NewWriterLevel(ioutil.Discard, c.Producer.CompressionLevel); err != nil {
+				return ConfigurationError(fmt.Sprintf("gzip compression does not work with level %d: %v", c.Producer.CompressionLevel, err))
+			}
+		}
+	}
+
+	if c.Producer.Idempotent {
+		if !c.Version.IsAtLeast(V0_11_0_0) {
+			return ConfigurationError("Idempotent producer requires Version >= V0_11_0_0")
+		}
+		if c.Producer.Retry.Max == 0 {
+			return ConfigurationError("Idempotent producer requires Producer.Retry.Max >= 1")
+		}
+		if c.Producer.RequiredAcks != WaitForAll {
+			return ConfigurationError("Idempotent producer requires Producer.RequiredAcks to be WaitForAll")
+		}
+		if c.Net.MaxOpenRequests > 1 {
+			return ConfigurationError("Idempotent producer requires Net.MaxOpenRequests to be 1")
+		}
+	}
+
+	// validate the Consumer values
+	switch {
+	case c.Consumer.Fetch.Min <= 0:
+		return ConfigurationError("Consumer.Fetch.Min must be > 0")
+	case c.Consumer.Fetch.Default <= 0:
+		return ConfigurationError("Consumer.Fetch.Default must be > 0")
+	case c.Consumer.Fetch.Max < 0:
+		return ConfigurationError("Consumer.Fetch.Max must be >= 0")
+	case c.Consumer.MaxWaitTime < 1*time.Millisecond:
+		return ConfigurationError("Consumer.MaxWaitTime must be >= 1ms")
+	case c.Consumer.MaxProcessingTime <= 0:
+		return ConfigurationError("Consumer.MaxProcessingTime must be > 0")
+	case c.Consumer.Retry.Backoff < 0:
+		return ConfigurationError("Consumer.Retry.Backoff must be >= 0")
+	case c.Consumer.Offsets.AutoCommit.Interval <= 0:
+		return ConfigurationError("Consumer.Offsets.CommitInterval must be > 0")
+	case c.Consumer.Offsets.Initial != OffsetOldest && c.Consumer.Offsets.Initial != OffsetNewest:
+		return ConfigurationError("Consumer.Offsets.Initial must be OffsetOldest or OffsetNewest")
+	case c.Consumer.Offsets.Retry.Max < 0:
+		return ConfigurationError("Consumer.Offsets.Retry.Max must be >= 0")
+	case c.Consumer.IsolationLevel != ReadUncommitted && c.Consumer.IsolationLevel != ReadCommitted:
+		return ConfigurationError("Consumer.IsolationLevel must be ReadUncommitted or ReadCommitted")
+	}
+
+	// validate IsolationLevel
+	if c.Consumer.IsolationLevel == ReadCommitted && !c.Version.IsAtLeast(V0_11_0_0) {
+		return ConfigurationError("ReadCommitted requires Version >= V0_11_0_0")
+	}
+
+	// validate the Consumer Group values
+	switch {
+	case c.Consumer.Group.Session.Timeout <= 2*time.Millisecond:
+		return ConfigurationError("Consumer.Group.Session.Timeout must be >= 2ms")
+	case c.Consumer.Group.Heartbeat.Interval < 1*time.Millisecond:
+		return ConfigurationError("Consumer.Group.Heartbeat.Interval must be >= 1ms")
+	case c.Consumer.Group.Heartbeat.Interval >= c.Consumer.Group.Session.Timeout:
+		return ConfigurationError("Consumer.Group.Heartbeat.Interval must be < Consumer.Group.Session.Timeout")
+	case c.Consumer.Group.Rebalance.Strategy == nil:
+		return ConfigurationError("Consumer.Group.Rebalance.Strategy must not be empty")
+	case c.Consumer.Group.Rebalance.Timeout <= time.Millisecond:
+		return ConfigurationError("Consumer.Group.Rebalance.Timeout must be >= 1ms")
+	case c.Consumer.Group.Rebalance.Retry.Max < 0:
+		return ConfigurationError("Consumer.Group.Rebalance.Retry.Max must be >= 0")
+	case c.Consumer.Group.Rebalance.Retry.Backoff < 0:
+		return ConfigurationError("Consumer.Group.Rebalance.Retry.Backoff must be >= 0")
+	}
+
+	// validate misc shared values
+	switch {
+	case c.ChannelBufferSize < 0:
+		return ConfigurationError("ChannelBufferSize must be >= 0")
+	case !validID.MatchString(c.ClientID):
+		return ConfigurationError("ClientID is invalid")
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/config_resource_type.go b/vendor/github.com/Shopify/sarama/config_resource_type.go
new file mode 100644
index 0000000..5399d75
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/config_resource_type.go
@@ -0,0 +1,22 @@
+package sarama
+
+//ConfigResourceType is a type for config resource
+type ConfigResourceType int8
+
+// Taken from :
+// https://cwiki.apache.org/confluence/display/KAFKA/KIP-133%3A+Describe+and+Alter+Configs+Admin+APIs#KIP-133:DescribeandAlterConfigsAdminAPIs-WireFormattypes
+
+const (
+	//UnknownResource constant type
+	UnknownResource ConfigResourceType = iota
+	//AnyResource constant type
+	AnyResource
+	//TopicResource constant type
+	TopicResource
+	//GroupResource constant type
+	GroupResource
+	//ClusterResource constant type
+	ClusterResource
+	//BrokerResource constant type
+	BrokerResource
+)
diff --git a/vendor/github.com/Shopify/sarama/consumer.go b/vendor/github.com/Shopify/sarama/consumer.go
new file mode 100644
index 0000000..72c4d7c
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/consumer.go
@@ -0,0 +1,896 @@
+package sarama
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/rcrowley/go-metrics"
+)
+
+// ConsumerMessage encapsulates a Kafka message returned by the consumer.
+type ConsumerMessage struct {
+	Headers        []*RecordHeader // only set if kafka is version 0.11+
+	Timestamp      time.Time       // only set if kafka is version 0.10+, inner message timestamp
+	BlockTimestamp time.Time       // only set if kafka is version 0.10+, outer (compressed) block timestamp
+
+	Key, Value []byte
+	Topic      string
+	Partition  int32
+	Offset     int64
+}
+
+// ConsumerError is what is provided to the user when an error occurs.
+// It wraps an error and includes the topic and partition.
+type ConsumerError struct {
+	Topic     string
+	Partition int32
+	Err       error
+}
+
+func (ce ConsumerError) Error() string {
+	return fmt.Sprintf("kafka: error while consuming %s/%d: %s", ce.Topic, ce.Partition, ce.Err)
+}
+
+// ConsumerErrors is a type that wraps a batch of errors and implements the Error interface.
+// It can be returned from the PartitionConsumer's Close methods to avoid the need to manually drain errors
+// when stopping.
+type ConsumerErrors []*ConsumerError
+
+func (ce ConsumerErrors) Error() string {
+	return fmt.Sprintf("kafka: %d errors while consuming", len(ce))
+}
+
+// Consumer manages PartitionConsumers which process Kafka messages from brokers. You MUST call Close()
+// on a consumer to avoid leaks, it will not be garbage-collected automatically when it passes out of
+// scope.
+type Consumer interface {
+	// Topics returns the set of available topics as retrieved from the cluster
+	// metadata. This method is the same as Client.Topics(), and is provided for
+	// convenience.
+	Topics() ([]string, error)
+
+	// Partitions returns the sorted list of all partition IDs for the given topic.
+	// This method is the same as Client.Partitions(), and is provided for convenience.
+	Partitions(topic string) ([]int32, error)
+
+	// ConsumePartition creates a PartitionConsumer on the given topic/partition with
+	// the given offset. It will return an error if this Consumer is already consuming
+	// on the given topic/partition. Offset can be a literal offset, or OffsetNewest
+	// or OffsetOldest
+	ConsumePartition(topic string, partition int32, offset int64) (PartitionConsumer, error)
+
+	// HighWaterMarks returns the current high water marks for each topic and partition.
+	// Consistency between partitions is not guaranteed since high water marks are updated separately.
+	HighWaterMarks() map[string]map[int32]int64
+
+	// Close shuts down the consumer. It must be called after all child
+	// PartitionConsumers have already been closed.
+	Close() error
+}
+
+type consumer struct {
+	conf            *Config
+	children        map[string]map[int32]*partitionConsumer
+	brokerConsumers map[*Broker]*brokerConsumer
+	client          Client
+	lock            sync.Mutex
+}
+
+// NewConsumer creates a new consumer using the given broker addresses and configuration.
+func NewConsumer(addrs []string, config *Config) (Consumer, error) {
+	client, err := NewClient(addrs, config)
+	if err != nil {
+		return nil, err
+	}
+	return newConsumer(client)
+}
+
+// NewConsumerFromClient creates a new consumer using the given client. It is still
+// necessary to call Close() on the underlying client when shutting down this consumer.
+func NewConsumerFromClient(client Client) (Consumer, error) {
+	// For clients passed in by the client, ensure we don't
+	// call Close() on it.
+	cli := &nopCloserClient{client}
+	return newConsumer(cli)
+}
+
+func newConsumer(client Client) (Consumer, error) {
+	// Check that we are not dealing with a closed Client before processing any other arguments
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	c := &consumer{
+		client:          client,
+		conf:            client.Config(),
+		children:        make(map[string]map[int32]*partitionConsumer),
+		brokerConsumers: make(map[*Broker]*brokerConsumer),
+	}
+
+	return c, nil
+}
+
+func (c *consumer) Close() error {
+	return c.client.Close()
+}
+
+func (c *consumer) Topics() ([]string, error) {
+	return c.client.Topics()
+}
+
+func (c *consumer) Partitions(topic string) ([]int32, error) {
+	return c.client.Partitions(topic)
+}
+
+func (c *consumer) ConsumePartition(topic string, partition int32, offset int64) (PartitionConsumer, error) {
+	child := &partitionConsumer{
+		consumer:  c,
+		conf:      c.conf,
+		topic:     topic,
+		partition: partition,
+		messages:  make(chan *ConsumerMessage, c.conf.ChannelBufferSize),
+		errors:    make(chan *ConsumerError, c.conf.ChannelBufferSize),
+		feeder:    make(chan *FetchResponse, 1),
+		trigger:   make(chan none, 1),
+		dying:     make(chan none),
+		fetchSize: c.conf.Consumer.Fetch.Default,
+	}
+
+	if err := child.chooseStartingOffset(offset); err != nil {
+		return nil, err
+	}
+
+	var leader *Broker
+	var err error
+	if leader, err = c.client.Leader(child.topic, child.partition); err != nil {
+		return nil, err
+	}
+
+	if err := c.addChild(child); err != nil {
+		return nil, err
+	}
+
+	go withRecover(child.dispatcher)
+	go withRecover(child.responseFeeder)
+
+	child.broker = c.refBrokerConsumer(leader)
+	child.broker.input <- child
+
+	return child, nil
+}
+
+func (c *consumer) HighWaterMarks() map[string]map[int32]int64 {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	hwms := make(map[string]map[int32]int64)
+	for topic, p := range c.children {
+		hwm := make(map[int32]int64, len(p))
+		for partition, pc := range p {
+			hwm[partition] = pc.HighWaterMarkOffset()
+		}
+		hwms[topic] = hwm
+	}
+
+	return hwms
+}
+
+func (c *consumer) addChild(child *partitionConsumer) error {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	topicChildren := c.children[child.topic]
+	if topicChildren == nil {
+		topicChildren = make(map[int32]*partitionConsumer)
+		c.children[child.topic] = topicChildren
+	}
+
+	if topicChildren[child.partition] != nil {
+		return ConfigurationError("That topic/partition is already being consumed")
+	}
+
+	topicChildren[child.partition] = child
+	return nil
+}
+
+func (c *consumer) removeChild(child *partitionConsumer) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	delete(c.children[child.topic], child.partition)
+}
+
+func (c *consumer) refBrokerConsumer(broker *Broker) *brokerConsumer {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	bc := c.brokerConsumers[broker]
+	if bc == nil {
+		bc = c.newBrokerConsumer(broker)
+		c.brokerConsumers[broker] = bc
+	}
+
+	bc.refs++
+
+	return bc
+}
+
+func (c *consumer) unrefBrokerConsumer(brokerWorker *brokerConsumer) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	brokerWorker.refs--
+
+	if brokerWorker.refs == 0 {
+		close(brokerWorker.input)
+		if c.brokerConsumers[brokerWorker.broker] == brokerWorker {
+			delete(c.brokerConsumers, brokerWorker.broker)
+		}
+	}
+}
+
+func (c *consumer) abandonBrokerConsumer(brokerWorker *brokerConsumer) {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	delete(c.brokerConsumers, brokerWorker.broker)
+}
+
+// PartitionConsumer
+
+// PartitionConsumer processes Kafka messages from a given topic and partition. You MUST call one of Close() or
+// AsyncClose() on a PartitionConsumer to avoid leaks; it will not be garbage-collected automatically when it passes out
+// of scope.
+//
+// The simplest way of using a PartitionConsumer is to loop over its Messages channel using a for/range
+// loop. The PartitionConsumer will only stop itself in one case: when the offset being consumed is reported
+// as out of range by the brokers. In this case you should decide what you want to do (try a different offset,
+// notify a human, etc) and handle it appropriately. For all other error cases, it will just keep retrying.
+// By default, it logs these errors to sarama.Logger; if you want to be notified directly of all errors, set
+// your config's Consumer.Return.Errors to true and read from the Errors channel, using a select statement
+// or a separate goroutine. Check out the Consumer examples to see implementations of these different approaches.
+//
+// To terminate such a for/range loop while the loop is executing, call AsyncClose. This will kick off the process of
+// consumer tear-down & return immediately. Continue to loop, servicing the Messages channel until the teardown process
+// AsyncClose initiated closes it (thus terminating the for/range loop). If you've already ceased reading Messages, call
+// Close; this will signal the PartitionConsumer's goroutines to begin shutting down (just like AsyncClose), but will
+// also drain the Messages channel, harvest all errors & return them once cleanup has completed.
+type PartitionConsumer interface {
+	// AsyncClose initiates a shutdown of the PartitionConsumer. This method will return immediately, after which you
+	// should continue to service the 'Messages' and 'Errors' channels until they are empty. It is required to call this
+	// function, or Close before a consumer object passes out of scope, as it will otherwise leak memory. You must call
+	// this before calling Close on the underlying client.
+	AsyncClose()
+
+	// Close stops the PartitionConsumer from fetching messages. It will initiate a shutdown just like AsyncClose, drain
+	// the Messages channel, harvest any errors & return them to the caller. Note that if you are continuing to service
+	// the Messages channel when this function is called, you will be competing with Close for messages; consider
+	// calling AsyncClose, instead. It is required to call this function (or AsyncClose) before a consumer object passes
+	// out of scope, as it will otherwise leak memory. You must call this before calling Close on the underlying client.
+	Close() error
+
+	// Messages returns the read channel for the messages that are returned by
+	// the broker.
+	Messages() <-chan *ConsumerMessage
+
+	// Errors returns a read channel of errors that occurred during consuming, if
+	// enabled. By default, errors are logged and not returned over this channel.
+	// If you want to implement any custom error handling, set your config's
+	// Consumer.Return.Errors setting to true, and read from this channel.
+	Errors() <-chan *ConsumerError
+
+	// HighWaterMarkOffset returns the high water mark offset of the partition,
+	// i.e. the offset that will be used for the next message that will be produced.
+	// You can use this to determine how far behind the processing is.
+	HighWaterMarkOffset() int64
+}
+
+type partitionConsumer struct {
+	highWaterMarkOffset int64 // must be at the top of the struct because https://golang.org/pkg/sync/atomic/#pkg-note-BUG
+
+	consumer *consumer
+	conf     *Config
+	broker   *brokerConsumer
+	messages chan *ConsumerMessage
+	errors   chan *ConsumerError
+	feeder   chan *FetchResponse
+
+	trigger, dying chan none
+	closeOnce      sync.Once
+	topic          string
+	partition      int32
+	responseResult error
+	fetchSize      int32
+	offset         int64
+	retries        int32
+}
+
+var errTimedOut = errors.New("timed out feeding messages to the user") // not user-facing
+
+func (child *partitionConsumer) sendError(err error) {
+	cErr := &ConsumerError{
+		Topic:     child.topic,
+		Partition: child.partition,
+		Err:       err,
+	}
+
+	if child.conf.Consumer.Return.Errors {
+		child.errors <- cErr
+	} else {
+		Logger.Println(cErr)
+	}
+}
+
+func (child *partitionConsumer) computeBackoff() time.Duration {
+	if child.conf.Consumer.Retry.BackoffFunc != nil {
+		retries := atomic.AddInt32(&child.retries, 1)
+		return child.conf.Consumer.Retry.BackoffFunc(int(retries))
+	}
+	return child.conf.Consumer.Retry.Backoff
+}
+
+func (child *partitionConsumer) dispatcher() {
+	for range child.trigger {
+		select {
+		case <-child.dying:
+			close(child.trigger)
+		case <-time.After(child.computeBackoff()):
+			if child.broker != nil {
+				child.consumer.unrefBrokerConsumer(child.broker)
+				child.broker = nil
+			}
+
+			Logger.Printf("consumer/%s/%d finding new broker\n", child.topic, child.partition)
+			if err := child.dispatch(); err != nil {
+				child.sendError(err)
+				child.trigger <- none{}
+			}
+		}
+	}
+
+	if child.broker != nil {
+		child.consumer.unrefBrokerConsumer(child.broker)
+	}
+	child.consumer.removeChild(child)
+	close(child.feeder)
+}
+
+func (child *partitionConsumer) dispatch() error {
+	if err := child.consumer.client.RefreshMetadata(child.topic); err != nil {
+		return err
+	}
+
+	var leader *Broker
+	var err error
+	if leader, err = child.consumer.client.Leader(child.topic, child.partition); err != nil {
+		return err
+	}
+
+	child.broker = child.consumer.refBrokerConsumer(leader)
+
+	child.broker.input <- child
+
+	return nil
+}
+
+func (child *partitionConsumer) chooseStartingOffset(offset int64) error {
+	newestOffset, err := child.consumer.client.GetOffset(child.topic, child.partition, OffsetNewest)
+	if err != nil {
+		return err
+	}
+	oldestOffset, err := child.consumer.client.GetOffset(child.topic, child.partition, OffsetOldest)
+	if err != nil {
+		return err
+	}
+
+	switch {
+	case offset == OffsetNewest:
+		child.offset = newestOffset
+	case offset == OffsetOldest:
+		child.offset = oldestOffset
+	case offset >= oldestOffset && offset <= newestOffset:
+		child.offset = offset
+	default:
+		return ErrOffsetOutOfRange
+	}
+
+	return nil
+}
+
+func (child *partitionConsumer) Messages() <-chan *ConsumerMessage {
+	return child.messages
+}
+
+func (child *partitionConsumer) Errors() <-chan *ConsumerError {
+	return child.errors
+}
+
+func (child *partitionConsumer) AsyncClose() {
+	// this triggers whatever broker owns this child to abandon it and close its trigger channel, which causes
+	// the dispatcher to exit its loop, which removes it from the consumer then closes its 'messages' and
+	// 'errors' channel (alternatively, if the child is already at the dispatcher for some reason, that will
+	// also just close itself)
+	child.closeOnce.Do(func() {
+		close(child.dying)
+	})
+}
+
+func (child *partitionConsumer) Close() error {
+	child.AsyncClose()
+
+	var errors ConsumerErrors
+	for err := range child.errors {
+		errors = append(errors, err)
+	}
+
+	if len(errors) > 0 {
+		return errors
+	}
+	return nil
+}
+
+func (child *partitionConsumer) HighWaterMarkOffset() int64 {
+	return atomic.LoadInt64(&child.highWaterMarkOffset)
+}
+
+func (child *partitionConsumer) responseFeeder() {
+	var msgs []*ConsumerMessage
+	expiryTicker := time.NewTicker(child.conf.Consumer.MaxProcessingTime)
+	firstAttempt := true
+
+feederLoop:
+	for response := range child.feeder {
+		msgs, child.responseResult = child.parseResponse(response)
+
+		if child.responseResult == nil {
+			atomic.StoreInt32(&child.retries, 0)
+		}
+
+		for i, msg := range msgs {
+		messageSelect:
+			select {
+			case <-child.dying:
+				child.broker.acks.Done()
+				continue feederLoop
+			case child.messages <- msg:
+				firstAttempt = true
+			case <-expiryTicker.C:
+				if !firstAttempt {
+					child.responseResult = errTimedOut
+					child.broker.acks.Done()
+				remainingLoop:
+					for _, msg = range msgs[i:] {
+						select {
+						case child.messages <- msg:
+						case <-child.dying:
+							break remainingLoop
+						}
+					}
+					child.broker.input <- child
+					continue feederLoop
+				} else {
+					// current message has not been sent, return to select
+					// statement
+					firstAttempt = false
+					goto messageSelect
+				}
+			}
+		}
+
+		child.broker.acks.Done()
+	}
+
+	expiryTicker.Stop()
+	close(child.messages)
+	close(child.errors)
+}
+
+func (child *partitionConsumer) parseMessages(msgSet *MessageSet) ([]*ConsumerMessage, error) {
+	var messages []*ConsumerMessage
+	for _, msgBlock := range msgSet.Messages {
+		for _, msg := range msgBlock.Messages() {
+			offset := msg.Offset
+			timestamp := msg.Msg.Timestamp
+			if msg.Msg.Version >= 1 {
+				baseOffset := msgBlock.Offset - msgBlock.Messages()[len(msgBlock.Messages())-1].Offset
+				offset += baseOffset
+				if msg.Msg.LogAppendTime {
+					timestamp = msgBlock.Msg.Timestamp
+				}
+			}
+			if offset < child.offset {
+				continue
+			}
+			messages = append(messages, &ConsumerMessage{
+				Topic:          child.topic,
+				Partition:      child.partition,
+				Key:            msg.Msg.Key,
+				Value:          msg.Msg.Value,
+				Offset:         offset,
+				Timestamp:      timestamp,
+				BlockTimestamp: msgBlock.Msg.Timestamp,
+			})
+			child.offset = offset + 1
+		}
+	}
+	if len(messages) == 0 {
+		child.offset++
+	}
+	return messages, nil
+}
+
+func (child *partitionConsumer) parseRecords(batch *RecordBatch) ([]*ConsumerMessage, error) {
+	messages := make([]*ConsumerMessage, 0, len(batch.Records))
+
+	for _, rec := range batch.Records {
+		offset := batch.FirstOffset + rec.OffsetDelta
+		if offset < child.offset {
+			continue
+		}
+		timestamp := batch.FirstTimestamp.Add(rec.TimestampDelta)
+		if batch.LogAppendTime {
+			timestamp = batch.MaxTimestamp
+		}
+		messages = append(messages, &ConsumerMessage{
+			Topic:     child.topic,
+			Partition: child.partition,
+			Key:       rec.Key,
+			Value:     rec.Value,
+			Offset:    offset,
+			Timestamp: timestamp,
+			Headers:   rec.Headers,
+		})
+		child.offset = offset + 1
+	}
+	if len(messages) == 0 {
+		child.offset++
+	}
+	return messages, nil
+}
+
+func (child *partitionConsumer) parseResponse(response *FetchResponse) ([]*ConsumerMessage, error) {
+	var (
+		metricRegistry          = child.conf.MetricRegistry
+		consumerBatchSizeMetric metrics.Histogram
+	)
+
+	if metricRegistry != nil {
+		consumerBatchSizeMetric = getOrRegisterHistogram("consumer-batch-size", metricRegistry)
+	}
+
+	// If request was throttled and empty we log and return without error
+	if response.ThrottleTime != time.Duration(0) && len(response.Blocks) == 0 {
+		Logger.Printf(
+			"consumer/broker/%d FetchResponse throttled %v\n",
+			child.broker.broker.ID(), response.ThrottleTime)
+		return nil, nil
+	}
+
+	block := response.GetBlock(child.topic, child.partition)
+	if block == nil {
+		return nil, ErrIncompleteResponse
+	}
+
+	if block.Err != ErrNoError {
+		return nil, block.Err
+	}
+
+	nRecs, err := block.numRecords()
+	if err != nil {
+		return nil, err
+	}
+
+	consumerBatchSizeMetric.Update(int64(nRecs))
+
+	if nRecs == 0 {
+		partialTrailingMessage, err := block.isPartial()
+		if err != nil {
+			return nil, err
+		}
+		// We got no messages. If we got a trailing one then we need to ask for more data.
+		// Otherwise we just poll again and wait for one to be produced...
+		if partialTrailingMessage {
+			if child.conf.Consumer.Fetch.Max > 0 && child.fetchSize == child.conf.Consumer.Fetch.Max {
+				// we can't ask for more data, we've hit the configured limit
+				child.sendError(ErrMessageTooLarge)
+				child.offset++ // skip this one so we can keep processing future messages
+			} else {
+				child.fetchSize *= 2
+				// check int32 overflow
+				if child.fetchSize < 0 {
+					child.fetchSize = math.MaxInt32
+				}
+				if child.conf.Consumer.Fetch.Max > 0 && child.fetchSize > child.conf.Consumer.Fetch.Max {
+					child.fetchSize = child.conf.Consumer.Fetch.Max
+				}
+			}
+		}
+
+		return nil, nil
+	}
+
+	// we got messages, reset our fetch size in case it was increased for a previous request
+	child.fetchSize = child.conf.Consumer.Fetch.Default
+	atomic.StoreInt64(&child.highWaterMarkOffset, block.HighWaterMarkOffset)
+
+	// abortedProducerIDs contains producerID which message should be ignored as uncommitted
+	// - producerID are added when the partitionConsumer iterate over the offset at which an aborted transaction begins (abortedTransaction.FirstOffset)
+	// - producerID are removed when partitionConsumer iterate over an aborted controlRecord, meaning the aborted transaction for this producer is over
+	abortedProducerIDs := make(map[int64]struct{}, len(block.AbortedTransactions))
+	abortedTransactions := block.getAbortedTransactions()
+
+	messages := []*ConsumerMessage{}
+	for _, records := range block.RecordsSet {
+		switch records.recordsType {
+		case legacyRecords:
+			messageSetMessages, err := child.parseMessages(records.MsgSet)
+			if err != nil {
+				return nil, err
+			}
+
+			messages = append(messages, messageSetMessages...)
+		case defaultRecords:
+			// Consume remaining abortedTransaction up to last offset of current batch
+			for _, txn := range abortedTransactions {
+				if txn.FirstOffset > records.RecordBatch.LastOffset() {
+					break
+				}
+				abortedProducerIDs[txn.ProducerID] = struct{}{}
+				// Pop abortedTransactions so that we never add it again
+				abortedTransactions = abortedTransactions[1:]
+			}
+
+			recordBatchMessages, err := child.parseRecords(records.RecordBatch)
+			if err != nil {
+				return nil, err
+			}
+
+			// Parse and commit offset but do not expose messages that are:
+			// - control records
+			// - part of an aborted transaction when set to `ReadCommitted`
+
+			// control record
+			isControl, err := records.isControl()
+			if err != nil {
+				// I don't know why there is this continue in case of error to begin with
+				// Safe bet is to ignore control messages if ReadUncommitted
+				// and block on them in case of error and ReadCommitted
+				if child.conf.Consumer.IsolationLevel == ReadCommitted {
+					return nil, err
+				}
+				continue
+			}
+			if isControl {
+				controlRecord, err := records.getControlRecord()
+				if err != nil {
+					return nil, err
+				}
+
+				if controlRecord.Type == ControlRecordAbort {
+					delete(abortedProducerIDs, records.RecordBatch.ProducerID)
+				}
+				continue
+			}
+
+			// filter aborted transactions
+			if child.conf.Consumer.IsolationLevel == ReadCommitted {
+				_, isAborted := abortedProducerIDs[records.RecordBatch.ProducerID]
+				if records.RecordBatch.IsTransactional && isAborted {
+					continue
+				}
+			}
+
+			messages = append(messages, recordBatchMessages...)
+		default:
+			return nil, fmt.Errorf("unknown records type: %v", records.recordsType)
+		}
+	}
+
+	return messages, nil
+}
+
+type brokerConsumer struct {
+	consumer         *consumer
+	broker           *Broker
+	input            chan *partitionConsumer
+	newSubscriptions chan []*partitionConsumer
+	subscriptions    map[*partitionConsumer]none
+	wait             chan none
+	acks             sync.WaitGroup
+	refs             int
+}
+
+func (c *consumer) newBrokerConsumer(broker *Broker) *brokerConsumer {
+	bc := &brokerConsumer{
+		consumer:         c,
+		broker:           broker,
+		input:            make(chan *partitionConsumer),
+		newSubscriptions: make(chan []*partitionConsumer),
+		wait:             make(chan none),
+		subscriptions:    make(map[*partitionConsumer]none),
+		refs:             0,
+	}
+
+	go withRecover(bc.subscriptionManager)
+	go withRecover(bc.subscriptionConsumer)
+
+	return bc
+}
+
+// The subscriptionManager constantly accepts new subscriptions on `input` (even when the main subscriptionConsumer
+// goroutine is in the middle of a network request) and batches it up. The main worker goroutine picks
+// up a batch of new subscriptions between every network request by reading from `newSubscriptions`, so we give
+// it nil if no new subscriptions are available. We also write to `wait` only when new subscriptions is available,
+// so the main goroutine can block waiting for work if it has none.
+func (bc *brokerConsumer) subscriptionManager() {
+	var buffer []*partitionConsumer
+
+	for {
+		if len(buffer) > 0 {
+			select {
+			case event, ok := <-bc.input:
+				if !ok {
+					goto done
+				}
+				buffer = append(buffer, event)
+			case bc.newSubscriptions <- buffer:
+				buffer = nil
+			case bc.wait <- none{}:
+			}
+		} else {
+			select {
+			case event, ok := <-bc.input:
+				if !ok {
+					goto done
+				}
+				buffer = append(buffer, event)
+			case bc.newSubscriptions <- nil:
+			}
+		}
+	}
+
+done:
+	close(bc.wait)
+	if len(buffer) > 0 {
+		bc.newSubscriptions <- buffer
+	}
+	close(bc.newSubscriptions)
+}
+
+//subscriptionConsumer ensures we will get nil right away if no new subscriptions is available
+func (bc *brokerConsumer) subscriptionConsumer() {
+	<-bc.wait // wait for our first piece of work
+
+	for newSubscriptions := range bc.newSubscriptions {
+		bc.updateSubscriptions(newSubscriptions)
+
+		if len(bc.subscriptions) == 0 {
+			// We're about to be shut down or we're about to receive more subscriptions.
+			// Either way, the signal just hasn't propagated to our goroutine yet.
+			<-bc.wait
+			continue
+		}
+
+		response, err := bc.fetchNewMessages()
+
+		if err != nil {
+			Logger.Printf("consumer/broker/%d disconnecting due to error processing FetchRequest: %s\n", bc.broker.ID(), err)
+			bc.abort(err)
+			return
+		}
+
+		bc.acks.Add(len(bc.subscriptions))
+		for child := range bc.subscriptions {
+			child.feeder <- response
+		}
+		bc.acks.Wait()
+		bc.handleResponses()
+	}
+}
+
+func (bc *brokerConsumer) updateSubscriptions(newSubscriptions []*partitionConsumer) {
+	for _, child := range newSubscriptions {
+		bc.subscriptions[child] = none{}
+		Logger.Printf("consumer/broker/%d added subscription to %s/%d\n", bc.broker.ID(), child.topic, child.partition)
+	}
+
+	for child := range bc.subscriptions {
+		select {
+		case <-child.dying:
+			Logger.Printf("consumer/broker/%d closed dead subscription to %s/%d\n", bc.broker.ID(), child.topic, child.partition)
+			close(child.trigger)
+			delete(bc.subscriptions, child)
+		default:
+			// no-op
+		}
+	}
+}
+
+//handleResponses handles the response codes left for us by our subscriptions, and abandons ones that have been closed
+func (bc *brokerConsumer) handleResponses() {
+	for child := range bc.subscriptions {
+		result := child.responseResult
+		child.responseResult = nil
+
+		switch result {
+		case nil:
+			// no-op
+		case errTimedOut:
+			Logger.Printf("consumer/broker/%d abandoned subscription to %s/%d because consuming was taking too long\n",
+				bc.broker.ID(), child.topic, child.partition)
+			delete(bc.subscriptions, child)
+		case ErrOffsetOutOfRange:
+			// there's no point in retrying this it will just fail the same way again
+			// shut it down and force the user to choose what to do
+			child.sendError(result)
+			Logger.Printf("consumer/%s/%d shutting down because %s\n", child.topic, child.partition, result)
+			close(child.trigger)
+			delete(bc.subscriptions, child)
+		case ErrUnknownTopicOrPartition, ErrNotLeaderForPartition, ErrLeaderNotAvailable, ErrReplicaNotAvailable:
+			// not an error, but does need redispatching
+			Logger.Printf("consumer/broker/%d abandoned subscription to %s/%d because %s\n",
+				bc.broker.ID(), child.topic, child.partition, result)
+			child.trigger <- none{}
+			delete(bc.subscriptions, child)
+		default:
+			// dunno, tell the user and try redispatching
+			child.sendError(result)
+			Logger.Printf("consumer/broker/%d abandoned subscription to %s/%d because %s\n",
+				bc.broker.ID(), child.topic, child.partition, result)
+			child.trigger <- none{}
+			delete(bc.subscriptions, child)
+		}
+	}
+}
+
+func (bc *brokerConsumer) abort(err error) {
+	bc.consumer.abandonBrokerConsumer(bc)
+	_ = bc.broker.Close() // we don't care about the error this might return, we already have one
+
+	for child := range bc.subscriptions {
+		child.sendError(err)
+		child.trigger <- none{}
+	}
+
+	for newSubscriptions := range bc.newSubscriptions {
+		if len(newSubscriptions) == 0 {
+			<-bc.wait
+			continue
+		}
+		for _, child := range newSubscriptions {
+			child.sendError(err)
+			child.trigger <- none{}
+		}
+	}
+}
+
+func (bc *brokerConsumer) fetchNewMessages() (*FetchResponse, error) {
+	request := &FetchRequest{
+		MinBytes:    bc.consumer.conf.Consumer.Fetch.Min,
+		MaxWaitTime: int32(bc.consumer.conf.Consumer.MaxWaitTime / time.Millisecond),
+	}
+	if bc.consumer.conf.Version.IsAtLeast(V0_9_0_0) {
+		request.Version = 1
+	}
+	if bc.consumer.conf.Version.IsAtLeast(V0_10_0_0) {
+		request.Version = 2
+	}
+	if bc.consumer.conf.Version.IsAtLeast(V0_10_1_0) {
+		request.Version = 3
+		request.MaxBytes = MaxResponseSize
+	}
+	if bc.consumer.conf.Version.IsAtLeast(V0_11_0_0) {
+		request.Version = 4
+		request.Isolation = bc.consumer.conf.Consumer.IsolationLevel
+	}
+
+	for child := range bc.subscriptions {
+		request.AddBlock(child.topic, child.partition, child.offset, child.fetchSize)
+	}
+
+	return bc.broker.Fetch(request)
+}
diff --git a/vendor/github.com/Shopify/sarama/consumer_group.go b/vendor/github.com/Shopify/sarama/consumer_group.go
new file mode 100644
index 0000000..b974dd9
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/consumer_group.go
@@ -0,0 +1,873 @@
+package sarama
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sort"
+	"sync"
+	"time"
+)
+
+// ErrClosedConsumerGroup is the error returned when a method is called on a consumer group that has been closed.
+var ErrClosedConsumerGroup = errors.New("kafka: tried to use a consumer group that was closed")
+
+// ConsumerGroup is responsible for dividing up processing of topics and partitions
+// over a collection of processes (the members of the consumer group).
+type ConsumerGroup interface {
+	// Consume joins a cluster of consumers for a given list of topics and
+	// starts a blocking ConsumerGroupSession through the ConsumerGroupHandler.
+	//
+	// The life-cycle of a session is represented by the following steps:
+	//
+	// 1. The consumers join the group (as explained in https://kafka.apache.org/documentation/#intro_consumers)
+	//    and is assigned their "fair share" of partitions, aka 'claims'.
+	// 2. Before processing starts, the handler's Setup() hook is called to notify the user
+	//    of the claims and allow any necessary preparation or alteration of state.
+	// 3. For each of the assigned claims the handler's ConsumeClaim() function is then called
+	//    in a separate goroutine which requires it to be thread-safe. Any state must be carefully protected
+	//    from concurrent reads/writes.
+	// 4. The session will persist until one of the ConsumeClaim() functions exits. This can be either when the
+	//    parent context is cancelled or when a server-side rebalance cycle is initiated.
+	// 5. Once all the ConsumeClaim() loops have exited, the handler's Cleanup() hook is called
+	//    to allow the user to perform any final tasks before a rebalance.
+	// 6. Finally, marked offsets are committed one last time before claims are released.
+	//
+	// Please note, that once a rebalance is triggered, sessions must be completed within
+	// Config.Consumer.Group.Rebalance.Timeout. This means that ConsumeClaim() functions must exit
+	// as quickly as possible to allow time for Cleanup() and the final offset commit. If the timeout
+	// is exceeded, the consumer will be removed from the group by Kafka, which will cause offset
+	// commit failures.
+	Consume(ctx context.Context, topics []string, handler ConsumerGroupHandler) error
+
+	// Errors returns a read channel of errors that occurred during the consumer life-cycle.
+	// By default, errors are logged and not returned over this channel.
+	// If you want to implement any custom error handling, set your config's
+	// Consumer.Return.Errors setting to true, and read from this channel.
+	Errors() <-chan error
+
+	// Close stops the ConsumerGroup and detaches any running sessions. It is required to call
+	// this function before the object passes out of scope, as it will otherwise leak memory.
+	Close() error
+}
+
+type consumerGroup struct {
+	client Client
+
+	config   *Config
+	consumer Consumer
+	groupID  string
+	memberID string
+	errors   chan error
+
+	lock      sync.Mutex
+	closed    chan none
+	closeOnce sync.Once
+
+	userData []byte
+}
+
+// NewConsumerGroup creates a new consumer group the given broker addresses and configuration.
+func NewConsumerGroup(addrs []string, groupID string, config *Config) (ConsumerGroup, error) {
+	client, err := NewClient(addrs, config)
+	if err != nil {
+		return nil, err
+	}
+
+	c, err := newConsumerGroup(groupID, client)
+	if err != nil {
+		_ = client.Close()
+	}
+	return c, err
+}
+
+// NewConsumerGroupFromClient creates a new consumer group using the given client. It is still
+// necessary to call Close() on the underlying client when shutting down this consumer.
+// PLEASE NOTE: consumer groups can only re-use but not share clients.
+func NewConsumerGroupFromClient(groupID string, client Client) (ConsumerGroup, error) {
+	// For clients passed in by the client, ensure we don't
+	// call Close() on it.
+	cli := &nopCloserClient{client}
+	return newConsumerGroup(groupID, cli)
+}
+
+func newConsumerGroup(groupID string, client Client) (ConsumerGroup, error) {
+	config := client.Config()
+	if !config.Version.IsAtLeast(V0_10_2_0) {
+		return nil, ConfigurationError("consumer groups require Version to be >= V0_10_2_0")
+	}
+
+	consumer, err := NewConsumerFromClient(client)
+	if err != nil {
+		return nil, err
+	}
+
+	return &consumerGroup{
+		client:   client,
+		consumer: consumer,
+		config:   config,
+		groupID:  groupID,
+		errors:   make(chan error, config.ChannelBufferSize),
+		closed:   make(chan none),
+	}, nil
+}
+
+// Errors implements ConsumerGroup.
+func (c *consumerGroup) Errors() <-chan error { return c.errors }
+
+// Close implements ConsumerGroup.
+func (c *consumerGroup) Close() (err error) {
+	c.closeOnce.Do(func() {
+		close(c.closed)
+
+		c.lock.Lock()
+		defer c.lock.Unlock()
+
+		// leave group
+		if e := c.leave(); e != nil {
+			err = e
+		}
+
+		// drain errors
+		go func() {
+			close(c.errors)
+		}()
+		for e := range c.errors {
+			err = e
+		}
+
+		if e := c.client.Close(); e != nil {
+			err = e
+		}
+	})
+	return
+}
+
+// Consume implements ConsumerGroup.
+func (c *consumerGroup) Consume(ctx context.Context, topics []string, handler ConsumerGroupHandler) error {
+	// Ensure group is not closed
+	select {
+	case <-c.closed:
+		return ErrClosedConsumerGroup
+	default:
+	}
+
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	// Quick exit when no topics are provided
+	if len(topics) == 0 {
+		return fmt.Errorf("no topics provided")
+	}
+
+	// Refresh metadata for requested topics
+	if err := c.client.RefreshMetadata(topics...); err != nil {
+		return err
+	}
+
+	// Init session
+	sess, err := c.newSession(ctx, topics, handler, c.config.Consumer.Group.Rebalance.Retry.Max)
+	if err == ErrClosedClient {
+		return ErrClosedConsumerGroup
+	} else if err != nil {
+		return err
+	}
+
+	// loop check topic partition numbers changed
+	// will trigger rebalance when any topic partitions number had changed
+	go c.loopCheckPartitionNumbers(topics, sess)
+
+	// Wait for session exit signal
+	<-sess.ctx.Done()
+
+	// Gracefully release session claims
+	return sess.release(true)
+}
+
+func (c *consumerGroup) retryNewSession(ctx context.Context, topics []string, handler ConsumerGroupHandler, retries int, refreshCoordinator bool) (*consumerGroupSession, error) {
+	select {
+	case <-c.closed:
+		return nil, ErrClosedConsumerGroup
+	case <-time.After(c.config.Consumer.Group.Rebalance.Retry.Backoff):
+	}
+
+	if refreshCoordinator {
+		err := c.client.RefreshCoordinator(c.groupID)
+		if err != nil {
+			return c.retryNewSession(ctx, topics, handler, retries, true)
+		}
+	}
+
+	return c.newSession(ctx, topics, handler, retries-1)
+}
+
+func (c *consumerGroup) newSession(ctx context.Context, topics []string, handler ConsumerGroupHandler, retries int) (*consumerGroupSession, error) {
+	coordinator, err := c.client.Coordinator(c.groupID)
+	if err != nil {
+		if retries <= 0 {
+			return nil, err
+		}
+
+		return c.retryNewSession(ctx, topics, handler, retries, true)
+	}
+
+	// Join consumer group
+	join, err := c.joinGroupRequest(coordinator, topics)
+	if err != nil {
+		_ = coordinator.Close()
+		return nil, err
+	}
+	switch join.Err {
+	case ErrNoError:
+		c.memberID = join.MemberId
+	case ErrUnknownMemberId, ErrIllegalGeneration: // reset member ID and retry immediately
+		c.memberID = ""
+		return c.newSession(ctx, topics, handler, retries)
+	case ErrNotCoordinatorForConsumer: // retry after backoff with coordinator refresh
+		if retries <= 0 {
+			return nil, join.Err
+		}
+
+		return c.retryNewSession(ctx, topics, handler, retries, true)
+	case ErrRebalanceInProgress: // retry after backoff
+		if retries <= 0 {
+			return nil, join.Err
+		}
+
+		return c.retryNewSession(ctx, topics, handler, retries, false)
+	default:
+		return nil, join.Err
+	}
+
+	// Prepare distribution plan if we joined as the leader
+	var plan BalanceStrategyPlan
+	if join.LeaderId == join.MemberId {
+		members, err := join.GetMembers()
+		if err != nil {
+			return nil, err
+		}
+
+		plan, err = c.balance(members)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// Sync consumer group
+	sync, err := c.syncGroupRequest(coordinator, plan, join.GenerationId)
+	if err != nil {
+		_ = coordinator.Close()
+		return nil, err
+	}
+	switch sync.Err {
+	case ErrNoError:
+	case ErrUnknownMemberId, ErrIllegalGeneration: // reset member ID and retry immediately
+		c.memberID = ""
+		return c.newSession(ctx, topics, handler, retries)
+	case ErrNotCoordinatorForConsumer: // retry after backoff with coordinator refresh
+		if retries <= 0 {
+			return nil, sync.Err
+		}
+
+		return c.retryNewSession(ctx, topics, handler, retries, true)
+	case ErrRebalanceInProgress: // retry after backoff
+		if retries <= 0 {
+			return nil, sync.Err
+		}
+
+		return c.retryNewSession(ctx, topics, handler, retries, false)
+	default:
+		return nil, sync.Err
+	}
+
+	// Retrieve and sort claims
+	var claims map[string][]int32
+	if len(sync.MemberAssignment) > 0 {
+		members, err := sync.GetMemberAssignment()
+		if err != nil {
+			return nil, err
+		}
+		claims = members.Topics
+		c.userData = members.UserData
+
+		for _, partitions := range claims {
+			sort.Sort(int32Slice(partitions))
+		}
+	}
+
+	return newConsumerGroupSession(ctx, c, claims, join.MemberId, join.GenerationId, handler)
+}
+
+func (c *consumerGroup) joinGroupRequest(coordinator *Broker, topics []string) (*JoinGroupResponse, error) {
+	req := &JoinGroupRequest{
+		GroupId:        c.groupID,
+		MemberId:       c.memberID,
+		SessionTimeout: int32(c.config.Consumer.Group.Session.Timeout / time.Millisecond),
+		ProtocolType:   "consumer",
+	}
+	if c.config.Version.IsAtLeast(V0_10_1_0) {
+		req.Version = 1
+		req.RebalanceTimeout = int32(c.config.Consumer.Group.Rebalance.Timeout / time.Millisecond)
+	}
+
+	// use static user-data if configured, otherwise use consumer-group userdata from the last sync
+	userData := c.config.Consumer.Group.Member.UserData
+	if len(userData) == 0 {
+		userData = c.userData
+	}
+	meta := &ConsumerGroupMemberMetadata{
+		Topics:   topics,
+		UserData: userData,
+	}
+	strategy := c.config.Consumer.Group.Rebalance.Strategy
+	if err := req.AddGroupProtocolMetadata(strategy.Name(), meta); err != nil {
+		return nil, err
+	}
+
+	return coordinator.JoinGroup(req)
+}
+
+func (c *consumerGroup) syncGroupRequest(coordinator *Broker, plan BalanceStrategyPlan, generationID int32) (*SyncGroupResponse, error) {
+	req := &SyncGroupRequest{
+		GroupId:      c.groupID,
+		MemberId:     c.memberID,
+		GenerationId: generationID,
+	}
+	for memberID, topics := range plan {
+		assignment := &ConsumerGroupMemberAssignment{Topics: topics}
+
+		// Include topic assignments in group-assignment userdata for each consumer-group member
+		if c.config.Consumer.Group.Rebalance.Strategy.Name() == StickyBalanceStrategyName {
+			userDataBytes, err := encode(&StickyAssignorUserDataV1{
+				Topics:     topics,
+				Generation: generationID,
+			}, nil)
+			if err != nil {
+				return nil, err
+			}
+			assignment.UserData = userDataBytes
+		}
+		if err := req.AddGroupAssignmentMember(memberID, assignment); err != nil {
+			return nil, err
+		}
+	}
+	return coordinator.SyncGroup(req)
+}
+
+func (c *consumerGroup) heartbeatRequest(coordinator *Broker, memberID string, generationID int32) (*HeartbeatResponse, error) {
+	req := &HeartbeatRequest{
+		GroupId:      c.groupID,
+		MemberId:     memberID,
+		GenerationId: generationID,
+	}
+
+	return coordinator.Heartbeat(req)
+}
+
+func (c *consumerGroup) balance(members map[string]ConsumerGroupMemberMetadata) (BalanceStrategyPlan, error) {
+	topics := make(map[string][]int32)
+	for _, meta := range members {
+		for _, topic := range meta.Topics {
+			topics[topic] = nil
+		}
+	}
+
+	for topic := range topics {
+		partitions, err := c.client.Partitions(topic)
+		if err != nil {
+			return nil, err
+		}
+		topics[topic] = partitions
+	}
+
+	strategy := c.config.Consumer.Group.Rebalance.Strategy
+	return strategy.Plan(members, topics)
+}
+
+// Leaves the cluster, called by Close, protected by lock.
+func (c *consumerGroup) leave() error {
+	if c.memberID == "" {
+		return nil
+	}
+
+	coordinator, err := c.client.Coordinator(c.groupID)
+	if err != nil {
+		return err
+	}
+
+	resp, err := coordinator.LeaveGroup(&LeaveGroupRequest{
+		GroupId:  c.groupID,
+		MemberId: c.memberID,
+	})
+	if err != nil {
+		_ = coordinator.Close()
+		return err
+	}
+
+	// Unset memberID
+	c.memberID = ""
+
+	// Check response
+	switch resp.Err {
+	case ErrRebalanceInProgress, ErrUnknownMemberId, ErrNoError:
+		return nil
+	default:
+		return resp.Err
+	}
+}
+
+func (c *consumerGroup) handleError(err error, topic string, partition int32) {
+	if _, ok := err.(*ConsumerError); !ok && topic != "" && partition > -1 {
+		err = &ConsumerError{
+			Topic:     topic,
+			Partition: partition,
+			Err:       err,
+		}
+	}
+
+	if !c.config.Consumer.Return.Errors {
+		Logger.Println(err)
+		return
+	}
+
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	select {
+	case <-c.closed:
+		//consumer is closed
+		return
+	default:
+	}
+
+	select {
+	case c.errors <- err:
+	default:
+		// no error listener
+	}
+}
+
+func (c *consumerGroup) loopCheckPartitionNumbers(topics []string, session *consumerGroupSession) {
+	pause := time.NewTicker(c.config.Consumer.Group.Heartbeat.Interval * 2)
+	defer session.cancel()
+	defer pause.Stop()
+	var oldTopicToPartitionNum map[string]int
+	var err error
+	if oldTopicToPartitionNum, err = c.topicToPartitionNumbers(topics); err != nil {
+		return
+	}
+	for {
+		if newTopicToPartitionNum, err := c.topicToPartitionNumbers(topics); err != nil {
+			return
+		} else {
+			for topic, num := range oldTopicToPartitionNum {
+				if newTopicToPartitionNum[topic] != num {
+					return // trigger the end of the session on exit
+				}
+			}
+		}
+		select {
+		case <-pause.C:
+		case <-c.closed:
+			return
+		}
+	}
+}
+
+func (c *consumerGroup) topicToPartitionNumbers(topics []string) (map[string]int, error) {
+	if err := c.client.RefreshMetadata(topics...); err != nil {
+		Logger.Printf("Consumer Group refresh metadata failed %v", err)
+		return nil, err
+	}
+	topicToPartitionNum := make(map[string]int, len(topics))
+	for _, topic := range topics {
+		if partitionNum, err := c.client.Partitions(topic); err != nil {
+			Logger.Printf("Consumer Group topic %s get partition number failed %v", topic, err)
+			return nil, err
+		} else {
+			topicToPartitionNum[topic] = len(partitionNum)
+		}
+	}
+	return topicToPartitionNum, nil
+}
+
+// --------------------------------------------------------------------
+
+// ConsumerGroupSession represents a consumer group member session.
+type ConsumerGroupSession interface {
+	// Claims returns information about the claimed partitions by topic.
+	Claims() map[string][]int32
+
+	// MemberID returns the cluster member ID.
+	MemberID() string
+
+	// GenerationID returns the current generation ID.
+	GenerationID() int32
+
+	// MarkOffset marks the provided offset, alongside a metadata string
+	// that represents the state of the partition consumer at that point in time. The
+	// metadata string can be used by another consumer to restore that state, so it
+	// can resume consumption.
+	//
+	// To follow upstream conventions, you are expected to mark the offset of the
+	// next message to read, not the last message read. Thus, when calling `MarkOffset`
+	// you should typically add one to the offset of the last consumed message.
+	//
+	// Note: calling MarkOffset does not necessarily commit the offset to the backend
+	// store immediately for efficiency reasons, and it may never be committed if
+	// your application crashes. This means that you may end up processing the same
+	// message twice, and your processing should ideally be idempotent.
+	MarkOffset(topic string, partition int32, offset int64, metadata string)
+
+	// ResetOffset resets to the provided offset, alongside a metadata string that
+	// represents the state of the partition consumer at that point in time. Reset
+	// acts as a counterpart to MarkOffset, the difference being that it allows to
+	// reset an offset to an earlier or smaller value, where MarkOffset only
+	// allows incrementing the offset. cf MarkOffset for more details.
+	ResetOffset(topic string, partition int32, offset int64, metadata string)
+
+	// MarkMessage marks a message as consumed.
+	MarkMessage(msg *ConsumerMessage, metadata string)
+
+	// Context returns the session context.
+	Context() context.Context
+}
+
+type consumerGroupSession struct {
+	parent       *consumerGroup
+	memberID     string
+	generationID int32
+	handler      ConsumerGroupHandler
+
+	claims  map[string][]int32
+	offsets *offsetManager
+	ctx     context.Context
+	cancel  func()
+
+	waitGroup       sync.WaitGroup
+	releaseOnce     sync.Once
+	hbDying, hbDead chan none
+}
+
+func newConsumerGroupSession(ctx context.Context, parent *consumerGroup, claims map[string][]int32, memberID string, generationID int32, handler ConsumerGroupHandler) (*consumerGroupSession, error) {
+	// init offset manager
+	offsets, err := newOffsetManagerFromClient(parent.groupID, memberID, generationID, parent.client)
+	if err != nil {
+		return nil, err
+	}
+
+	// init context
+	ctx, cancel := context.WithCancel(ctx)
+
+	// init session
+	sess := &consumerGroupSession{
+		parent:       parent,
+		memberID:     memberID,
+		generationID: generationID,
+		handler:      handler,
+		offsets:      offsets,
+		claims:       claims,
+		ctx:          ctx,
+		cancel:       cancel,
+		hbDying:      make(chan none),
+		hbDead:       make(chan none),
+	}
+
+	// start heartbeat loop
+	go sess.heartbeatLoop()
+
+	// create a POM for each claim
+	for topic, partitions := range claims {
+		for _, partition := range partitions {
+			pom, err := offsets.ManagePartition(topic, partition)
+			if err != nil {
+				_ = sess.release(false)
+				return nil, err
+			}
+
+			// handle POM errors
+			go func(topic string, partition int32) {
+				for err := range pom.Errors() {
+					sess.parent.handleError(err, topic, partition)
+				}
+			}(topic, partition)
+		}
+	}
+
+	// perform setup
+	if err := handler.Setup(sess); err != nil {
+		_ = sess.release(true)
+		return nil, err
+	}
+
+	// start consuming
+	for topic, partitions := range claims {
+		for _, partition := range partitions {
+			sess.waitGroup.Add(1)
+
+			go func(topic string, partition int32) {
+				defer sess.waitGroup.Done()
+
+				// cancel the as session as soon as the first
+				// goroutine exits
+				defer sess.cancel()
+
+				// consume a single topic/partition, blocking
+				sess.consume(topic, partition)
+			}(topic, partition)
+		}
+	}
+	return sess, nil
+}
+
+func (s *consumerGroupSession) Claims() map[string][]int32 { return s.claims }
+func (s *consumerGroupSession) MemberID() string           { return s.memberID }
+func (s *consumerGroupSession) GenerationID() int32        { return s.generationID }
+
+func (s *consumerGroupSession) MarkOffset(topic string, partition int32, offset int64, metadata string) {
+	if pom := s.offsets.findPOM(topic, partition); pom != nil {
+		pom.MarkOffset(offset, metadata)
+	}
+}
+
+func (s *consumerGroupSession) ResetOffset(topic string, partition int32, offset int64, metadata string) {
+	if pom := s.offsets.findPOM(topic, partition); pom != nil {
+		pom.ResetOffset(offset, metadata)
+	}
+}
+
+func (s *consumerGroupSession) MarkMessage(msg *ConsumerMessage, metadata string) {
+	s.MarkOffset(msg.Topic, msg.Partition, msg.Offset+1, metadata)
+}
+
+func (s *consumerGroupSession) Context() context.Context {
+	return s.ctx
+}
+
+func (s *consumerGroupSession) consume(topic string, partition int32) {
+	// quick exit if rebalance is due
+	select {
+	case <-s.ctx.Done():
+		return
+	case <-s.parent.closed:
+		return
+	default:
+	}
+
+	// get next offset
+	offset := s.parent.config.Consumer.Offsets.Initial
+	if pom := s.offsets.findPOM(topic, partition); pom != nil {
+		offset, _ = pom.NextOffset()
+	}
+
+	// create new claim
+	claim, err := newConsumerGroupClaim(s, topic, partition, offset)
+	if err != nil {
+		s.parent.handleError(err, topic, partition)
+		return
+	}
+
+	// handle errors
+	go func() {
+		for err := range claim.Errors() {
+			s.parent.handleError(err, topic, partition)
+		}
+	}()
+
+	// trigger close when session is done
+	go func() {
+		select {
+		case <-s.ctx.Done():
+		case <-s.parent.closed:
+		}
+		claim.AsyncClose()
+	}()
+
+	// start processing
+	if err := s.handler.ConsumeClaim(s, claim); err != nil {
+		s.parent.handleError(err, topic, partition)
+	}
+
+	// ensure consumer is closed & drained
+	claim.AsyncClose()
+	for _, err := range claim.waitClosed() {
+		s.parent.handleError(err, topic, partition)
+	}
+}
+
+func (s *consumerGroupSession) release(withCleanup bool) (err error) {
+	// signal release, stop heartbeat
+	s.cancel()
+
+	// wait for consumers to exit
+	s.waitGroup.Wait()
+
+	// perform release
+	s.releaseOnce.Do(func() {
+		if withCleanup {
+			if e := s.handler.Cleanup(s); e != nil {
+				s.parent.handleError(e, "", -1)
+				err = e
+			}
+		}
+
+		if e := s.offsets.Close(); e != nil {
+			err = e
+		}
+
+		close(s.hbDying)
+		<-s.hbDead
+	})
+
+	return
+}
+
+func (s *consumerGroupSession) heartbeatLoop() {
+	defer close(s.hbDead)
+	defer s.cancel() // trigger the end of the session on exit
+
+	pause := time.NewTicker(s.parent.config.Consumer.Group.Heartbeat.Interval)
+	defer pause.Stop()
+
+	retries := s.parent.config.Metadata.Retry.Max
+	for {
+		coordinator, err := s.parent.client.Coordinator(s.parent.groupID)
+		if err != nil {
+			if retries <= 0 {
+				s.parent.handleError(err, "", -1)
+				return
+			}
+
+			select {
+			case <-s.hbDying:
+				return
+			case <-time.After(s.parent.config.Metadata.Retry.Backoff):
+				retries--
+			}
+			continue
+		}
+
+		resp, err := s.parent.heartbeatRequest(coordinator, s.memberID, s.generationID)
+		if err != nil {
+			_ = coordinator.Close()
+
+			if retries <= 0 {
+				s.parent.handleError(err, "", -1)
+				return
+			}
+
+			retries--
+			continue
+		}
+
+		switch resp.Err {
+		case ErrNoError:
+			retries = s.parent.config.Metadata.Retry.Max
+		case ErrRebalanceInProgress, ErrUnknownMemberId, ErrIllegalGeneration:
+			return
+		default:
+			s.parent.handleError(err, "", -1)
+			return
+		}
+
+		select {
+		case <-pause.C:
+		case <-s.hbDying:
+			return
+		}
+	}
+}
+
+// --------------------------------------------------------------------
+
+// ConsumerGroupHandler instances are used to handle individual topic/partition claims.
+// It also provides hooks for your consumer group session life-cycle and allow you to
+// trigger logic before or after the consume loop(s).
+//
+// PLEASE NOTE that handlers are likely be called from several goroutines concurrently,
+// ensure that all state is safely protected against race conditions.
+type ConsumerGroupHandler interface {
+	// Setup is run at the beginning of a new session, before ConsumeClaim.
+	Setup(ConsumerGroupSession) error
+
+	// Cleanup is run at the end of a session, once all ConsumeClaim goroutines have exited
+	// but before the offsets are committed for the very last time.
+	Cleanup(ConsumerGroupSession) error
+
+	// ConsumeClaim must start a consumer loop of ConsumerGroupClaim's Messages().
+	// Once the Messages() channel is closed, the Handler must finish its processing
+	// loop and exit.
+	ConsumeClaim(ConsumerGroupSession, ConsumerGroupClaim) error
+}
+
+// ConsumerGroupClaim processes Kafka messages from a given topic and partition within a consumer group.
+type ConsumerGroupClaim interface {
+	// Topic returns the consumed topic name.
+	Topic() string
+
+	// Partition returns the consumed partition.
+	Partition() int32
+
+	// InitialOffset returns the initial offset that was used as a starting point for this claim.
+	InitialOffset() int64
+
+	// HighWaterMarkOffset returns the high water mark offset of the partition,
+	// i.e. the offset that will be used for the next message that will be produced.
+	// You can use this to determine how far behind the processing is.
+	HighWaterMarkOffset() int64
+
+	// Messages returns the read channel for the messages that are returned by
+	// the broker. The messages channel will be closed when a new rebalance cycle
+	// is due. You must finish processing and mark offsets within
+	// Config.Consumer.Group.Session.Timeout before the topic/partition is eventually
+	// re-assigned to another group member.
+	Messages() <-chan *ConsumerMessage
+}
+
+type consumerGroupClaim struct {
+	topic     string
+	partition int32
+	offset    int64
+	PartitionConsumer
+}
+
+func newConsumerGroupClaim(sess *consumerGroupSession, topic string, partition int32, offset int64) (*consumerGroupClaim, error) {
+	pcm, err := sess.parent.consumer.ConsumePartition(topic, partition, offset)
+	if err == ErrOffsetOutOfRange {
+		offset = sess.parent.config.Consumer.Offsets.Initial
+		pcm, err = sess.parent.consumer.ConsumePartition(topic, partition, offset)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	go func() {
+		for err := range pcm.Errors() {
+			sess.parent.handleError(err, topic, partition)
+		}
+	}()
+
+	return &consumerGroupClaim{
+		topic:             topic,
+		partition:         partition,
+		offset:            offset,
+		PartitionConsumer: pcm,
+	}, nil
+}
+
+func (c *consumerGroupClaim) Topic() string        { return c.topic }
+func (c *consumerGroupClaim) Partition() int32     { return c.partition }
+func (c *consumerGroupClaim) InitialOffset() int64 { return c.offset }
+
+// Drains messages and errors, ensures the claim is fully closed.
+func (c *consumerGroupClaim) waitClosed() (errs ConsumerErrors) {
+	go func() {
+		for range c.Messages() {
+		}
+	}()
+
+	for err := range c.Errors() {
+		errs = append(errs, err)
+	}
+	return
+}
diff --git a/vendor/github.com/Shopify/sarama/consumer_group_members.go b/vendor/github.com/Shopify/sarama/consumer_group_members.go
new file mode 100644
index 0000000..2d02cc3
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/consumer_group_members.go
@@ -0,0 +1,96 @@
+package sarama
+
+//ConsumerGroupMemberMetadata holds the metadata for consumer group
+type ConsumerGroupMemberMetadata struct {
+	Version  int16
+	Topics   []string
+	UserData []byte
+}
+
+func (m *ConsumerGroupMemberMetadata) encode(pe packetEncoder) error {
+	pe.putInt16(m.Version)
+
+	if err := pe.putStringArray(m.Topics); err != nil {
+		return err
+	}
+
+	if err := pe.putBytes(m.UserData); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (m *ConsumerGroupMemberMetadata) decode(pd packetDecoder) (err error) {
+	if m.Version, err = pd.getInt16(); err != nil {
+		return
+	}
+
+	if m.Topics, err = pd.getStringArray(); err != nil {
+		return
+	}
+
+	if m.UserData, err = pd.getBytes(); err != nil {
+		return
+	}
+
+	return nil
+}
+
+//ConsumerGroupMemberAssignment holds the member assignment for a consume group
+type ConsumerGroupMemberAssignment struct {
+	Version  int16
+	Topics   map[string][]int32
+	UserData []byte
+}
+
+func (m *ConsumerGroupMemberAssignment) encode(pe packetEncoder) error {
+	pe.putInt16(m.Version)
+
+	if err := pe.putArrayLength(len(m.Topics)); err != nil {
+		return err
+	}
+
+	for topic, partitions := range m.Topics {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putInt32Array(partitions); err != nil {
+			return err
+		}
+	}
+
+	if err := pe.putBytes(m.UserData); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (m *ConsumerGroupMemberAssignment) decode(pd packetDecoder) (err error) {
+	if m.Version, err = pd.getInt16(); err != nil {
+		return
+	}
+
+	var topicLen int
+	if topicLen, err = pd.getArrayLength(); err != nil {
+		return
+	}
+
+	m.Topics = make(map[string][]int32, topicLen)
+	for i := 0; i < topicLen; i++ {
+		var topic string
+		if topic, err = pd.getString(); err != nil {
+			return
+		}
+		if m.Topics[topic], err = pd.getInt32Array(); err != nil {
+			return
+		}
+	}
+
+	if m.UserData, err = pd.getBytes(); err != nil {
+		return
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/consumer_metadata_request.go b/vendor/github.com/Shopify/sarama/consumer_metadata_request.go
new file mode 100644
index 0000000..a8dcaef
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/consumer_metadata_request.go
@@ -0,0 +1,34 @@
+package sarama
+
+//ConsumerMetadataRequest is used for metadata requests
+type ConsumerMetadataRequest struct {
+	ConsumerGroup string
+}
+
+func (r *ConsumerMetadataRequest) encode(pe packetEncoder) error {
+	tmp := new(FindCoordinatorRequest)
+	tmp.CoordinatorKey = r.ConsumerGroup
+	tmp.CoordinatorType = CoordinatorGroup
+	return tmp.encode(pe)
+}
+
+func (r *ConsumerMetadataRequest) decode(pd packetDecoder, version int16) (err error) {
+	tmp := new(FindCoordinatorRequest)
+	if err := tmp.decode(pd, version); err != nil {
+		return err
+	}
+	r.ConsumerGroup = tmp.CoordinatorKey
+	return nil
+}
+
+func (r *ConsumerMetadataRequest) key() int16 {
+	return 10
+}
+
+func (r *ConsumerMetadataRequest) version() int16 {
+	return 0
+}
+
+func (r *ConsumerMetadataRequest) requiredVersion() KafkaVersion {
+	return V0_8_2_0
+}
diff --git a/vendor/github.com/Shopify/sarama/consumer_metadata_response.go b/vendor/github.com/Shopify/sarama/consumer_metadata_response.go
new file mode 100644
index 0000000..f39a871
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/consumer_metadata_response.go
@@ -0,0 +1,78 @@
+package sarama
+
+import (
+	"net"
+	"strconv"
+)
+
+//ConsumerMetadataResponse holds the response for a consumer group meta data requests
+type ConsumerMetadataResponse struct {
+	Err             KError
+	Coordinator     *Broker
+	CoordinatorID   int32  // deprecated: use Coordinator.ID()
+	CoordinatorHost string // deprecated: use Coordinator.Addr()
+	CoordinatorPort int32  // deprecated: use Coordinator.Addr()
+}
+
+func (r *ConsumerMetadataResponse) decode(pd packetDecoder, version int16) (err error) {
+	tmp := new(FindCoordinatorResponse)
+
+	if err := tmp.decode(pd, version); err != nil {
+		return err
+	}
+
+	r.Err = tmp.Err
+
+	r.Coordinator = tmp.Coordinator
+	if tmp.Coordinator == nil {
+		return nil
+	}
+
+	// this can all go away in 2.0, but we have to fill in deprecated fields to maintain
+	// backwards compatibility
+	host, portstr, err := net.SplitHostPort(r.Coordinator.Addr())
+	if err != nil {
+		return err
+	}
+	port, err := strconv.ParseInt(portstr, 10, 32)
+	if err != nil {
+		return err
+	}
+	r.CoordinatorID = r.Coordinator.ID()
+	r.CoordinatorHost = host
+	r.CoordinatorPort = int32(port)
+
+	return nil
+}
+
+func (r *ConsumerMetadataResponse) encode(pe packetEncoder) error {
+	if r.Coordinator == nil {
+		r.Coordinator = new(Broker)
+		r.Coordinator.id = r.CoordinatorID
+		r.Coordinator.addr = net.JoinHostPort(r.CoordinatorHost, strconv.Itoa(int(r.CoordinatorPort)))
+	}
+
+	tmp := &FindCoordinatorResponse{
+		Version:     0,
+		Err:         r.Err,
+		Coordinator: r.Coordinator,
+	}
+
+	if err := tmp.encode(pe); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *ConsumerMetadataResponse) key() int16 {
+	return 10
+}
+
+func (r *ConsumerMetadataResponse) version() int16 {
+	return 0
+}
+
+func (r *ConsumerMetadataResponse) requiredVersion() KafkaVersion {
+	return V0_8_2_0
+}
diff --git a/vendor/github.com/Shopify/sarama/control_record.go b/vendor/github.com/Shopify/sarama/control_record.go
new file mode 100644
index 0000000..9b75ab5
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/control_record.go
@@ -0,0 +1,72 @@
+package sarama
+
+//ControlRecordType ...
+type ControlRecordType int
+
+const (
+	//ControlRecordAbort is a control record for abort
+	ControlRecordAbort ControlRecordType = iota
+	//ControlRecordCommit is a control record for commit
+	ControlRecordCommit
+	//ControlRecordUnknown is a control record of unknown type
+	ControlRecordUnknown
+)
+
+// Control records are returned as a record by fetchRequest
+// However unlike "normal" records, they mean nothing application wise.
+// They only serve internal logic for supporting transactions.
+type ControlRecord struct {
+	Version          int16
+	CoordinatorEpoch int32
+	Type             ControlRecordType
+}
+
+func (cr *ControlRecord) decode(key, value packetDecoder) error {
+	var err error
+	cr.Version, err = value.getInt16()
+	if err != nil {
+		return err
+	}
+
+	cr.CoordinatorEpoch, err = value.getInt32()
+	if err != nil {
+		return err
+	}
+
+	// There a version for the value part AND the key part. And I have no idea if they are supposed to match or not
+	// Either way, all these version can only be 0 for now
+	cr.Version, err = key.getInt16()
+	if err != nil {
+		return err
+	}
+
+	recordType, err := key.getInt16()
+	if err != nil {
+		return err
+	}
+
+	switch recordType {
+	case 0:
+		cr.Type = ControlRecordAbort
+	case 1:
+		cr.Type = ControlRecordCommit
+	default:
+		// from JAVA implementation:
+		// UNKNOWN is used to indicate a control type which the client is not aware of and should be ignored
+		cr.Type = ControlRecordUnknown
+	}
+	return nil
+}
+
+func (cr *ControlRecord) encode(key, value packetEncoder) {
+	value.putInt16(cr.Version)
+	value.putInt32(cr.CoordinatorEpoch)
+	key.putInt16(cr.Version)
+
+	switch cr.Type {
+	case ControlRecordAbort:
+		key.putInt16(0)
+	case ControlRecordCommit:
+		key.putInt16(1)
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/crc32_field.go b/vendor/github.com/Shopify/sarama/crc32_field.go
new file mode 100644
index 0000000..38189a3
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/crc32_field.go
@@ -0,0 +1,86 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"fmt"
+	"hash/crc32"
+	"sync"
+)
+
+type crcPolynomial int8
+
+const (
+	crcIEEE crcPolynomial = iota
+	crcCastagnoli
+)
+
+var crc32FieldPool = sync.Pool{}
+
+func acquireCrc32Field(polynomial crcPolynomial) *crc32Field {
+	val := crc32FieldPool.Get()
+	if val != nil {
+		c := val.(*crc32Field)
+		c.polynomial = polynomial
+		return c
+	}
+	return newCRC32Field(polynomial)
+}
+
+func releaseCrc32Field(c *crc32Field) {
+	crc32FieldPool.Put(c)
+}
+
+var castagnoliTable = crc32.MakeTable(crc32.Castagnoli)
+
+// crc32Field implements the pushEncoder and pushDecoder interfaces for calculating CRC32s.
+type crc32Field struct {
+	startOffset int
+	polynomial  crcPolynomial
+}
+
+func (c *crc32Field) saveOffset(in int) {
+	c.startOffset = in
+}
+
+func (c *crc32Field) reserveLength() int {
+	return 4
+}
+
+func newCRC32Field(polynomial crcPolynomial) *crc32Field {
+	return &crc32Field{polynomial: polynomial}
+}
+
+func (c *crc32Field) run(curOffset int, buf []byte) error {
+	crc, err := c.crc(curOffset, buf)
+	if err != nil {
+		return err
+	}
+	binary.BigEndian.PutUint32(buf[c.startOffset:], crc)
+	return nil
+}
+
+func (c *crc32Field) check(curOffset int, buf []byte) error {
+	crc, err := c.crc(curOffset, buf)
+	if err != nil {
+		return err
+	}
+
+	expected := binary.BigEndian.Uint32(buf[c.startOffset:])
+	if crc != expected {
+		return PacketDecodingError{fmt.Sprintf("CRC didn't match expected %#x got %#x", expected, crc)}
+	}
+
+	return nil
+}
+func (c *crc32Field) crc(curOffset int, buf []byte) (uint32, error) {
+	var tab *crc32.Table
+	switch c.polynomial {
+	case crcIEEE:
+		tab = crc32.IEEETable
+	case crcCastagnoli:
+		tab = castagnoliTable
+	default:
+		return 0, PacketDecodingError{"invalid CRC type"}
+	}
+	return crc32.Checksum(buf[c.startOffset+4:curOffset], tab), nil
+}
diff --git a/vendor/github.com/Shopify/sarama/create_partitions_request.go b/vendor/github.com/Shopify/sarama/create_partitions_request.go
new file mode 100644
index 0000000..af321e9
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/create_partitions_request.go
@@ -0,0 +1,121 @@
+package sarama
+
+import "time"
+
+type CreatePartitionsRequest struct {
+	TopicPartitions map[string]*TopicPartition
+	Timeout         time.Duration
+	ValidateOnly    bool
+}
+
+func (c *CreatePartitionsRequest) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(c.TopicPartitions)); err != nil {
+		return err
+	}
+
+	for topic, partition := range c.TopicPartitions {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := partition.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	pe.putInt32(int32(c.Timeout / time.Millisecond))
+
+	pe.putBool(c.ValidateOnly)
+
+	return nil
+}
+
+func (c *CreatePartitionsRequest) decode(pd packetDecoder, version int16) (err error) {
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	c.TopicPartitions = make(map[string]*TopicPartition, n)
+	for i := 0; i < n; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		c.TopicPartitions[topic] = new(TopicPartition)
+		if err := c.TopicPartitions[topic].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	timeout, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	c.Timeout = time.Duration(timeout) * time.Millisecond
+
+	if c.ValidateOnly, err = pd.getBool(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *CreatePartitionsRequest) key() int16 {
+	return 37
+}
+
+func (r *CreatePartitionsRequest) version() int16 {
+	return 0
+}
+
+func (r *CreatePartitionsRequest) requiredVersion() KafkaVersion {
+	return V1_0_0_0
+}
+
+type TopicPartition struct {
+	Count      int32
+	Assignment [][]int32
+}
+
+func (t *TopicPartition) encode(pe packetEncoder) error {
+	pe.putInt32(t.Count)
+
+	if len(t.Assignment) == 0 {
+		pe.putInt32(-1)
+		return nil
+	}
+
+	if err := pe.putArrayLength(len(t.Assignment)); err != nil {
+		return err
+	}
+
+	for _, assign := range t.Assignment {
+		if err := pe.putInt32Array(assign); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (t *TopicPartition) decode(pd packetDecoder, version int16) (err error) {
+	if t.Count, err = pd.getInt32(); err != nil {
+		return err
+	}
+
+	n, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	if n <= 0 {
+		return nil
+	}
+	t.Assignment = make([][]int32, n)
+
+	for i := 0; i < int(n); i++ {
+		if t.Assignment[i], err = pd.getInt32Array(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/create_partitions_response.go b/vendor/github.com/Shopify/sarama/create_partitions_response.go
new file mode 100644
index 0000000..bb18204
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/create_partitions_response.go
@@ -0,0 +1,105 @@
+package sarama
+
+import (
+	"fmt"
+	"time"
+)
+
+type CreatePartitionsResponse struct {
+	ThrottleTime         time.Duration
+	TopicPartitionErrors map[string]*TopicPartitionError
+}
+
+func (c *CreatePartitionsResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(c.ThrottleTime / time.Millisecond))
+	if err := pe.putArrayLength(len(c.TopicPartitionErrors)); err != nil {
+		return err
+	}
+
+	for topic, partitionError := range c.TopicPartitionErrors {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := partitionError.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *CreatePartitionsResponse) decode(pd packetDecoder, version int16) (err error) {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	c.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	c.TopicPartitionErrors = make(map[string]*TopicPartitionError, n)
+	for i := 0; i < n; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		c.TopicPartitionErrors[topic] = new(TopicPartitionError)
+		if err := c.TopicPartitionErrors[topic].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *CreatePartitionsResponse) key() int16 {
+	return 37
+}
+
+func (r *CreatePartitionsResponse) version() int16 {
+	return 0
+}
+
+func (r *CreatePartitionsResponse) requiredVersion() KafkaVersion {
+	return V1_0_0_0
+}
+
+type TopicPartitionError struct {
+	Err    KError
+	ErrMsg *string
+}
+
+func (t *TopicPartitionError) Error() string {
+	text := t.Err.Error()
+	if t.ErrMsg != nil {
+		text = fmt.Sprintf("%s - %s", text, *t.ErrMsg)
+	}
+	return text
+}
+
+func (t *TopicPartitionError) encode(pe packetEncoder) error {
+	pe.putInt16(int16(t.Err))
+
+	if err := pe.putNullableString(t.ErrMsg); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (t *TopicPartitionError) decode(pd packetDecoder, version int16) (err error) {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	t.Err = KError(kerr)
+
+	if t.ErrMsg, err = pd.getNullableString(); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/create_topics_request.go b/vendor/github.com/Shopify/sarama/create_topics_request.go
new file mode 100644
index 0000000..709c0a4
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/create_topics_request.go
@@ -0,0 +1,174 @@
+package sarama
+
+import (
+	"time"
+)
+
+type CreateTopicsRequest struct {
+	Version int16
+
+	TopicDetails map[string]*TopicDetail
+	Timeout      time.Duration
+	ValidateOnly bool
+}
+
+func (c *CreateTopicsRequest) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(c.TopicDetails)); err != nil {
+		return err
+	}
+	for topic, detail := range c.TopicDetails {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := detail.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	pe.putInt32(int32(c.Timeout / time.Millisecond))
+
+	if c.Version >= 1 {
+		pe.putBool(c.ValidateOnly)
+	}
+
+	return nil
+}
+
+func (c *CreateTopicsRequest) decode(pd packetDecoder, version int16) (err error) {
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	c.TopicDetails = make(map[string]*TopicDetail, n)
+
+	for i := 0; i < n; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		c.TopicDetails[topic] = new(TopicDetail)
+		if err = c.TopicDetails[topic].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	timeout, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	c.Timeout = time.Duration(timeout) * time.Millisecond
+
+	if version >= 1 {
+		c.ValidateOnly, err = pd.getBool()
+		if err != nil {
+			return err
+		}
+
+		c.Version = version
+	}
+
+	return nil
+}
+
+func (c *CreateTopicsRequest) key() int16 {
+	return 19
+}
+
+func (c *CreateTopicsRequest) version() int16 {
+	return c.Version
+}
+
+func (c *CreateTopicsRequest) requiredVersion() KafkaVersion {
+	switch c.Version {
+	case 2:
+		return V1_0_0_0
+	case 1:
+		return V0_11_0_0
+	default:
+		return V0_10_1_0
+	}
+}
+
+type TopicDetail struct {
+	NumPartitions     int32
+	ReplicationFactor int16
+	ReplicaAssignment map[int32][]int32
+	ConfigEntries     map[string]*string
+}
+
+func (t *TopicDetail) encode(pe packetEncoder) error {
+	pe.putInt32(t.NumPartitions)
+	pe.putInt16(t.ReplicationFactor)
+
+	if err := pe.putArrayLength(len(t.ReplicaAssignment)); err != nil {
+		return err
+	}
+	for partition, assignment := range t.ReplicaAssignment {
+		pe.putInt32(partition)
+		if err := pe.putInt32Array(assignment); err != nil {
+			return err
+		}
+	}
+
+	if err := pe.putArrayLength(len(t.ConfigEntries)); err != nil {
+		return err
+	}
+	for configKey, configValue := range t.ConfigEntries {
+		if err := pe.putString(configKey); err != nil {
+			return err
+		}
+		if err := pe.putNullableString(configValue); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (t *TopicDetail) decode(pd packetDecoder, version int16) (err error) {
+	if t.NumPartitions, err = pd.getInt32(); err != nil {
+		return err
+	}
+	if t.ReplicationFactor, err = pd.getInt16(); err != nil {
+		return err
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	if n > 0 {
+		t.ReplicaAssignment = make(map[int32][]int32, n)
+		for i := 0; i < n; i++ {
+			replica, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+			if t.ReplicaAssignment[replica], err = pd.getInt32Array(); err != nil {
+				return err
+			}
+		}
+	}
+
+	n, err = pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	if n > 0 {
+		t.ConfigEntries = make(map[string]*string, n)
+		for i := 0; i < n; i++ {
+			configKey, err := pd.getString()
+			if err != nil {
+				return err
+			}
+			if t.ConfigEntries[configKey], err = pd.getNullableString(); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/create_topics_response.go b/vendor/github.com/Shopify/sarama/create_topics_response.go
new file mode 100644
index 0000000..a493e02
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/create_topics_response.go
@@ -0,0 +1,123 @@
+package sarama
+
+import (
+	"fmt"
+	"time"
+)
+
+type CreateTopicsResponse struct {
+	Version      int16
+	ThrottleTime time.Duration
+	TopicErrors  map[string]*TopicError
+}
+
+func (c *CreateTopicsResponse) encode(pe packetEncoder) error {
+	if c.Version >= 2 {
+		pe.putInt32(int32(c.ThrottleTime / time.Millisecond))
+	}
+
+	if err := pe.putArrayLength(len(c.TopicErrors)); err != nil {
+		return err
+	}
+	for topic, topicError := range c.TopicErrors {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := topicError.encode(pe, c.Version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *CreateTopicsResponse) decode(pd packetDecoder, version int16) (err error) {
+	c.Version = version
+
+	if version >= 2 {
+		throttleTime, err := pd.getInt32()
+		if err != nil {
+			return err
+		}
+		c.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	c.TopicErrors = make(map[string]*TopicError, n)
+	for i := 0; i < n; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		c.TopicErrors[topic] = new(TopicError)
+		if err := c.TopicErrors[topic].decode(pd, version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *CreateTopicsResponse) key() int16 {
+	return 19
+}
+
+func (c *CreateTopicsResponse) version() int16 {
+	return c.Version
+}
+
+func (c *CreateTopicsResponse) requiredVersion() KafkaVersion {
+	switch c.Version {
+	case 2:
+		return V1_0_0_0
+	case 1:
+		return V0_11_0_0
+	default:
+		return V0_10_1_0
+	}
+}
+
+type TopicError struct {
+	Err    KError
+	ErrMsg *string
+}
+
+func (t *TopicError) Error() string {
+	text := t.Err.Error()
+	if t.ErrMsg != nil {
+		text = fmt.Sprintf("%s - %s", text, *t.ErrMsg)
+	}
+	return text
+}
+
+func (t *TopicError) encode(pe packetEncoder, version int16) error {
+	pe.putInt16(int16(t.Err))
+
+	if version >= 1 {
+		if err := pe.putNullableString(t.ErrMsg); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (t *TopicError) decode(pd packetDecoder, version int16) (err error) {
+	kErr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	t.Err = KError(kErr)
+
+	if version >= 1 {
+		if t.ErrMsg, err = pd.getNullableString(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/decompress.go b/vendor/github.com/Shopify/sarama/decompress.go
new file mode 100644
index 0000000..eaccbfc
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/decompress.go
@@ -0,0 +1,63 @@
+package sarama
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"io/ioutil"
+	"sync"
+
+	"github.com/eapache/go-xerial-snappy"
+	"github.com/pierrec/lz4"
+)
+
+var (
+	lz4ReaderPool = sync.Pool{
+		New: func() interface{} {
+			return lz4.NewReader(nil)
+		},
+	}
+
+	gzipReaderPool sync.Pool
+)
+
+func decompress(cc CompressionCodec, data []byte) ([]byte, error) {
+	switch cc {
+	case CompressionNone:
+		return data, nil
+	case CompressionGZIP:
+		var (
+			err        error
+			reader     *gzip.Reader
+			readerIntf = gzipReaderPool.Get()
+		)
+		if readerIntf != nil {
+			reader = readerIntf.(*gzip.Reader)
+		} else {
+			reader, err = gzip.NewReader(bytes.NewReader(data))
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		defer gzipReaderPool.Put(reader)
+
+		if err := reader.Reset(bytes.NewReader(data)); err != nil {
+			return nil, err
+		}
+
+		return ioutil.ReadAll(reader)
+	case CompressionSnappy:
+		return snappy.Decode(data)
+	case CompressionLZ4:
+		reader := lz4ReaderPool.Get().(*lz4.Reader)
+		defer lz4ReaderPool.Put(reader)
+
+		reader.Reset(bytes.NewReader(data))
+		return ioutil.ReadAll(reader)
+	case CompressionZSTD:
+		return zstdDecompress(nil, data)
+	default:
+		return nil, PacketDecodingError{fmt.Sprintf("invalid compression specified (%d)", cc)}
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/delete_groups_request.go b/vendor/github.com/Shopify/sarama/delete_groups_request.go
new file mode 100644
index 0000000..305a324
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/delete_groups_request.go
@@ -0,0 +1,30 @@
+package sarama
+
+type DeleteGroupsRequest struct {
+	Groups []string
+}
+
+func (r *DeleteGroupsRequest) encode(pe packetEncoder) error {
+	return pe.putStringArray(r.Groups)
+}
+
+func (r *DeleteGroupsRequest) decode(pd packetDecoder, version int16) (err error) {
+	r.Groups, err = pd.getStringArray()
+	return
+}
+
+func (r *DeleteGroupsRequest) key() int16 {
+	return 42
+}
+
+func (r *DeleteGroupsRequest) version() int16 {
+	return 0
+}
+
+func (r *DeleteGroupsRequest) requiredVersion() KafkaVersion {
+	return V1_1_0_0
+}
+
+func (r *DeleteGroupsRequest) AddGroup(group string) {
+	r.Groups = append(r.Groups, group)
+}
diff --git a/vendor/github.com/Shopify/sarama/delete_groups_response.go b/vendor/github.com/Shopify/sarama/delete_groups_response.go
new file mode 100644
index 0000000..c067ebb
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/delete_groups_response.go
@@ -0,0 +1,70 @@
+package sarama
+
+import (
+	"time"
+)
+
+type DeleteGroupsResponse struct {
+	ThrottleTime    time.Duration
+	GroupErrorCodes map[string]KError
+}
+
+func (r *DeleteGroupsResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(r.ThrottleTime / time.Millisecond))
+
+	if err := pe.putArrayLength(len(r.GroupErrorCodes)); err != nil {
+		return err
+	}
+	for groupID, errorCode := range r.GroupErrorCodes {
+		if err := pe.putString(groupID); err != nil {
+			return err
+		}
+		pe.putInt16(int16(errorCode))
+	}
+
+	return nil
+}
+
+func (r *DeleteGroupsResponse) decode(pd packetDecoder, version int16) error {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	r.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if n == 0 {
+		return nil
+	}
+
+	r.GroupErrorCodes = make(map[string]KError, n)
+	for i := 0; i < n; i++ {
+		groupID, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		errorCode, err := pd.getInt16()
+		if err != nil {
+			return err
+		}
+
+		r.GroupErrorCodes[groupID] = KError(errorCode)
+	}
+
+	return nil
+}
+
+func (r *DeleteGroupsResponse) key() int16 {
+	return 42
+}
+
+func (r *DeleteGroupsResponse) version() int16 {
+	return 0
+}
+
+func (r *DeleteGroupsResponse) requiredVersion() KafkaVersion {
+	return V1_1_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/delete_records_request.go b/vendor/github.com/Shopify/sarama/delete_records_request.go
new file mode 100644
index 0000000..93efafd
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/delete_records_request.go
@@ -0,0 +1,126 @@
+package sarama
+
+import (
+	"sort"
+	"time"
+)
+
+// request message format is:
+// [topic] timeout(int32)
+// where topic is:
+//  name(string) [partition]
+// where partition is:
+//  id(int32) offset(int64)
+
+type DeleteRecordsRequest struct {
+	Topics  map[string]*DeleteRecordsRequestTopic
+	Timeout time.Duration
+}
+
+func (d *DeleteRecordsRequest) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(d.Topics)); err != nil {
+		return err
+	}
+	keys := make([]string, 0, len(d.Topics))
+	for topic := range d.Topics {
+		keys = append(keys, topic)
+	}
+	sort.Strings(keys)
+	for _, topic := range keys {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := d.Topics[topic].encode(pe); err != nil {
+			return err
+		}
+	}
+	pe.putInt32(int32(d.Timeout / time.Millisecond))
+
+	return nil
+}
+
+func (d *DeleteRecordsRequest) decode(pd packetDecoder, version int16) error {
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	if n > 0 {
+		d.Topics = make(map[string]*DeleteRecordsRequestTopic, n)
+		for i := 0; i < n; i++ {
+			topic, err := pd.getString()
+			if err != nil {
+				return err
+			}
+			details := new(DeleteRecordsRequestTopic)
+			if err = details.decode(pd, version); err != nil {
+				return err
+			}
+			d.Topics[topic] = details
+		}
+	}
+
+	timeout, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	d.Timeout = time.Duration(timeout) * time.Millisecond
+
+	return nil
+}
+
+func (d *DeleteRecordsRequest) key() int16 {
+	return 21
+}
+
+func (d *DeleteRecordsRequest) version() int16 {
+	return 0
+}
+
+func (d *DeleteRecordsRequest) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
+
+type DeleteRecordsRequestTopic struct {
+	PartitionOffsets map[int32]int64 // partition => offset
+}
+
+func (t *DeleteRecordsRequestTopic) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(t.PartitionOffsets)); err != nil {
+		return err
+	}
+	keys := make([]int32, 0, len(t.PartitionOffsets))
+	for partition := range t.PartitionOffsets {
+		keys = append(keys, partition)
+	}
+	sort.Slice(keys, func(i, j int) bool { return keys[i] < keys[j] })
+	for _, partition := range keys {
+		pe.putInt32(partition)
+		pe.putInt64(t.PartitionOffsets[partition])
+	}
+	return nil
+}
+
+func (t *DeleteRecordsRequestTopic) decode(pd packetDecoder, version int16) error {
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	if n > 0 {
+		t.PartitionOffsets = make(map[int32]int64, n)
+		for i := 0; i < n; i++ {
+			partition, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+			offset, err := pd.getInt64()
+			if err != nil {
+				return err
+			}
+			t.PartitionOffsets[partition] = offset
+		}
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/delete_records_response.go b/vendor/github.com/Shopify/sarama/delete_records_response.go
new file mode 100644
index 0000000..733a58b
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/delete_records_response.go
@@ -0,0 +1,158 @@
+package sarama
+
+import (
+	"sort"
+	"time"
+)
+
+// response message format is:
+// throttleMs(int32) [topic]
+// where topic is:
+//  name(string) [partition]
+// where partition is:
+//  id(int32) low_watermark(int64) error_code(int16)
+
+type DeleteRecordsResponse struct {
+	Version      int16
+	ThrottleTime time.Duration
+	Topics       map[string]*DeleteRecordsResponseTopic
+}
+
+func (d *DeleteRecordsResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(d.ThrottleTime / time.Millisecond))
+
+	if err := pe.putArrayLength(len(d.Topics)); err != nil {
+		return err
+	}
+	keys := make([]string, 0, len(d.Topics))
+	for topic := range d.Topics {
+		keys = append(keys, topic)
+	}
+	sort.Strings(keys)
+	for _, topic := range keys {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := d.Topics[topic].encode(pe); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (d *DeleteRecordsResponse) decode(pd packetDecoder, version int16) error {
+	d.Version = version
+
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	d.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	if n > 0 {
+		d.Topics = make(map[string]*DeleteRecordsResponseTopic, n)
+		for i := 0; i < n; i++ {
+			topic, err := pd.getString()
+			if err != nil {
+				return err
+			}
+			details := new(DeleteRecordsResponseTopic)
+			if err = details.decode(pd, version); err != nil {
+				return err
+			}
+			d.Topics[topic] = details
+		}
+	}
+
+	return nil
+}
+
+func (d *DeleteRecordsResponse) key() int16 {
+	return 21
+}
+
+func (d *DeleteRecordsResponse) version() int16 {
+	return 0
+}
+
+func (d *DeleteRecordsResponse) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
+
+type DeleteRecordsResponseTopic struct {
+	Partitions map[int32]*DeleteRecordsResponsePartition
+}
+
+func (t *DeleteRecordsResponseTopic) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(t.Partitions)); err != nil {
+		return err
+	}
+	keys := make([]int32, 0, len(t.Partitions))
+	for partition := range t.Partitions {
+		keys = append(keys, partition)
+	}
+	sort.Slice(keys, func(i, j int) bool { return keys[i] < keys[j] })
+	for _, partition := range keys {
+		pe.putInt32(partition)
+		if err := t.Partitions[partition].encode(pe); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (t *DeleteRecordsResponseTopic) decode(pd packetDecoder, version int16) error {
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	if n > 0 {
+		t.Partitions = make(map[int32]*DeleteRecordsResponsePartition, n)
+		for i := 0; i < n; i++ {
+			partition, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+			details := new(DeleteRecordsResponsePartition)
+			if err = details.decode(pd, version); err != nil {
+				return err
+			}
+			t.Partitions[partition] = details
+		}
+	}
+
+	return nil
+}
+
+type DeleteRecordsResponsePartition struct {
+	LowWatermark int64
+	Err          KError
+}
+
+func (t *DeleteRecordsResponsePartition) encode(pe packetEncoder) error {
+	pe.putInt64(t.LowWatermark)
+	pe.putInt16(int16(t.Err))
+	return nil
+}
+
+func (t *DeleteRecordsResponsePartition) decode(pd packetDecoder, version int16) error {
+	lowWatermark, err := pd.getInt64()
+	if err != nil {
+		return err
+	}
+	t.LowWatermark = lowWatermark
+
+	kErr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	t.Err = KError(kErr)
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/delete_topics_request.go b/vendor/github.com/Shopify/sarama/delete_topics_request.go
new file mode 100644
index 0000000..911f67d
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/delete_topics_request.go
@@ -0,0 +1,48 @@
+package sarama
+
+import "time"
+
+type DeleteTopicsRequest struct {
+	Version int16
+	Topics  []string
+	Timeout time.Duration
+}
+
+func (d *DeleteTopicsRequest) encode(pe packetEncoder) error {
+	if err := pe.putStringArray(d.Topics); err != nil {
+		return err
+	}
+	pe.putInt32(int32(d.Timeout / time.Millisecond))
+
+	return nil
+}
+
+func (d *DeleteTopicsRequest) decode(pd packetDecoder, version int16) (err error) {
+	if d.Topics, err = pd.getStringArray(); err != nil {
+		return err
+	}
+	timeout, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	d.Timeout = time.Duration(timeout) * time.Millisecond
+	d.Version = version
+	return nil
+}
+
+func (d *DeleteTopicsRequest) key() int16 {
+	return 20
+}
+
+func (d *DeleteTopicsRequest) version() int16 {
+	return d.Version
+}
+
+func (d *DeleteTopicsRequest) requiredVersion() KafkaVersion {
+	switch d.Version {
+	case 1:
+		return V0_11_0_0
+	default:
+		return V0_10_1_0
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/delete_topics_response.go b/vendor/github.com/Shopify/sarama/delete_topics_response.go
new file mode 100644
index 0000000..3422546
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/delete_topics_response.go
@@ -0,0 +1,78 @@
+package sarama
+
+import "time"
+
+type DeleteTopicsResponse struct {
+	Version         int16
+	ThrottleTime    time.Duration
+	TopicErrorCodes map[string]KError
+}
+
+func (d *DeleteTopicsResponse) encode(pe packetEncoder) error {
+	if d.Version >= 1 {
+		pe.putInt32(int32(d.ThrottleTime / time.Millisecond))
+	}
+
+	if err := pe.putArrayLength(len(d.TopicErrorCodes)); err != nil {
+		return err
+	}
+	for topic, errorCode := range d.TopicErrorCodes {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		pe.putInt16(int16(errorCode))
+	}
+
+	return nil
+}
+
+func (d *DeleteTopicsResponse) decode(pd packetDecoder, version int16) (err error) {
+	if version >= 1 {
+		throttleTime, err := pd.getInt32()
+		if err != nil {
+			return err
+		}
+		d.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+		d.Version = version
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	d.TopicErrorCodes = make(map[string]KError, n)
+
+	for i := 0; i < n; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		errorCode, err := pd.getInt16()
+		if err != nil {
+			return err
+		}
+
+		d.TopicErrorCodes[topic] = KError(errorCode)
+	}
+
+	return nil
+}
+
+func (d *DeleteTopicsResponse) key() int16 {
+	return 20
+}
+
+func (d *DeleteTopicsResponse) version() int16 {
+	return d.Version
+}
+
+func (d *DeleteTopicsResponse) requiredVersion() KafkaVersion {
+	switch d.Version {
+	case 1:
+		return V0_11_0_0
+	default:
+		return V0_10_1_0
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/describe_configs_request.go b/vendor/github.com/Shopify/sarama/describe_configs_request.go
new file mode 100644
index 0000000..ccb587b
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/describe_configs_request.go
@@ -0,0 +1,112 @@
+package sarama
+
+type DescribeConfigsRequest struct {
+	Version         int16
+	Resources       []*ConfigResource
+	IncludeSynonyms bool
+}
+
+type ConfigResource struct {
+	Type        ConfigResourceType
+	Name        string
+	ConfigNames []string
+}
+
+func (r *DescribeConfigsRequest) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(r.Resources)); err != nil {
+		return err
+	}
+
+	for _, c := range r.Resources {
+		pe.putInt8(int8(c.Type))
+		if err := pe.putString(c.Name); err != nil {
+			return err
+		}
+
+		if len(c.ConfigNames) == 0 {
+			pe.putInt32(-1)
+			continue
+		}
+		if err := pe.putStringArray(c.ConfigNames); err != nil {
+			return err
+		}
+	}
+
+	if r.Version >= 1 {
+		pe.putBool(r.IncludeSynonyms)
+	}
+
+	return nil
+}
+
+func (r *DescribeConfigsRequest) decode(pd packetDecoder, version int16) (err error) {
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Resources = make([]*ConfigResource, n)
+
+	for i := 0; i < n; i++ {
+		r.Resources[i] = &ConfigResource{}
+		t, err := pd.getInt8()
+		if err != nil {
+			return err
+		}
+		r.Resources[i].Type = ConfigResourceType(t)
+		name, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		r.Resources[i].Name = name
+
+		confLength, err := pd.getArrayLength()
+
+		if err != nil {
+			return err
+		}
+
+		if confLength == -1 {
+			continue
+		}
+
+		cfnames := make([]string, confLength)
+		for i := 0; i < confLength; i++ {
+			s, err := pd.getString()
+			if err != nil {
+				return err
+			}
+			cfnames[i] = s
+		}
+		r.Resources[i].ConfigNames = cfnames
+	}
+	r.Version = version
+	if r.Version >= 1 {
+		b, err := pd.getBool()
+		if err != nil {
+			return err
+		}
+		r.IncludeSynonyms = b
+	}
+
+	return nil
+}
+
+func (r *DescribeConfigsRequest) key() int16 {
+	return 32
+}
+
+func (r *DescribeConfigsRequest) version() int16 {
+	return r.Version
+}
+
+func (r *DescribeConfigsRequest) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V1_1_0_0
+	case 2:
+		return V2_0_0_0
+	default:
+		return V0_11_0_0
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/describe_configs_response.go b/vendor/github.com/Shopify/sarama/describe_configs_response.go
new file mode 100644
index 0000000..5737232
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/describe_configs_response.go
@@ -0,0 +1,320 @@
+package sarama
+
+import (
+	"fmt"
+	"time"
+)
+
+type ConfigSource int8
+
+func (s ConfigSource) String() string {
+	switch s {
+	case SourceUnknown:
+		return "Unknown"
+	case SourceTopic:
+		return "Topic"
+	case SourceDynamicBroker:
+		return "DynamicBroker"
+	case SourceDynamicDefaultBroker:
+		return "DynamicDefaultBroker"
+	case SourceStaticBroker:
+		return "StaticBroker"
+	case SourceDefault:
+		return "Default"
+	}
+	return fmt.Sprintf("Source Invalid: %d", int(s))
+}
+
+const (
+	SourceUnknown ConfigSource = iota
+	SourceTopic
+	SourceDynamicBroker
+	SourceDynamicDefaultBroker
+	SourceStaticBroker
+	SourceDefault
+)
+
+type DescribeConfigsResponse struct {
+	Version      int16
+	ThrottleTime time.Duration
+	Resources    []*ResourceResponse
+}
+
+type ResourceResponse struct {
+	ErrorCode int16
+	ErrorMsg  string
+	Type      ConfigResourceType
+	Name      string
+	Configs   []*ConfigEntry
+}
+
+type ConfigEntry struct {
+	Name      string
+	Value     string
+	ReadOnly  bool
+	Default   bool
+	Source    ConfigSource
+	Sensitive bool
+	Synonyms  []*ConfigSynonym
+}
+
+type ConfigSynonym struct {
+	ConfigName  string
+	ConfigValue string
+	Source      ConfigSource
+}
+
+func (r *DescribeConfigsResponse) encode(pe packetEncoder) (err error) {
+	pe.putInt32(int32(r.ThrottleTime / time.Millisecond))
+	if err = pe.putArrayLength(len(r.Resources)); err != nil {
+		return err
+	}
+
+	for _, c := range r.Resources {
+		if err = c.encode(pe, r.Version); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *DescribeConfigsResponse) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	r.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Resources = make([]*ResourceResponse, n)
+	for i := 0; i < n; i++ {
+		rr := &ResourceResponse{}
+		if err := rr.decode(pd, version); err != nil {
+			return err
+		}
+		r.Resources[i] = rr
+	}
+
+	return nil
+}
+
+func (r *DescribeConfigsResponse) key() int16 {
+	return 32
+}
+
+func (r *DescribeConfigsResponse) version() int16 {
+	return r.Version
+}
+
+func (r *DescribeConfigsResponse) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V1_0_0_0
+	case 2:
+		return V2_0_0_0
+	default:
+		return V0_11_0_0
+	}
+}
+
+func (r *ResourceResponse) encode(pe packetEncoder, version int16) (err error) {
+	pe.putInt16(r.ErrorCode)
+
+	if err = pe.putString(r.ErrorMsg); err != nil {
+		return err
+	}
+
+	pe.putInt8(int8(r.Type))
+
+	if err = pe.putString(r.Name); err != nil {
+		return err
+	}
+
+	if err = pe.putArrayLength(len(r.Configs)); err != nil {
+		return err
+	}
+
+	for _, c := range r.Configs {
+		if err = c.encode(pe, version); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (r *ResourceResponse) decode(pd packetDecoder, version int16) (err error) {
+	ec, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	r.ErrorCode = ec
+
+	em, err := pd.getString()
+	if err != nil {
+		return err
+	}
+	r.ErrorMsg = em
+
+	t, err := pd.getInt8()
+	if err != nil {
+		return err
+	}
+	r.Type = ConfigResourceType(t)
+
+	name, err := pd.getString()
+	if err != nil {
+		return err
+	}
+	r.Name = name
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Configs = make([]*ConfigEntry, n)
+	for i := 0; i < n; i++ {
+		c := &ConfigEntry{}
+		if err := c.decode(pd, version); err != nil {
+			return err
+		}
+		r.Configs[i] = c
+	}
+	return nil
+}
+
+func (r *ConfigEntry) encode(pe packetEncoder, version int16) (err error) {
+	if err = pe.putString(r.Name); err != nil {
+		return err
+	}
+
+	if err = pe.putString(r.Value); err != nil {
+		return err
+	}
+
+	pe.putBool(r.ReadOnly)
+
+	if version <= 0 {
+		pe.putBool(r.Default)
+		pe.putBool(r.Sensitive)
+	} else {
+		pe.putInt8(int8(r.Source))
+		pe.putBool(r.Sensitive)
+
+		if err := pe.putArrayLength(len(r.Synonyms)); err != nil {
+			return err
+		}
+		for _, c := range r.Synonyms {
+			if err = c.encode(pe, version); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+//https://cwiki.apache.org/confluence/display/KAFKA/KIP-226+-+Dynamic+Broker+Configuration
+func (r *ConfigEntry) decode(pd packetDecoder, version int16) (err error) {
+	if version == 0 {
+		r.Source = SourceUnknown
+	}
+	name, err := pd.getString()
+	if err != nil {
+		return err
+	}
+	r.Name = name
+
+	value, err := pd.getString()
+	if err != nil {
+		return err
+	}
+	r.Value = value
+
+	read, err := pd.getBool()
+	if err != nil {
+		return err
+	}
+	r.ReadOnly = read
+
+	if version == 0 {
+		defaultB, err := pd.getBool()
+		if err != nil {
+			return err
+		}
+		r.Default = defaultB
+	} else {
+		source, err := pd.getInt8()
+		if err != nil {
+			return err
+		}
+		r.Source = ConfigSource(source)
+	}
+
+	sensitive, err := pd.getBool()
+	if err != nil {
+		return err
+	}
+	r.Sensitive = sensitive
+
+	if version > 0 {
+		n, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+		r.Synonyms = make([]*ConfigSynonym, n)
+
+		for i := 0; i < n; i++ {
+			s := &ConfigSynonym{}
+			if err := s.decode(pd, version); err != nil {
+				return err
+			}
+			r.Synonyms[i] = s
+		}
+
+	}
+	return nil
+}
+
+func (c *ConfigSynonym) encode(pe packetEncoder, version int16) (err error) {
+	err = pe.putString(c.ConfigName)
+	if err != nil {
+		return err
+	}
+
+	err = pe.putString(c.ConfigValue)
+	if err != nil {
+		return err
+	}
+
+	pe.putInt8(int8(c.Source))
+
+	return nil
+}
+
+func (c *ConfigSynonym) decode(pd packetDecoder, version int16) error {
+	name, err := pd.getString()
+	if err != nil {
+		return nil
+	}
+	c.ConfigName = name
+
+	value, err := pd.getString()
+	if err != nil {
+		return nil
+	}
+	c.ConfigValue = value
+
+	source, err := pd.getInt8()
+	if err != nil {
+		return nil
+	}
+	c.Source = ConfigSource(source)
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/describe_groups_request.go b/vendor/github.com/Shopify/sarama/describe_groups_request.go
new file mode 100644
index 0000000..1fb3567
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/describe_groups_request.go
@@ -0,0 +1,30 @@
+package sarama
+
+type DescribeGroupsRequest struct {
+	Groups []string
+}
+
+func (r *DescribeGroupsRequest) encode(pe packetEncoder) error {
+	return pe.putStringArray(r.Groups)
+}
+
+func (r *DescribeGroupsRequest) decode(pd packetDecoder, version int16) (err error) {
+	r.Groups, err = pd.getStringArray()
+	return
+}
+
+func (r *DescribeGroupsRequest) key() int16 {
+	return 15
+}
+
+func (r *DescribeGroupsRequest) version() int16 {
+	return 0
+}
+
+func (r *DescribeGroupsRequest) requiredVersion() KafkaVersion {
+	return V0_9_0_0
+}
+
+func (r *DescribeGroupsRequest) AddGroup(group string) {
+	r.Groups = append(r.Groups, group)
+}
diff --git a/vendor/github.com/Shopify/sarama/describe_groups_response.go b/vendor/github.com/Shopify/sarama/describe_groups_response.go
new file mode 100644
index 0000000..542b3a9
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/describe_groups_response.go
@@ -0,0 +1,187 @@
+package sarama
+
+type DescribeGroupsResponse struct {
+	Groups []*GroupDescription
+}
+
+func (r *DescribeGroupsResponse) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(r.Groups)); err != nil {
+		return err
+	}
+
+	for _, groupDescription := range r.Groups {
+		if err := groupDescription.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *DescribeGroupsResponse) decode(pd packetDecoder, version int16) (err error) {
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Groups = make([]*GroupDescription, n)
+	for i := 0; i < n; i++ {
+		r.Groups[i] = new(GroupDescription)
+		if err := r.Groups[i].decode(pd); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *DescribeGroupsResponse) key() int16 {
+	return 15
+}
+
+func (r *DescribeGroupsResponse) version() int16 {
+	return 0
+}
+
+func (r *DescribeGroupsResponse) requiredVersion() KafkaVersion {
+	return V0_9_0_0
+}
+
+type GroupDescription struct {
+	Err          KError
+	GroupId      string
+	State        string
+	ProtocolType string
+	Protocol     string
+	Members      map[string]*GroupMemberDescription
+}
+
+func (gd *GroupDescription) encode(pe packetEncoder) error {
+	pe.putInt16(int16(gd.Err))
+
+	if err := pe.putString(gd.GroupId); err != nil {
+		return err
+	}
+	if err := pe.putString(gd.State); err != nil {
+		return err
+	}
+	if err := pe.putString(gd.ProtocolType); err != nil {
+		return err
+	}
+	if err := pe.putString(gd.Protocol); err != nil {
+		return err
+	}
+
+	if err := pe.putArrayLength(len(gd.Members)); err != nil {
+		return err
+	}
+
+	for memberId, groupMemberDescription := range gd.Members {
+		if err := pe.putString(memberId); err != nil {
+			return err
+		}
+		if err := groupMemberDescription.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (gd *GroupDescription) decode(pd packetDecoder) (err error) {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+
+	gd.Err = KError(kerr)
+
+	if gd.GroupId, err = pd.getString(); err != nil {
+		return
+	}
+	if gd.State, err = pd.getString(); err != nil {
+		return
+	}
+	if gd.ProtocolType, err = pd.getString(); err != nil {
+		return
+	}
+	if gd.Protocol, err = pd.getString(); err != nil {
+		return
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if n == 0 {
+		return nil
+	}
+
+	gd.Members = make(map[string]*GroupMemberDescription)
+	for i := 0; i < n; i++ {
+		memberId, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		gd.Members[memberId] = new(GroupMemberDescription)
+		if err := gd.Members[memberId].decode(pd); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+type GroupMemberDescription struct {
+	ClientId         string
+	ClientHost       string
+	MemberMetadata   []byte
+	MemberAssignment []byte
+}
+
+func (gmd *GroupMemberDescription) encode(pe packetEncoder) error {
+	if err := pe.putString(gmd.ClientId); err != nil {
+		return err
+	}
+	if err := pe.putString(gmd.ClientHost); err != nil {
+		return err
+	}
+	if err := pe.putBytes(gmd.MemberMetadata); err != nil {
+		return err
+	}
+	if err := pe.putBytes(gmd.MemberAssignment); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (gmd *GroupMemberDescription) decode(pd packetDecoder) (err error) {
+	if gmd.ClientId, err = pd.getString(); err != nil {
+		return
+	}
+	if gmd.ClientHost, err = pd.getString(); err != nil {
+		return
+	}
+	if gmd.MemberMetadata, err = pd.getBytes(); err != nil {
+		return
+	}
+	if gmd.MemberAssignment, err = pd.getBytes(); err != nil {
+		return
+	}
+
+	return nil
+}
+
+func (gmd *GroupMemberDescription) GetMemberAssignment() (*ConsumerGroupMemberAssignment, error) {
+	assignment := new(ConsumerGroupMemberAssignment)
+	err := decode(gmd.MemberAssignment, assignment)
+	return assignment, err
+}
+
+func (gmd *GroupMemberDescription) GetMemberMetadata() (*ConsumerGroupMemberMetadata, error) {
+	metadata := new(ConsumerGroupMemberMetadata)
+	err := decode(gmd.MemberMetadata, metadata)
+	return metadata, err
+}
diff --git a/vendor/github.com/Shopify/sarama/describe_log_dirs_request.go b/vendor/github.com/Shopify/sarama/describe_log_dirs_request.go
new file mode 100644
index 0000000..cb1e781
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/describe_log_dirs_request.go
@@ -0,0 +1,83 @@
+package sarama
+
+// DescribeLogDirsRequest is a describe request to get partitions' log size
+type DescribeLogDirsRequest struct {
+	// Version 0 and 1 are equal
+	// The version number is bumped to indicate that on quota violation brokers send out responses before throttling.
+	Version int16
+
+	// If this is an empty array, all topics will be queried
+	DescribeTopics []DescribeLogDirsRequestTopic
+}
+
+// DescribeLogDirsRequestTopic is a describe request about the log dir of one or more partitions within a Topic
+type DescribeLogDirsRequestTopic struct {
+	Topic        string
+	PartitionIDs []int32
+}
+
+func (r *DescribeLogDirsRequest) encode(pe packetEncoder) error {
+	length := len(r.DescribeTopics)
+	if length == 0 {
+		// In order to query all topics we must send null
+		length = -1
+	}
+
+	if err := pe.putArrayLength(length); err != nil {
+		return err
+	}
+
+	for _, d := range r.DescribeTopics {
+		if err := pe.putString(d.Topic); err != nil {
+			return err
+		}
+
+		if err := pe.putInt32Array(d.PartitionIDs); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *DescribeLogDirsRequest) decode(pd packetDecoder, version int16) error {
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if n == -1 {
+		n = 0
+	}
+
+	topics := make([]DescribeLogDirsRequestTopic, n)
+	for i := 0; i < n; i++ {
+		topics[i] = DescribeLogDirsRequestTopic{}
+
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		topics[i].Topic = topic
+
+		pIDs, err := pd.getInt32Array()
+		if err != nil {
+			return err
+		}
+		topics[i].PartitionIDs = pIDs
+	}
+	r.DescribeTopics = topics
+
+	return nil
+}
+
+func (r *DescribeLogDirsRequest) key() int16 {
+	return 35
+}
+
+func (r *DescribeLogDirsRequest) version() int16 {
+	return r.Version
+}
+
+func (r *DescribeLogDirsRequest) requiredVersion() KafkaVersion {
+	return V1_0_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/describe_log_dirs_response.go b/vendor/github.com/Shopify/sarama/describe_log_dirs_response.go
new file mode 100644
index 0000000..d207312
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/describe_log_dirs_response.go
@@ -0,0 +1,219 @@
+package sarama
+
+import "time"
+
+type DescribeLogDirsResponse struct {
+	ThrottleTime time.Duration
+
+	// Version 0 and 1 are equal
+	// The version number is bumped to indicate that on quota violation brokers send out responses before throttling.
+	Version int16
+
+	LogDirs []DescribeLogDirsResponseDirMetadata
+}
+
+func (r *DescribeLogDirsResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(r.ThrottleTime / time.Millisecond))
+
+	if err := pe.putArrayLength(len(r.LogDirs)); err != nil {
+		return err
+	}
+
+	for _, dir := range r.LogDirs {
+		if err := dir.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *DescribeLogDirsResponse) decode(pd packetDecoder, version int16) error {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	r.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	// Decode array of DescribeLogDirsResponseDirMetadata
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.LogDirs = make([]DescribeLogDirsResponseDirMetadata, n)
+	for i := 0; i < n; i++ {
+		dir := DescribeLogDirsResponseDirMetadata{}
+		if err := dir.decode(pd, version); err != nil {
+			return err
+		}
+		r.LogDirs[i] = dir
+	}
+
+	return nil
+}
+
+func (r *DescribeLogDirsResponse) key() int16 {
+	return 35
+}
+
+func (r *DescribeLogDirsResponse) version() int16 {
+	return r.Version
+}
+
+func (r *DescribeLogDirsResponse) requiredVersion() KafkaVersion {
+	return V1_0_0_0
+}
+
+type DescribeLogDirsResponseDirMetadata struct {
+	ErrorCode KError
+
+	// The absolute log directory path
+	Path   string
+	Topics []DescribeLogDirsResponseTopic
+}
+
+func (r *DescribeLogDirsResponseDirMetadata) encode(pe packetEncoder) error {
+	pe.putInt16(int16(r.ErrorCode))
+
+	if err := pe.putString(r.Path); err != nil {
+		return err
+	}
+
+	for _, topic := range r.Topics {
+		if err := topic.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *DescribeLogDirsResponseDirMetadata) decode(pd packetDecoder, version int16) error {
+	errCode, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	r.ErrorCode = KError(errCode)
+
+	path, err := pd.getString()
+	if err != nil {
+		return err
+	}
+	r.Path = path
+
+	// Decode array of DescribeLogDirsResponseTopic
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Topics = make([]DescribeLogDirsResponseTopic, n)
+	for i := 0; i < n; i++ {
+		t := DescribeLogDirsResponseTopic{}
+
+		if err := t.decode(pd, version); err != nil {
+			return err
+		}
+
+		r.Topics[i] = t
+	}
+
+	return nil
+}
+
+// DescribeLogDirsResponseTopic contains a topic's partitions descriptions
+type DescribeLogDirsResponseTopic struct {
+	Topic      string
+	Partitions []DescribeLogDirsResponsePartition
+}
+
+func (r *DescribeLogDirsResponseTopic) encode(pe packetEncoder) error {
+	if err := pe.putString(r.Topic); err != nil {
+		return err
+	}
+
+	for _, partition := range r.Partitions {
+		if err := partition.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *DescribeLogDirsResponseTopic) decode(pd packetDecoder, version int16) error {
+	t, err := pd.getString()
+	if err != nil {
+		return err
+	}
+	r.Topic = t
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	r.Partitions = make([]DescribeLogDirsResponsePartition, n)
+	for i := 0; i < n; i++ {
+		p := DescribeLogDirsResponsePartition{}
+		if err := p.decode(pd, version); err != nil {
+			return err
+		}
+		r.Partitions[i] = p
+	}
+
+	return nil
+}
+
+// DescribeLogDirsResponsePartition describes a partition's log directory
+type DescribeLogDirsResponsePartition struct {
+	PartitionID int32
+
+	// The size of the log segments of the partition in bytes.
+	Size int64
+
+	// The lag of the log's LEO w.r.t. partition's HW (if it is the current log for the partition) or
+	// current replica's LEO (if it is the future log for the partition)
+	OffsetLag int64
+
+	// True if this log is created by AlterReplicaLogDirsRequest and will replace the current log of
+	// the replica in the future.
+	IsTemporary bool
+}
+
+func (r *DescribeLogDirsResponsePartition) encode(pe packetEncoder) error {
+	pe.putInt32(r.PartitionID)
+	pe.putInt64(r.Size)
+	pe.putInt64(r.OffsetLag)
+	pe.putBool(r.IsTemporary)
+
+	return nil
+}
+
+func (r *DescribeLogDirsResponsePartition) decode(pd packetDecoder, version int16) error {
+	pID, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	r.PartitionID = pID
+
+	size, err := pd.getInt64()
+	if err != nil {
+		return err
+	}
+	r.Size = size
+
+	lag, err := pd.getInt64()
+	if err != nil {
+		return err
+	}
+	r.OffsetLag = lag
+
+	isTemp, err := pd.getBool()
+	if err != nil {
+		return err
+	}
+	r.IsTemporary = isTemp
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/dev.yml b/vendor/github.com/Shopify/sarama/dev.yml
new file mode 100644
index 0000000..4c030de
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/dev.yml
@@ -0,0 +1,10 @@
+name: sarama
+
+up:
+  - go:
+      version: '1.13.4'
+
+commands:
+  test:
+    run: make test
+    desc: 'run unit tests'
diff --git a/vendor/github.com/Shopify/sarama/encoder_decoder.go b/vendor/github.com/Shopify/sarama/encoder_decoder.go
new file mode 100644
index 0000000..7ce3bc0
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/encoder_decoder.go
@@ -0,0 +1,89 @@
+package sarama
+
+import (
+	"fmt"
+
+	"github.com/rcrowley/go-metrics"
+)
+
+// Encoder is the interface that wraps the basic Encode method.
+// Anything implementing Encoder can be turned into bytes using Kafka's encoding rules.
+type encoder interface {
+	encode(pe packetEncoder) error
+}
+
+// Encode takes an Encoder and turns it into bytes while potentially recording metrics.
+func encode(e encoder, metricRegistry metrics.Registry) ([]byte, error) {
+	if e == nil {
+		return nil, nil
+	}
+
+	var prepEnc prepEncoder
+	var realEnc realEncoder
+
+	err := e.encode(&prepEnc)
+	if err != nil {
+		return nil, err
+	}
+
+	if prepEnc.length < 0 || prepEnc.length > int(MaxRequestSize) {
+		return nil, PacketEncodingError{fmt.Sprintf("invalid request size (%d)", prepEnc.length)}
+	}
+
+	realEnc.raw = make([]byte, prepEnc.length)
+	realEnc.registry = metricRegistry
+	err = e.encode(&realEnc)
+	if err != nil {
+		return nil, err
+	}
+
+	return realEnc.raw, nil
+}
+
+// Decoder is the interface that wraps the basic Decode method.
+// Anything implementing Decoder can be extracted from bytes using Kafka's encoding rules.
+type decoder interface {
+	decode(pd packetDecoder) error
+}
+
+type versionedDecoder interface {
+	decode(pd packetDecoder, version int16) error
+}
+
+// Decode takes bytes and a Decoder and fills the fields of the decoder from the bytes,
+// interpreted using Kafka's encoding rules.
+func decode(buf []byte, in decoder) error {
+	if buf == nil {
+		return nil
+	}
+
+	helper := realDecoder{raw: buf}
+	err := in.decode(&helper)
+	if err != nil {
+		return err
+	}
+
+	if helper.off != len(buf) {
+		return PacketDecodingError{"invalid length"}
+	}
+
+	return nil
+}
+
+func versionedDecode(buf []byte, in versionedDecoder, version int16) error {
+	if buf == nil {
+		return nil
+	}
+
+	helper := realDecoder{raw: buf}
+	err := in.decode(&helper, version)
+	if err != nil {
+		return err
+	}
+
+	if helper.off != len(buf) {
+		return PacketDecodingError{"invalid length"}
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/end_txn_request.go b/vendor/github.com/Shopify/sarama/end_txn_request.go
new file mode 100644
index 0000000..2cd9b50
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/end_txn_request.go
@@ -0,0 +1,50 @@
+package sarama
+
+type EndTxnRequest struct {
+	TransactionalID   string
+	ProducerID        int64
+	ProducerEpoch     int16
+	TransactionResult bool
+}
+
+func (a *EndTxnRequest) encode(pe packetEncoder) error {
+	if err := pe.putString(a.TransactionalID); err != nil {
+		return err
+	}
+
+	pe.putInt64(a.ProducerID)
+
+	pe.putInt16(a.ProducerEpoch)
+
+	pe.putBool(a.TransactionResult)
+
+	return nil
+}
+
+func (a *EndTxnRequest) decode(pd packetDecoder, version int16) (err error) {
+	if a.TransactionalID, err = pd.getString(); err != nil {
+		return err
+	}
+	if a.ProducerID, err = pd.getInt64(); err != nil {
+		return err
+	}
+	if a.ProducerEpoch, err = pd.getInt16(); err != nil {
+		return err
+	}
+	if a.TransactionResult, err = pd.getBool(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (a *EndTxnRequest) key() int16 {
+	return 26
+}
+
+func (a *EndTxnRequest) version() int16 {
+	return 0
+}
+
+func (a *EndTxnRequest) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/end_txn_response.go b/vendor/github.com/Shopify/sarama/end_txn_response.go
new file mode 100644
index 0000000..33b27e3
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/end_txn_response.go
@@ -0,0 +1,44 @@
+package sarama
+
+import (
+	"time"
+)
+
+type EndTxnResponse struct {
+	ThrottleTime time.Duration
+	Err          KError
+}
+
+func (e *EndTxnResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(e.ThrottleTime / time.Millisecond))
+	pe.putInt16(int16(e.Err))
+	return nil
+}
+
+func (e *EndTxnResponse) decode(pd packetDecoder, version int16) (err error) {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	e.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	e.Err = KError(kerr)
+
+	return nil
+}
+
+func (e *EndTxnResponse) key() int16 {
+	return 25
+}
+
+func (e *EndTxnResponse) version() int16 {
+	return 0
+}
+
+func (e *EndTxnResponse) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/errors.go b/vendor/github.com/Shopify/sarama/errors.go
new file mode 100644
index 0000000..97be3c0
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/errors.go
@@ -0,0 +1,369 @@
+package sarama
+
+import (
+	"errors"
+	"fmt"
+)
+
+// ErrOutOfBrokers is the error returned when the client has run out of brokers to talk to because all of them errored
+// or otherwise failed to respond.
+var ErrOutOfBrokers = errors.New("kafka: client has run out of available brokers to talk to (Is your cluster reachable?)")
+
+// ErrClosedClient is the error returned when a method is called on a client that has been closed.
+var ErrClosedClient = errors.New("kafka: tried to use a client that was closed")
+
+// ErrIncompleteResponse is the error returned when the server returns a syntactically valid response, but it does
+// not contain the expected information.
+var ErrIncompleteResponse = errors.New("kafka: response did not contain all the expected topic/partition blocks")
+
+// ErrInvalidPartition is the error returned when a partitioner returns an invalid partition index
+// (meaning one outside of the range [0...numPartitions-1]).
+var ErrInvalidPartition = errors.New("kafka: partitioner returned an invalid partition index")
+
+// ErrAlreadyConnected is the error returned when calling Open() on a Broker that is already connected or connecting.
+var ErrAlreadyConnected = errors.New("kafka: broker connection already initiated")
+
+// ErrNotConnected is the error returned when trying to send or call Close() on a Broker that is not connected.
+var ErrNotConnected = errors.New("kafka: broker not connected")
+
+// ErrInsufficientData is returned when decoding and the packet is truncated. This can be expected
+// when requesting messages, since as an optimization the server is allowed to return a partial message at the end
+// of the message set.
+var ErrInsufficientData = errors.New("kafka: insufficient data to decode packet, more bytes expected")
+
+// ErrShuttingDown is returned when a producer receives a message during shutdown.
+var ErrShuttingDown = errors.New("kafka: message received by producer in process of shutting down")
+
+// ErrMessageTooLarge is returned when the next message to consume is larger than the configured Consumer.Fetch.Max
+var ErrMessageTooLarge = errors.New("kafka: message is larger than Consumer.Fetch.Max")
+
+// ErrConsumerOffsetNotAdvanced is returned when a partition consumer didn't advance its offset after parsing
+// a RecordBatch.
+var ErrConsumerOffsetNotAdvanced = errors.New("kafka: consumer offset was not advanced after a RecordBatch")
+
+// ErrControllerNotAvailable is returned when server didn't give correct controller id. May be kafka server's version
+// is lower than 0.10.0.0.
+var ErrControllerNotAvailable = errors.New("kafka: controller is not available")
+
+// ErrNoTopicsToUpdateMetadata is returned when Meta.Full is set to false but no specific topics were found to update
+// the metadata.
+var ErrNoTopicsToUpdateMetadata = errors.New("kafka: no specific topics to update metadata")
+
+// PacketEncodingError is returned from a failure while encoding a Kafka packet. This can happen, for example,
+// if you try to encode a string over 2^15 characters in length, since Kafka's encoding rules do not permit that.
+type PacketEncodingError struct {
+	Info string
+}
+
+func (err PacketEncodingError) Error() string {
+	return fmt.Sprintf("kafka: error encoding packet: %s", err.Info)
+}
+
+// PacketDecodingError is returned when there was an error (other than truncated data) decoding the Kafka broker's response.
+// This can be a bad CRC or length field, or any other invalid value.
+type PacketDecodingError struct {
+	Info string
+}
+
+func (err PacketDecodingError) Error() string {
+	return fmt.Sprintf("kafka: error decoding packet: %s", err.Info)
+}
+
+// ConfigurationError is the type of error returned from a constructor (e.g. NewClient, or NewConsumer)
+// when the specified configuration is invalid.
+type ConfigurationError string
+
+func (err ConfigurationError) Error() string {
+	return "kafka: invalid configuration (" + string(err) + ")"
+}
+
+// KError is the type of error that can be returned directly by the Kafka broker.
+// See https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol#AGuideToTheKafkaProtocol-ErrorCodes
+type KError int16
+
+// MultiError is used to contain multi error.
+type MultiError struct {
+	Errors *[]error
+}
+
+func (mErr MultiError) Error() string {
+	var errString = ""
+	for _, err := range *mErr.Errors {
+		errString += err.Error() + ","
+	}
+	return errString
+}
+
+// ErrDeleteRecords is the type of error returned when fail to delete the required records
+type ErrDeleteRecords struct {
+	MultiError
+}
+
+func (err ErrDeleteRecords) Error() string {
+	return "kafka server: failed to delete records " + err.MultiError.Error()
+}
+
+// Numeric error codes returned by the Kafka server.
+const (
+	ErrNoError                            KError = 0
+	ErrUnknown                            KError = -1
+	ErrOffsetOutOfRange                   KError = 1
+	ErrInvalidMessage                     KError = 2
+	ErrUnknownTopicOrPartition            KError = 3
+	ErrInvalidMessageSize                 KError = 4
+	ErrLeaderNotAvailable                 KError = 5
+	ErrNotLeaderForPartition              KError = 6
+	ErrRequestTimedOut                    KError = 7
+	ErrBrokerNotAvailable                 KError = 8
+	ErrReplicaNotAvailable                KError = 9
+	ErrMessageSizeTooLarge                KError = 10
+	ErrStaleControllerEpochCode           KError = 11
+	ErrOffsetMetadataTooLarge             KError = 12
+	ErrNetworkException                   KError = 13
+	ErrOffsetsLoadInProgress              KError = 14
+	ErrConsumerCoordinatorNotAvailable    KError = 15
+	ErrNotCoordinatorForConsumer          KError = 16
+	ErrInvalidTopic                       KError = 17
+	ErrMessageSetSizeTooLarge             KError = 18
+	ErrNotEnoughReplicas                  KError = 19
+	ErrNotEnoughReplicasAfterAppend       KError = 20
+	ErrInvalidRequiredAcks                KError = 21
+	ErrIllegalGeneration                  KError = 22
+	ErrInconsistentGroupProtocol          KError = 23
+	ErrInvalidGroupId                     KError = 24
+	ErrUnknownMemberId                    KError = 25
+	ErrInvalidSessionTimeout              KError = 26
+	ErrRebalanceInProgress                KError = 27
+	ErrInvalidCommitOffsetSize            KError = 28
+	ErrTopicAuthorizationFailed           KError = 29
+	ErrGroupAuthorizationFailed           KError = 30
+	ErrClusterAuthorizationFailed         KError = 31
+	ErrInvalidTimestamp                   KError = 32
+	ErrUnsupportedSASLMechanism           KError = 33
+	ErrIllegalSASLState                   KError = 34
+	ErrUnsupportedVersion                 KError = 35
+	ErrTopicAlreadyExists                 KError = 36
+	ErrInvalidPartitions                  KError = 37
+	ErrInvalidReplicationFactor           KError = 38
+	ErrInvalidReplicaAssignment           KError = 39
+	ErrInvalidConfig                      KError = 40
+	ErrNotController                      KError = 41
+	ErrInvalidRequest                     KError = 42
+	ErrUnsupportedForMessageFormat        KError = 43
+	ErrPolicyViolation                    KError = 44
+	ErrOutOfOrderSequenceNumber           KError = 45
+	ErrDuplicateSequenceNumber            KError = 46
+	ErrInvalidProducerEpoch               KError = 47
+	ErrInvalidTxnState                    KError = 48
+	ErrInvalidProducerIDMapping           KError = 49
+	ErrInvalidTransactionTimeout          KError = 50
+	ErrConcurrentTransactions             KError = 51
+	ErrTransactionCoordinatorFenced       KError = 52
+	ErrTransactionalIDAuthorizationFailed KError = 53
+	ErrSecurityDisabled                   KError = 54
+	ErrOperationNotAttempted              KError = 55
+	ErrKafkaStorageError                  KError = 56
+	ErrLogDirNotFound                     KError = 57
+	ErrSASLAuthenticationFailed           KError = 58
+	ErrUnknownProducerID                  KError = 59
+	ErrReassignmentInProgress             KError = 60
+	ErrDelegationTokenAuthDisabled        KError = 61
+	ErrDelegationTokenNotFound            KError = 62
+	ErrDelegationTokenOwnerMismatch       KError = 63
+	ErrDelegationTokenRequestNotAllowed   KError = 64
+	ErrDelegationTokenAuthorizationFailed KError = 65
+	ErrDelegationTokenExpired             KError = 66
+	ErrInvalidPrincipalType               KError = 67
+	ErrNonEmptyGroup                      KError = 68
+	ErrGroupIDNotFound                    KError = 69
+	ErrFetchSessionIDNotFound             KError = 70
+	ErrInvalidFetchSessionEpoch           KError = 71
+	ErrListenerNotFound                   KError = 72
+	ErrTopicDeletionDisabled              KError = 73
+	ErrFencedLeaderEpoch                  KError = 74
+	ErrUnknownLeaderEpoch                 KError = 75
+	ErrUnsupportedCompressionType         KError = 76
+	ErrStaleBrokerEpoch                   KError = 77
+	ErrOffsetNotAvailable                 KError = 78
+	ErrMemberIdRequired                   KError = 79
+	ErrPreferredLeaderNotAvailable        KError = 80
+	ErrGroupMaxSizeReached                KError = 81
+	ErrFencedInstancedId                  KError = 82
+)
+
+func (err KError) Error() string {
+	// Error messages stolen/adapted from
+	// https://kafka.apache.org/protocol#protocol_error_codes
+	switch err {
+	case ErrNoError:
+		return "kafka server: Not an error, why are you printing me?"
+	case ErrUnknown:
+		return "kafka server: Unexpected (unknown?) server error."
+	case ErrOffsetOutOfRange:
+		return "kafka server: The requested offset is outside the range of offsets maintained by the server for the given topic/partition."
+	case ErrInvalidMessage:
+		return "kafka server: Message contents does not match its CRC."
+	case ErrUnknownTopicOrPartition:
+		return "kafka server: Request was for a topic or partition that does not exist on this broker."
+	case ErrInvalidMessageSize:
+		return "kafka server: The message has a negative size."
+	case ErrLeaderNotAvailable:
+		return "kafka server: In the middle of a leadership election, there is currently no leader for this partition and hence it is unavailable for writes."
+	case ErrNotLeaderForPartition:
+		return "kafka server: Tried to send a message to a replica that is not the leader for some partition. Your metadata is out of date."
+	case ErrRequestTimedOut:
+		return "kafka server: Request exceeded the user-specified time limit in the request."
+	case ErrBrokerNotAvailable:
+		return "kafka server: Broker not available. Not a client facing error, we should never receive this!!!"
+	case ErrReplicaNotAvailable:
+		return "kafka server: Replica information not available, one or more brokers are down."
+	case ErrMessageSizeTooLarge:
+		return "kafka server: Message was too large, server rejected it to avoid allocation error."
+	case ErrStaleControllerEpochCode:
+		return "kafka server: StaleControllerEpochCode (internal error code for broker-to-broker communication)."
+	case ErrOffsetMetadataTooLarge:
+		return "kafka server: Specified a string larger than the configured maximum for offset metadata."
+	case ErrNetworkException:
+		return "kafka server: The server disconnected before a response was received."
+	case ErrOffsetsLoadInProgress:
+		return "kafka server: The broker is still loading offsets after a leader change for that offset's topic partition."
+	case ErrConsumerCoordinatorNotAvailable:
+		return "kafka server: Offset's topic has not yet been created."
+	case ErrNotCoordinatorForConsumer:
+		return "kafka server: Request was for a consumer group that is not coordinated by this broker."
+	case ErrInvalidTopic:
+		return "kafka server: The request attempted to perform an operation on an invalid topic."
+	case ErrMessageSetSizeTooLarge:
+		return "kafka server: The request included message batch larger than the configured segment size on the server."
+	case ErrNotEnoughReplicas:
+		return "kafka server: Messages are rejected since there are fewer in-sync replicas than required."
+	case ErrNotEnoughReplicasAfterAppend:
+		return "kafka server: Messages are written to the log, but to fewer in-sync replicas than required."
+	case ErrInvalidRequiredAcks:
+		return "kafka server: The number of required acks is invalid (should be either -1, 0, or 1)."
+	case ErrIllegalGeneration:
+		return "kafka server: The provided generation id is not the current generation."
+	case ErrInconsistentGroupProtocol:
+		return "kafka server: The provider group protocol type is incompatible with the other members."
+	case ErrInvalidGroupId:
+		return "kafka server: The provided group id was empty."
+	case ErrUnknownMemberId:
+		return "kafka server: The provided member is not known in the current generation."
+	case ErrInvalidSessionTimeout:
+		return "kafka server: The provided session timeout is outside the allowed range."
+	case ErrRebalanceInProgress:
+		return "kafka server: A rebalance for the group is in progress. Please re-join the group."
+	case ErrInvalidCommitOffsetSize:
+		return "kafka server: The provided commit metadata was too large."
+	case ErrTopicAuthorizationFailed:
+		return "kafka server: The client is not authorized to access this topic."
+	case ErrGroupAuthorizationFailed:
+		return "kafka server: The client is not authorized to access this group."
+	case ErrClusterAuthorizationFailed:
+		return "kafka server: The client is not authorized to send this request type."
+	case ErrInvalidTimestamp:
+		return "kafka server: The timestamp of the message is out of acceptable range."
+	case ErrUnsupportedSASLMechanism:
+		return "kafka server: The broker does not support the requested SASL mechanism."
+	case ErrIllegalSASLState:
+		return "kafka server: Request is not valid given the current SASL state."
+	case ErrUnsupportedVersion:
+		return "kafka server: The version of API is not supported."
+	case ErrTopicAlreadyExists:
+		return "kafka server: Topic with this name already exists."
+	case ErrInvalidPartitions:
+		return "kafka server: Number of partitions is invalid."
+	case ErrInvalidReplicationFactor:
+		return "kafka server: Replication-factor is invalid."
+	case ErrInvalidReplicaAssignment:
+		return "kafka server: Replica assignment is invalid."
+	case ErrInvalidConfig:
+		return "kafka server: Configuration is invalid."
+	case ErrNotController:
+		return "kafka server: This is not the correct controller for this cluster."
+	case ErrInvalidRequest:
+		return "kafka server: This most likely occurs because of a request being malformed by the client library or the message was sent to an incompatible broker. See the broker logs for more details."
+	case ErrUnsupportedForMessageFormat:
+		return "kafka server: The requested operation is not supported by the message format version."
+	case ErrPolicyViolation:
+		return "kafka server: Request parameters do not satisfy the configured policy."
+	case ErrOutOfOrderSequenceNumber:
+		return "kafka server: The broker received an out of order sequence number."
+	case ErrDuplicateSequenceNumber:
+		return "kafka server: The broker received a duplicate sequence number."
+	case ErrInvalidProducerEpoch:
+		return "kafka server: Producer attempted an operation with an old epoch."
+	case ErrInvalidTxnState:
+		return "kafka server: The producer attempted a transactional operation in an invalid state."
+	case ErrInvalidProducerIDMapping:
+		return "kafka server: The producer attempted to use a producer id which is not currently assigned to its transactional id."
+	case ErrInvalidTransactionTimeout:
+		return "kafka server: The transaction timeout is larger than the maximum value allowed by the broker (as configured by max.transaction.timeout.ms)."
+	case ErrConcurrentTransactions:
+		return "kafka server: The producer attempted to update a transaction while another concurrent operation on the same transaction was ongoing."
+	case ErrTransactionCoordinatorFenced:
+		return "kafka server: The transaction coordinator sending a WriteTxnMarker is no longer the current coordinator for a given producer."
+	case ErrTransactionalIDAuthorizationFailed:
+		return "kafka server: Transactional ID authorization failed."
+	case ErrSecurityDisabled:
+		return "kafka server: Security features are disabled."
+	case ErrOperationNotAttempted:
+		return "kafka server: The broker did not attempt to execute this operation."
+	case ErrKafkaStorageError:
+		return "kafka server: Disk error when trying to access log file on the disk."
+	case ErrLogDirNotFound:
+		return "kafka server: The specified log directory is not found in the broker config."
+	case ErrSASLAuthenticationFailed:
+		return "kafka server: SASL Authentication failed."
+	case ErrUnknownProducerID:
+		return "kafka server: The broker could not locate the producer metadata associated with the Producer ID."
+	case ErrReassignmentInProgress:
+		return "kafka server: A partition reassignment is in progress."
+	case ErrDelegationTokenAuthDisabled:
+		return "kafka server: Delegation Token feature is not enabled."
+	case ErrDelegationTokenNotFound:
+		return "kafka server: Delegation Token is not found on server."
+	case ErrDelegationTokenOwnerMismatch:
+		return "kafka server: Specified Principal is not valid Owner/Renewer."
+	case ErrDelegationTokenRequestNotAllowed:
+		return "kafka server: Delegation Token requests are not allowed on PLAINTEXT/1-way SSL channels and on delegation token authenticated channels."
+	case ErrDelegationTokenAuthorizationFailed:
+		return "kafka server: Delegation Token authorization failed."
+	case ErrDelegationTokenExpired:
+		return "kafka server: Delegation Token is expired."
+	case ErrInvalidPrincipalType:
+		return "kafka server: Supplied principalType is not supported."
+	case ErrNonEmptyGroup:
+		return "kafka server: The group is not empty."
+	case ErrGroupIDNotFound:
+		return "kafka server: The group id does not exist."
+	case ErrFetchSessionIDNotFound:
+		return "kafka server: The fetch session ID was not found."
+	case ErrInvalidFetchSessionEpoch:
+		return "kafka server: The fetch session epoch is invalid."
+	case ErrListenerNotFound:
+		return "kafka server: There is no listener on the leader broker that matches the listener on which metadata request was processed."
+	case ErrTopicDeletionDisabled:
+		return "kafka server: Topic deletion is disabled."
+	case ErrFencedLeaderEpoch:
+		return "kafka server: The leader epoch in the request is older than the epoch on the broker."
+	case ErrUnknownLeaderEpoch:
+		return "kafka server: The leader epoch in the request is newer than the epoch on the broker."
+	case ErrUnsupportedCompressionType:
+		return "kafka server: The requesting client does not support the compression type of given partition."
+	case ErrStaleBrokerEpoch:
+		return "kafka server: Broker epoch has changed"
+	case ErrOffsetNotAvailable:
+		return "kafka server: The leader high watermark has not caught up from a recent leader election so the offsets cannot be guaranteed to be monotonically increasing"
+	case ErrMemberIdRequired:
+		return "kafka server: The group member needs to have a valid member id before actually entering a consumer group"
+	case ErrPreferredLeaderNotAvailable:
+		return "kafka server: The preferred leader was not available"
+	case ErrGroupMaxSizeReached:
+		return "kafka server: Consumer group The consumer group has reached its max size. already has the configured maximum number of members."
+	case ErrFencedInstancedId:
+		return "kafka server: The broker rejected this static consumer since another consumer with the same group.instance.id has registered with a different member.id."
+	}
+
+	return fmt.Sprintf("Unknown error, how did this happen? Error code = %d", err)
+}
diff --git a/vendor/github.com/Shopify/sarama/fetch_request.go b/vendor/github.com/Shopify/sarama/fetch_request.go
new file mode 100644
index 0000000..4db9ddd
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/fetch_request.go
@@ -0,0 +1,170 @@
+package sarama
+
+type fetchRequestBlock struct {
+	fetchOffset int64
+	maxBytes    int32
+}
+
+func (b *fetchRequestBlock) encode(pe packetEncoder) error {
+	pe.putInt64(b.fetchOffset)
+	pe.putInt32(b.maxBytes)
+	return nil
+}
+
+func (b *fetchRequestBlock) decode(pd packetDecoder) (err error) {
+	if b.fetchOffset, err = pd.getInt64(); err != nil {
+		return err
+	}
+	if b.maxBytes, err = pd.getInt32(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// FetchRequest (API key 1) will fetch Kafka messages. Version 3 introduced the MaxBytes field. See
+// https://issues.apache.org/jira/browse/KAFKA-2063 for a discussion of the issues leading up to that.  The KIP is at
+// https://cwiki.apache.org/confluence/display/KAFKA/KIP-74%3A+Add+Fetch+Response+Size+Limit+in+Bytes
+type FetchRequest struct {
+	MaxWaitTime int32
+	MinBytes    int32
+	MaxBytes    int32
+	Version     int16
+	Isolation   IsolationLevel
+	blocks      map[string]map[int32]*fetchRequestBlock
+}
+
+type IsolationLevel int8
+
+const (
+	ReadUncommitted IsolationLevel = iota
+	ReadCommitted
+)
+
+func (r *FetchRequest) encode(pe packetEncoder) (err error) {
+	pe.putInt32(-1) // replica ID is always -1 for clients
+	pe.putInt32(r.MaxWaitTime)
+	pe.putInt32(r.MinBytes)
+	if r.Version >= 3 {
+		pe.putInt32(r.MaxBytes)
+	}
+	if r.Version >= 4 {
+		pe.putInt8(int8(r.Isolation))
+	}
+	err = pe.putArrayLength(len(r.blocks))
+	if err != nil {
+		return err
+	}
+	for topic, blocks := range r.blocks {
+		err = pe.putString(topic)
+		if err != nil {
+			return err
+		}
+		err = pe.putArrayLength(len(blocks))
+		if err != nil {
+			return err
+		}
+		for partition, block := range blocks {
+			pe.putInt32(partition)
+			err = block.encode(pe)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (r *FetchRequest) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+	if _, err = pd.getInt32(); err != nil {
+		return err
+	}
+	if r.MaxWaitTime, err = pd.getInt32(); err != nil {
+		return err
+	}
+	if r.MinBytes, err = pd.getInt32(); err != nil {
+		return err
+	}
+	if r.Version >= 3 {
+		if r.MaxBytes, err = pd.getInt32(); err != nil {
+			return err
+		}
+	}
+	if r.Version >= 4 {
+		isolation, err := pd.getInt8()
+		if err != nil {
+			return err
+		}
+		r.Isolation = IsolationLevel(isolation)
+	}
+	topicCount, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if topicCount == 0 {
+		return nil
+	}
+	r.blocks = make(map[string]map[int32]*fetchRequestBlock)
+	for i := 0; i < topicCount; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		partitionCount, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+		r.blocks[topic] = make(map[int32]*fetchRequestBlock)
+		for j := 0; j < partitionCount; j++ {
+			partition, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+			fetchBlock := &fetchRequestBlock{}
+			if err = fetchBlock.decode(pd); err != nil {
+				return err
+			}
+			r.blocks[topic][partition] = fetchBlock
+		}
+	}
+	return nil
+}
+
+func (r *FetchRequest) key() int16 {
+	return 1
+}
+
+func (r *FetchRequest) version() int16 {
+	return r.Version
+}
+
+func (r *FetchRequest) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_9_0_0
+	case 2:
+		return V0_10_0_0
+	case 3:
+		return V0_10_1_0
+	case 4:
+		return V0_11_0_0
+	default:
+		return MinVersion
+	}
+}
+
+func (r *FetchRequest) AddBlock(topic string, partitionID int32, fetchOffset int64, maxBytes int32) {
+	if r.blocks == nil {
+		r.blocks = make(map[string]map[int32]*fetchRequestBlock)
+	}
+
+	if r.blocks[topic] == nil {
+		r.blocks[topic] = make(map[int32]*fetchRequestBlock)
+	}
+
+	tmp := new(fetchRequestBlock)
+	tmp.maxBytes = maxBytes
+	tmp.fetchOffset = fetchOffset
+
+	r.blocks[topic][partitionID] = tmp
+}
diff --git a/vendor/github.com/Shopify/sarama/fetch_response.go b/vendor/github.com/Shopify/sarama/fetch_response.go
new file mode 100644
index 0000000..3afc187
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/fetch_response.go
@@ -0,0 +1,489 @@
+package sarama
+
+import (
+	"sort"
+	"time"
+)
+
+type AbortedTransaction struct {
+	ProducerID  int64
+	FirstOffset int64
+}
+
+func (t *AbortedTransaction) decode(pd packetDecoder) (err error) {
+	if t.ProducerID, err = pd.getInt64(); err != nil {
+		return err
+	}
+
+	if t.FirstOffset, err = pd.getInt64(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (t *AbortedTransaction) encode(pe packetEncoder) (err error) {
+	pe.putInt64(t.ProducerID)
+	pe.putInt64(t.FirstOffset)
+
+	return nil
+}
+
+type FetchResponseBlock struct {
+	Err                 KError
+	HighWaterMarkOffset int64
+	LastStableOffset    int64
+	AbortedTransactions []*AbortedTransaction
+	Records             *Records // deprecated: use FetchResponseBlock.RecordsSet
+	RecordsSet          []*Records
+	Partial             bool
+}
+
+func (b *FetchResponseBlock) decode(pd packetDecoder, version int16) (err error) {
+	tmp, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	b.Err = KError(tmp)
+
+	b.HighWaterMarkOffset, err = pd.getInt64()
+	if err != nil {
+		return err
+	}
+
+	if version >= 4 {
+		b.LastStableOffset, err = pd.getInt64()
+		if err != nil {
+			return err
+		}
+
+		numTransact, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+
+		if numTransact >= 0 {
+			b.AbortedTransactions = make([]*AbortedTransaction, numTransact)
+		}
+
+		for i := 0; i < numTransact; i++ {
+			transact := new(AbortedTransaction)
+			if err = transact.decode(pd); err != nil {
+				return err
+			}
+			b.AbortedTransactions[i] = transact
+		}
+	}
+
+	recordsSize, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+
+	recordsDecoder, err := pd.getSubset(int(recordsSize))
+	if err != nil {
+		return err
+	}
+
+	b.RecordsSet = []*Records{}
+
+	for recordsDecoder.remaining() > 0 {
+		records := &Records{}
+		if err := records.decode(recordsDecoder); err != nil {
+			// If we have at least one decoded records, this is not an error
+			if err == ErrInsufficientData {
+				if len(b.RecordsSet) == 0 {
+					b.Partial = true
+				}
+				break
+			}
+			return err
+		}
+
+		partial, err := records.isPartial()
+		if err != nil {
+			return err
+		}
+
+		n, err := records.numRecords()
+		if err != nil {
+			return err
+		}
+
+		if n > 0 || (partial && len(b.RecordsSet) == 0) {
+			b.RecordsSet = append(b.RecordsSet, records)
+
+			if b.Records == nil {
+				b.Records = records
+			}
+		}
+
+		overflow, err := records.isOverflow()
+		if err != nil {
+			return err
+		}
+
+		if partial || overflow {
+			break
+		}
+	}
+
+	return nil
+}
+
+func (b *FetchResponseBlock) numRecords() (int, error) {
+	sum := 0
+
+	for _, records := range b.RecordsSet {
+		count, err := records.numRecords()
+		if err != nil {
+			return 0, err
+		}
+
+		sum += count
+	}
+
+	return sum, nil
+}
+
+func (b *FetchResponseBlock) isPartial() (bool, error) {
+	if b.Partial {
+		return true, nil
+	}
+
+	if len(b.RecordsSet) == 1 {
+		return b.RecordsSet[0].isPartial()
+	}
+
+	return false, nil
+}
+
+func (b *FetchResponseBlock) encode(pe packetEncoder, version int16) (err error) {
+	pe.putInt16(int16(b.Err))
+
+	pe.putInt64(b.HighWaterMarkOffset)
+
+	if version >= 4 {
+		pe.putInt64(b.LastStableOffset)
+
+		if err = pe.putArrayLength(len(b.AbortedTransactions)); err != nil {
+			return err
+		}
+		for _, transact := range b.AbortedTransactions {
+			if err = transact.encode(pe); err != nil {
+				return err
+			}
+		}
+	}
+
+	pe.push(&lengthField{})
+	for _, records := range b.RecordsSet {
+		err = records.encode(pe)
+		if err != nil {
+			return err
+		}
+	}
+	return pe.pop()
+}
+
+func (b *FetchResponseBlock) getAbortedTransactions() []*AbortedTransaction {
+	// I can't find any doc that guarantee the field `fetchResponse.AbortedTransactions` is ordered
+	// plus Java implementation use a PriorityQueue based on `FirstOffset`. I guess we have to order it ourself
+	at := b.AbortedTransactions
+	sort.Slice(
+		at,
+		func(i, j int) bool { return at[i].FirstOffset < at[j].FirstOffset },
+	)
+	return at
+}
+
+type FetchResponse struct {
+	Blocks        map[string]map[int32]*FetchResponseBlock
+	ThrottleTime  time.Duration
+	Version       int16 // v1 requires 0.9+, v2 requires 0.10+
+	LogAppendTime bool
+	Timestamp     time.Time
+}
+
+func (r *FetchResponse) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+
+	if r.Version >= 1 {
+		throttle, err := pd.getInt32()
+		if err != nil {
+			return err
+		}
+		r.ThrottleTime = time.Duration(throttle) * time.Millisecond
+	}
+
+	numTopics, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Blocks = make(map[string]map[int32]*FetchResponseBlock, numTopics)
+	for i := 0; i < numTopics; i++ {
+		name, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		numBlocks, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+
+		r.Blocks[name] = make(map[int32]*FetchResponseBlock, numBlocks)
+
+		for j := 0; j < numBlocks; j++ {
+			id, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+
+			block := new(FetchResponseBlock)
+			err = block.decode(pd, version)
+			if err != nil {
+				return err
+			}
+			r.Blocks[name][id] = block
+		}
+	}
+
+	return nil
+}
+
+func (r *FetchResponse) encode(pe packetEncoder) (err error) {
+	if r.Version >= 1 {
+		pe.putInt32(int32(r.ThrottleTime / time.Millisecond))
+	}
+
+	err = pe.putArrayLength(len(r.Blocks))
+	if err != nil {
+		return err
+	}
+
+	for topic, partitions := range r.Blocks {
+		err = pe.putString(topic)
+		if err != nil {
+			return err
+		}
+
+		err = pe.putArrayLength(len(partitions))
+		if err != nil {
+			return err
+		}
+
+		for id, block := range partitions {
+			pe.putInt32(id)
+			err = block.encode(pe, r.Version)
+			if err != nil {
+				return err
+			}
+		}
+
+	}
+	return nil
+}
+
+func (r *FetchResponse) key() int16 {
+	return 1
+}
+
+func (r *FetchResponse) version() int16 {
+	return r.Version
+}
+
+func (r *FetchResponse) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_9_0_0
+	case 2:
+		return V0_10_0_0
+	case 3:
+		return V0_10_1_0
+	case 4:
+		return V0_11_0_0
+	default:
+		return MinVersion
+	}
+}
+
+func (r *FetchResponse) GetBlock(topic string, partition int32) *FetchResponseBlock {
+	if r.Blocks == nil {
+		return nil
+	}
+
+	if r.Blocks[topic] == nil {
+		return nil
+	}
+
+	return r.Blocks[topic][partition]
+}
+
+func (r *FetchResponse) AddError(topic string, partition int32, err KError) {
+	if r.Blocks == nil {
+		r.Blocks = make(map[string]map[int32]*FetchResponseBlock)
+	}
+	partitions, ok := r.Blocks[topic]
+	if !ok {
+		partitions = make(map[int32]*FetchResponseBlock)
+		r.Blocks[topic] = partitions
+	}
+	frb, ok := partitions[partition]
+	if !ok {
+		frb = new(FetchResponseBlock)
+		partitions[partition] = frb
+	}
+	frb.Err = err
+}
+
+func (r *FetchResponse) getOrCreateBlock(topic string, partition int32) *FetchResponseBlock {
+	if r.Blocks == nil {
+		r.Blocks = make(map[string]map[int32]*FetchResponseBlock)
+	}
+	partitions, ok := r.Blocks[topic]
+	if !ok {
+		partitions = make(map[int32]*FetchResponseBlock)
+		r.Blocks[topic] = partitions
+	}
+	frb, ok := partitions[partition]
+	if !ok {
+		frb = new(FetchResponseBlock)
+		partitions[partition] = frb
+	}
+
+	return frb
+}
+
+func encodeKV(key, value Encoder) ([]byte, []byte) {
+	var kb []byte
+	var vb []byte
+	if key != nil {
+		kb, _ = key.Encode()
+	}
+	if value != nil {
+		vb, _ = value.Encode()
+	}
+
+	return kb, vb
+}
+
+func (r *FetchResponse) AddMessageWithTimestamp(topic string, partition int32, key, value Encoder, offset int64, timestamp time.Time, version int8) {
+	frb := r.getOrCreateBlock(topic, partition)
+	kb, vb := encodeKV(key, value)
+	if r.LogAppendTime {
+		timestamp = r.Timestamp
+	}
+	msg := &Message{Key: kb, Value: vb, LogAppendTime: r.LogAppendTime, Timestamp: timestamp, Version: version}
+	msgBlock := &MessageBlock{Msg: msg, Offset: offset}
+	if len(frb.RecordsSet) == 0 {
+		records := newLegacyRecords(&MessageSet{})
+		frb.RecordsSet = []*Records{&records}
+	}
+	set := frb.RecordsSet[0].MsgSet
+	set.Messages = append(set.Messages, msgBlock)
+}
+
+func (r *FetchResponse) AddRecordWithTimestamp(topic string, partition int32, key, value Encoder, offset int64, timestamp time.Time) {
+	frb := r.getOrCreateBlock(topic, partition)
+	kb, vb := encodeKV(key, value)
+	if len(frb.RecordsSet) == 0 {
+		records := newDefaultRecords(&RecordBatch{Version: 2, LogAppendTime: r.LogAppendTime, FirstTimestamp: timestamp, MaxTimestamp: r.Timestamp})
+		frb.RecordsSet = []*Records{&records}
+	}
+	batch := frb.RecordsSet[0].RecordBatch
+	rec := &Record{Key: kb, Value: vb, OffsetDelta: offset, TimestampDelta: timestamp.Sub(batch.FirstTimestamp)}
+	batch.addRecord(rec)
+}
+
+// AddRecordBatchWithTimestamp is similar to AddRecordWithTimestamp
+// But instead of appending 1 record to a batch, it append a new batch containing 1 record to the fetchResponse
+// Since transaction are handled on batch level (the whole batch is either committed or aborted), use this to test transactions
+func (r *FetchResponse) AddRecordBatchWithTimestamp(topic string, partition int32, key, value Encoder, offset int64, producerID int64, isTransactional bool, timestamp time.Time) {
+	frb := r.getOrCreateBlock(topic, partition)
+	kb, vb := encodeKV(key, value)
+
+	records := newDefaultRecords(&RecordBatch{Version: 2, LogAppendTime: r.LogAppendTime, FirstTimestamp: timestamp, MaxTimestamp: r.Timestamp})
+	batch := &RecordBatch{
+		Version:         2,
+		LogAppendTime:   r.LogAppendTime,
+		FirstTimestamp:  timestamp,
+		MaxTimestamp:    r.Timestamp,
+		FirstOffset:     offset,
+		LastOffsetDelta: 0,
+		ProducerID:      producerID,
+		IsTransactional: isTransactional,
+	}
+	rec := &Record{Key: kb, Value: vb, OffsetDelta: 0, TimestampDelta: timestamp.Sub(batch.FirstTimestamp)}
+	batch.addRecord(rec)
+	records.RecordBatch = batch
+
+	frb.RecordsSet = append(frb.RecordsSet, &records)
+}
+
+func (r *FetchResponse) AddControlRecordWithTimestamp(topic string, partition int32, offset int64, producerID int64, recordType ControlRecordType, timestamp time.Time) {
+	frb := r.getOrCreateBlock(topic, partition)
+
+	// batch
+	batch := &RecordBatch{
+		Version:         2,
+		LogAppendTime:   r.LogAppendTime,
+		FirstTimestamp:  timestamp,
+		MaxTimestamp:    r.Timestamp,
+		FirstOffset:     offset,
+		LastOffsetDelta: 0,
+		ProducerID:      producerID,
+		IsTransactional: true,
+		Control:         true,
+	}
+
+	// records
+	records := newDefaultRecords(nil)
+	records.RecordBatch = batch
+
+	// record
+	crAbort := ControlRecord{
+		Version: 0,
+		Type:    recordType,
+	}
+	crKey := &realEncoder{raw: make([]byte, 4)}
+	crValue := &realEncoder{raw: make([]byte, 6)}
+	crAbort.encode(crKey, crValue)
+	rec := &Record{Key: ByteEncoder(crKey.raw), Value: ByteEncoder(crValue.raw), OffsetDelta: 0, TimestampDelta: timestamp.Sub(batch.FirstTimestamp)}
+	batch.addRecord(rec)
+
+	frb.RecordsSet = append(frb.RecordsSet, &records)
+}
+
+func (r *FetchResponse) AddMessage(topic string, partition int32, key, value Encoder, offset int64) {
+	r.AddMessageWithTimestamp(topic, partition, key, value, offset, time.Time{}, 0)
+}
+
+func (r *FetchResponse) AddRecord(topic string, partition int32, key, value Encoder, offset int64) {
+	r.AddRecordWithTimestamp(topic, partition, key, value, offset, time.Time{})
+}
+
+func (r *FetchResponse) AddRecordBatch(topic string, partition int32, key, value Encoder, offset int64, producerID int64, isTransactional bool) {
+	r.AddRecordBatchWithTimestamp(topic, partition, key, value, offset, producerID, isTransactional, time.Time{})
+}
+
+func (r *FetchResponse) AddControlRecord(topic string, partition int32, offset int64, producerID int64, recordType ControlRecordType) {
+	// define controlRecord key and value
+	r.AddControlRecordWithTimestamp(topic, partition, offset, producerID, recordType, time.Time{})
+}
+
+func (r *FetchResponse) SetLastOffsetDelta(topic string, partition int32, offset int32) {
+	frb := r.getOrCreateBlock(topic, partition)
+	if len(frb.RecordsSet) == 0 {
+		records := newDefaultRecords(&RecordBatch{Version: 2})
+		frb.RecordsSet = []*Records{&records}
+	}
+	batch := frb.RecordsSet[0].RecordBatch
+	batch.LastOffsetDelta = offset
+}
+
+func (r *FetchResponse) SetLastStableOffset(topic string, partition int32, offset int64) {
+	frb := r.getOrCreateBlock(topic, partition)
+	frb.LastStableOffset = offset
+}
diff --git a/vendor/github.com/Shopify/sarama/find_coordinator_request.go b/vendor/github.com/Shopify/sarama/find_coordinator_request.go
new file mode 100644
index 0000000..ff2ad20
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/find_coordinator_request.go
@@ -0,0 +1,61 @@
+package sarama
+
+type CoordinatorType int8
+
+const (
+	CoordinatorGroup CoordinatorType = iota
+	CoordinatorTransaction
+)
+
+type FindCoordinatorRequest struct {
+	Version         int16
+	CoordinatorKey  string
+	CoordinatorType CoordinatorType
+}
+
+func (f *FindCoordinatorRequest) encode(pe packetEncoder) error {
+	if err := pe.putString(f.CoordinatorKey); err != nil {
+		return err
+	}
+
+	if f.Version >= 1 {
+		pe.putInt8(int8(f.CoordinatorType))
+	}
+
+	return nil
+}
+
+func (f *FindCoordinatorRequest) decode(pd packetDecoder, version int16) (err error) {
+	if f.CoordinatorKey, err = pd.getString(); err != nil {
+		return err
+	}
+
+	if version >= 1 {
+		f.Version = version
+		coordinatorType, err := pd.getInt8()
+		if err != nil {
+			return err
+		}
+
+		f.CoordinatorType = CoordinatorType(coordinatorType)
+	}
+
+	return nil
+}
+
+func (f *FindCoordinatorRequest) key() int16 {
+	return 10
+}
+
+func (f *FindCoordinatorRequest) version() int16 {
+	return f.Version
+}
+
+func (f *FindCoordinatorRequest) requiredVersion() KafkaVersion {
+	switch f.Version {
+	case 1:
+		return V0_11_0_0
+	default:
+		return V0_8_2_0
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/find_coordinator_response.go b/vendor/github.com/Shopify/sarama/find_coordinator_response.go
new file mode 100644
index 0000000..9c900e8
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/find_coordinator_response.go
@@ -0,0 +1,92 @@
+package sarama
+
+import (
+	"time"
+)
+
+var NoNode = &Broker{id: -1, addr: ":-1"}
+
+type FindCoordinatorResponse struct {
+	Version      int16
+	ThrottleTime time.Duration
+	Err          KError
+	ErrMsg       *string
+	Coordinator  *Broker
+}
+
+func (f *FindCoordinatorResponse) decode(pd packetDecoder, version int16) (err error) {
+	if version >= 1 {
+		f.Version = version
+
+		throttleTime, err := pd.getInt32()
+		if err != nil {
+			return err
+		}
+		f.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+	}
+
+	tmp, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	f.Err = KError(tmp)
+
+	if version >= 1 {
+		if f.ErrMsg, err = pd.getNullableString(); err != nil {
+			return err
+		}
+	}
+
+	coordinator := new(Broker)
+	// The version is hardcoded to 0, as version 1 of the Broker-decode
+	// contains the rack-field which is not present in the FindCoordinatorResponse.
+	if err := coordinator.decode(pd, 0); err != nil {
+		return err
+	}
+	if coordinator.addr == ":0" {
+		return nil
+	}
+	f.Coordinator = coordinator
+
+	return nil
+}
+
+func (f *FindCoordinatorResponse) encode(pe packetEncoder) error {
+	if f.Version >= 1 {
+		pe.putInt32(int32(f.ThrottleTime / time.Millisecond))
+	}
+
+	pe.putInt16(int16(f.Err))
+
+	if f.Version >= 1 {
+		if err := pe.putNullableString(f.ErrMsg); err != nil {
+			return err
+		}
+	}
+
+	coordinator := f.Coordinator
+	if coordinator == nil {
+		coordinator = NoNode
+	}
+	if err := coordinator.encode(pe, 0); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (f *FindCoordinatorResponse) key() int16 {
+	return 10
+}
+
+func (f *FindCoordinatorResponse) version() int16 {
+	return f.Version
+}
+
+func (f *FindCoordinatorResponse) requiredVersion() KafkaVersion {
+	switch f.Version {
+	case 1:
+		return V0_11_0_0
+	default:
+		return V0_8_2_0
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/go.mod b/vendor/github.com/Shopify/sarama/go.mod
new file mode 100644
index 0000000..8ba2c91
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/go.mod
@@ -0,0 +1,29 @@
+module github.com/Shopify/sarama
+
+go 1.13
+
+require (
+	github.com/Shopify/toxiproxy v2.1.4+incompatible
+	github.com/davecgh/go-spew v1.1.1
+	github.com/eapache/go-resiliency v1.1.0
+	github.com/eapache/go-xerial-snappy v0.0.0-20180814174437-776d5712da21
+	github.com/eapache/queue v1.1.0
+	github.com/fortytw2/leaktest v1.3.0
+	github.com/frankban/quicktest v1.4.1 // indirect
+	github.com/golang/snappy v0.0.1 // indirect
+	github.com/hashicorp/go-uuid v1.0.1 // indirect
+	github.com/jcmturner/gofork v0.0.0-20190328161633-dc7c13fece03 // indirect
+	github.com/klauspost/compress v1.9.7
+	github.com/pierrec/lz4 v2.2.6+incompatible
+	github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a
+	github.com/stretchr/testify v1.3.0
+	github.com/xdg/scram v0.0.0-20180814205039-7eeb5667e42c
+	github.com/xdg/stringprep v1.0.0 // indirect
+	golang.org/x/crypto v0.0.0-20190404164418-38d8ce5564a5 // indirect
+	golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3
+	gopkg.in/jcmturner/aescts.v1 v1.0.1 // indirect
+	gopkg.in/jcmturner/dnsutils.v1 v1.0.1 // indirect
+	gopkg.in/jcmturner/goidentity.v3 v3.0.0 // indirect
+	gopkg.in/jcmturner/gokrb5.v7 v7.2.3
+	gopkg.in/jcmturner/rpc.v1 v1.1.0 // indirect
+)
diff --git a/vendor/github.com/Shopify/sarama/go.sum b/vendor/github.com/Shopify/sarama/go.sum
new file mode 100644
index 0000000..7f61258
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/go.sum
@@ -0,0 +1,69 @@
+github.com/DataDog/zstd v1.4.0 h1:vhoV+DUHnRZdKW1i5UMjAk2G4JY8wN4ayRfYDNdEhwo=
+github.com/DataDog/zstd v1.4.0/go.mod h1:1jcaCB/ufaK+sKp1NBhlGmpz41jOoPQ35bpF36t7BBo=
+github.com/Shopify/toxiproxy v2.1.4+incompatible h1:TKdv8HiTLgE5wdJuEML90aBgNWsokNbMijUGhmcoBJc=
+github.com/Shopify/toxiproxy v2.1.4+incompatible/go.mod h1:OXgGpZ6Cli1/URJOF1DMxUHB2q5Ap20/P/eIdh4G0pI=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
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+github.com/eapache/go-resiliency v1.1.0 h1:1NtRmCAqadE2FN4ZcN6g90TP3uk8cg9rn9eNK2197aU=
+github.com/eapache/go-resiliency v1.1.0/go.mod h1:kFI+JgMyC7bLPUVY133qvEBtVayf5mFgVsvEsIPBvNs=
+github.com/eapache/go-xerial-snappy v0.0.0-20180814174437-776d5712da21 h1:YEetp8/yCZMuEPMUDHG0CW/brkkEp8mzqk2+ODEitlw=
+github.com/eapache/go-xerial-snappy v0.0.0-20180814174437-776d5712da21/go.mod h1:+020luEh2TKB4/GOp8oxxtq0Daoen/Cii55CzbTV6DU=
+github.com/eapache/queue v1.1.0 h1:YOEu7KNc61ntiQlcEeUIoDTJ2o8mQznoNvUhiigpIqc=
+github.com/eapache/queue v1.1.0/go.mod h1:6eCeP0CKFpHLu8blIFXhExK/dRa7WDZfr6jVFPTqq+I=
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+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2 h1:VklqNMn3ovrHsnt90PveolxSbWFaJdECFbxSq0Mqo2M=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190404164418-38d8ce5564a5 h1:bselrhR0Or1vomJZC8ZIjWtbDmn9OYFLX5Ik9alpJpE=
+golang.org/x/crypto v0.0.0-20190404164418-38d8ce5564a5/go.mod h1:WFFai1msRO1wXaEeE5yQxYXgSfI8pQAWXbQop6sCtWE=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190403152447-81d4e9dc473e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+gopkg.in/jcmturner/aescts.v1 v1.0.1 h1:cVVZBK2b1zY26haWB4vbBiZrfFQnfbTVrE3xZq6hrEw=
+gopkg.in/jcmturner/aescts.v1 v1.0.1/go.mod h1:nsR8qBOg+OucoIW+WMhB3GspUQXq9XorLnQb9XtvcOo=
+gopkg.in/jcmturner/dnsutils.v1 v1.0.1 h1:cIuC1OLRGZrld+16ZJvvZxVJeKPsvd5eUIvxfoN5hSM=
+gopkg.in/jcmturner/dnsutils.v1 v1.0.1/go.mod h1:m3v+5svpVOhtFAP/wSz+yzh4Mc0Fg7eRhxkJMWSIz9Q=
+gopkg.in/jcmturner/goidentity.v3 v3.0.0 h1:1duIyWiTaYvVx3YX2CYtpJbUFd7/UuPYCfgXtQ3VTbI=
+gopkg.in/jcmturner/goidentity.v3 v3.0.0/go.mod h1:oG2kH0IvSYNIu80dVAyu/yoefjq1mNfM5bm88whjWx4=
+gopkg.in/jcmturner/gokrb5.v7 v7.2.3 h1:hHMV/yKPwMnJhPuPx7pH2Uw/3Qyf+thJYlisUc44010=
+gopkg.in/jcmturner/gokrb5.v7 v7.2.3/go.mod h1:l8VISx+WGYp+Fp7KRbsiUuXTTOnxIc3Tuvyavf11/WM=
+gopkg.in/jcmturner/rpc.v1 v1.1.0 h1:QHIUxTX1ISuAv9dD2wJ9HWQVuWDX/Zc0PfeC2tjc4rU=
+gopkg.in/jcmturner/rpc.v1 v1.1.0/go.mod h1:YIdkC4XfD6GXbzje11McwsDuOlZQSb9W4vfLvuNnlv8=
diff --git a/vendor/github.com/Shopify/sarama/gssapi_kerberos.go b/vendor/github.com/Shopify/sarama/gssapi_kerberos.go
new file mode 100644
index 0000000..57f3ecb
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/gssapi_kerberos.go
@@ -0,0 +1,258 @@
+package sarama
+
+import (
+	"encoding/asn1"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"strings"
+	"time"
+
+	"gopkg.in/jcmturner/gokrb5.v7/asn1tools"
+	"gopkg.in/jcmturner/gokrb5.v7/gssapi"
+	"gopkg.in/jcmturner/gokrb5.v7/iana/chksumtype"
+	"gopkg.in/jcmturner/gokrb5.v7/iana/keyusage"
+	"gopkg.in/jcmturner/gokrb5.v7/messages"
+	"gopkg.in/jcmturner/gokrb5.v7/types"
+)
+
+const (
+	TOK_ID_KRB_AP_REQ   = 256
+	GSS_API_GENERIC_TAG = 0x60
+	KRB5_USER_AUTH      = 1
+	KRB5_KEYTAB_AUTH    = 2
+	GSS_API_INITIAL     = 1
+	GSS_API_VERIFY      = 2
+	GSS_API_FINISH      = 3
+)
+
+type GSSAPIConfig struct {
+	AuthType           int
+	KeyTabPath         string
+	KerberosConfigPath string
+	ServiceName        string
+	Username           string
+	Password           string
+	Realm              string
+}
+
+type GSSAPIKerberosAuth struct {
+	Config                *GSSAPIConfig
+	ticket                messages.Ticket
+	encKey                types.EncryptionKey
+	NewKerberosClientFunc func(config *GSSAPIConfig) (KerberosClient, error)
+	step                  int
+}
+
+type KerberosClient interface {
+	Login() error
+	GetServiceTicket(spn string) (messages.Ticket, types.EncryptionKey, error)
+	Domain() string
+	CName() types.PrincipalName
+	Destroy()
+}
+
+/*
+*
+* Appends length in big endian before payload, and send it to kafka
+*
+ */
+
+func (krbAuth *GSSAPIKerberosAuth) writePackage(broker *Broker, payload []byte) (int, error) {
+	length := len(payload)
+	finalPackage := make([]byte, length+4) //4 byte length header + payload
+	copy(finalPackage[4:], payload)
+	binary.BigEndian.PutUint32(finalPackage, uint32(length))
+	bytes, err := broker.conn.Write(finalPackage)
+	if err != nil {
+		return bytes, err
+	}
+	return bytes, nil
+}
+
+/*
+*
+* Read length (4 bytes) and then read the payload
+*
+ */
+
+func (krbAuth *GSSAPIKerberosAuth) readPackage(broker *Broker) ([]byte, int, error) {
+	bytesRead := 0
+	lengthInBytes := make([]byte, 4)
+	bytes, err := io.ReadFull(broker.conn, lengthInBytes)
+	if err != nil {
+		return nil, bytesRead, err
+	}
+	bytesRead += bytes
+	payloadLength := binary.BigEndian.Uint32(lengthInBytes)
+	payloadBytes := make([]byte, payloadLength)         // buffer for read..
+	bytes, err = io.ReadFull(broker.conn, payloadBytes) // read bytes
+	if err != nil {
+		return payloadBytes, bytesRead, err
+	}
+	bytesRead += bytes
+	return payloadBytes, bytesRead, nil
+}
+
+func (krbAuth *GSSAPIKerberosAuth) newAuthenticatorChecksum() []byte {
+	a := make([]byte, 24)
+	flags := []int{gssapi.ContextFlagInteg, gssapi.ContextFlagConf}
+	binary.LittleEndian.PutUint32(a[:4], 16)
+	for _, i := range flags {
+		f := binary.LittleEndian.Uint32(a[20:24])
+		f |= uint32(i)
+		binary.LittleEndian.PutUint32(a[20:24], f)
+	}
+	return a
+}
+
+/*
+*
+* Construct Kerberos AP_REQ package, conforming to RFC-4120
+* https://tools.ietf.org/html/rfc4120#page-84
+*
+ */
+func (krbAuth *GSSAPIKerberosAuth) createKrb5Token(
+	domain string, cname types.PrincipalName,
+	ticket messages.Ticket,
+	sessionKey types.EncryptionKey) ([]byte, error) {
+	auth, err := types.NewAuthenticator(domain, cname)
+	if err != nil {
+		return nil, err
+	}
+	auth.Cksum = types.Checksum{
+		CksumType: chksumtype.GSSAPI,
+		Checksum:  krbAuth.newAuthenticatorChecksum(),
+	}
+	APReq, err := messages.NewAPReq(
+		ticket,
+		sessionKey,
+		auth,
+	)
+	if err != nil {
+		return nil, err
+	}
+	aprBytes := make([]byte, 2)
+	binary.BigEndian.PutUint16(aprBytes, TOK_ID_KRB_AP_REQ)
+	tb, err := APReq.Marshal()
+	if err != nil {
+		return nil, err
+	}
+	aprBytes = append(aprBytes, tb...)
+	return aprBytes, nil
+}
+
+/*
+*
+*	Append the GSS-API header to the payload, conforming to RFC-2743
+*	Section 3.1, Mechanism-Independent Token Format
+*
+*	https://tools.ietf.org/html/rfc2743#page-81
+*
+*	GSSAPIHeader + <specific mechanism payload>
+*
+ */
+func (krbAuth *GSSAPIKerberosAuth) appendGSSAPIHeader(payload []byte) ([]byte, error) {
+	oidBytes, err := asn1.Marshal(gssapi.OID(gssapi.OIDKRB5))
+	if err != nil {
+		return nil, err
+	}
+	tkoLengthBytes := asn1tools.MarshalLengthBytes(len(oidBytes) + len(payload))
+	GSSHeader := append([]byte{GSS_API_GENERIC_TAG}, tkoLengthBytes...)
+	GSSHeader = append(GSSHeader, oidBytes...)
+	GSSPackage := append(GSSHeader, payload...)
+	return GSSPackage, nil
+}
+
+func (krbAuth *GSSAPIKerberosAuth) initSecContext(bytes []byte, kerberosClient KerberosClient) ([]byte, error) {
+	switch krbAuth.step {
+	case GSS_API_INITIAL:
+		aprBytes, err := krbAuth.createKrb5Token(
+			kerberosClient.Domain(),
+			kerberosClient.CName(),
+			krbAuth.ticket,
+			krbAuth.encKey)
+		if err != nil {
+			return nil, err
+		}
+		krbAuth.step = GSS_API_VERIFY
+		return krbAuth.appendGSSAPIHeader(aprBytes)
+	case GSS_API_VERIFY:
+		wrapTokenReq := gssapi.WrapToken{}
+		if err := wrapTokenReq.Unmarshal(bytes, true); err != nil {
+			return nil, err
+		}
+		// Validate response.
+		isValid, err := wrapTokenReq.Verify(krbAuth.encKey, keyusage.GSSAPI_ACCEPTOR_SEAL)
+		if !isValid {
+			return nil, err
+		}
+
+		wrapTokenResponse, err := gssapi.NewInitiatorWrapToken(wrapTokenReq.Payload, krbAuth.encKey)
+		if err != nil {
+			return nil, err
+		}
+		krbAuth.step = GSS_API_FINISH
+		return wrapTokenResponse.Marshal()
+	}
+	return nil, nil
+}
+
+/* This does the handshake for authorization */
+func (krbAuth *GSSAPIKerberosAuth) Authorize(broker *Broker) error {
+
+	kerberosClient, err := krbAuth.NewKerberosClientFunc(krbAuth.Config)
+	if err != nil {
+		Logger.Printf("Kerberos client error: %s", err)
+		return err
+	}
+
+	err = kerberosClient.Login()
+	if err != nil {
+		Logger.Printf("Kerberos client error: %s", err)
+		return err
+	}
+	// Construct SPN using serviceName and host
+	// SPN format: <SERVICE>/<FQDN>
+
+	host := strings.SplitN(broker.addr, ":", 2)[0] // Strip port part
+	spn := fmt.Sprintf("%s/%s", broker.conf.Net.SASL.GSSAPI.ServiceName, host)
+
+	ticket, encKey, err := kerberosClient.GetServiceTicket(spn)
+
+	if err != nil {
+		Logger.Printf("Error getting Kerberos service ticket : %s", err)
+		return err
+	}
+	krbAuth.ticket = ticket
+	krbAuth.encKey = encKey
+	krbAuth.step = GSS_API_INITIAL
+	var receivedBytes []byte = nil
+	defer kerberosClient.Destroy()
+	for {
+		packBytes, err := krbAuth.initSecContext(receivedBytes, kerberosClient)
+		if err != nil {
+			Logger.Printf("Error while performing GSSAPI Kerberos Authentication: %s\n", err)
+			return err
+		}
+		requestTime := time.Now()
+		bytesWritten, err := krbAuth.writePackage(broker, packBytes)
+		if err != nil {
+			Logger.Printf("Error while performing GSSAPI Kerberos Authentication: %s\n", err)
+			return err
+		}
+		broker.updateOutgoingCommunicationMetrics(bytesWritten)
+		if krbAuth.step == GSS_API_VERIFY {
+			var bytesRead = 0
+			receivedBytes, bytesRead, err = krbAuth.readPackage(broker)
+			requestLatency := time.Since(requestTime)
+			broker.updateIncomingCommunicationMetrics(bytesRead, requestLatency)
+			if err != nil {
+				Logger.Printf("Error while performing GSSAPI Kerberos Authentication: %s\n", err)
+				return err
+			}
+		} else if krbAuth.step == GSS_API_FINISH {
+			return nil
+		}
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/heartbeat_request.go b/vendor/github.com/Shopify/sarama/heartbeat_request.go
new file mode 100644
index 0000000..ce49c47
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/heartbeat_request.go
@@ -0,0 +1,47 @@
+package sarama
+
+type HeartbeatRequest struct {
+	GroupId      string
+	GenerationId int32
+	MemberId     string
+}
+
+func (r *HeartbeatRequest) encode(pe packetEncoder) error {
+	if err := pe.putString(r.GroupId); err != nil {
+		return err
+	}
+
+	pe.putInt32(r.GenerationId)
+
+	if err := pe.putString(r.MemberId); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *HeartbeatRequest) decode(pd packetDecoder, version int16) (err error) {
+	if r.GroupId, err = pd.getString(); err != nil {
+		return
+	}
+	if r.GenerationId, err = pd.getInt32(); err != nil {
+		return
+	}
+	if r.MemberId, err = pd.getString(); err != nil {
+		return
+	}
+
+	return nil
+}
+
+func (r *HeartbeatRequest) key() int16 {
+	return 12
+}
+
+func (r *HeartbeatRequest) version() int16 {
+	return 0
+}
+
+func (r *HeartbeatRequest) requiredVersion() KafkaVersion {
+	return V0_9_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/heartbeat_response.go b/vendor/github.com/Shopify/sarama/heartbeat_response.go
new file mode 100644
index 0000000..766f5fd
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/heartbeat_response.go
@@ -0,0 +1,32 @@
+package sarama
+
+type HeartbeatResponse struct {
+	Err KError
+}
+
+func (r *HeartbeatResponse) encode(pe packetEncoder) error {
+	pe.putInt16(int16(r.Err))
+	return nil
+}
+
+func (r *HeartbeatResponse) decode(pd packetDecoder, version int16) error {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	r.Err = KError(kerr)
+
+	return nil
+}
+
+func (r *HeartbeatResponse) key() int16 {
+	return 12
+}
+
+func (r *HeartbeatResponse) version() int16 {
+	return 0
+}
+
+func (r *HeartbeatResponse) requiredVersion() KafkaVersion {
+	return V0_9_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/init_producer_id_request.go b/vendor/github.com/Shopify/sarama/init_producer_id_request.go
new file mode 100644
index 0000000..8ceb6c2
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/init_producer_id_request.go
@@ -0,0 +1,43 @@
+package sarama
+
+import "time"
+
+type InitProducerIDRequest struct {
+	TransactionalID    *string
+	TransactionTimeout time.Duration
+}
+
+func (i *InitProducerIDRequest) encode(pe packetEncoder) error {
+	if err := pe.putNullableString(i.TransactionalID); err != nil {
+		return err
+	}
+	pe.putInt32(int32(i.TransactionTimeout / time.Millisecond))
+
+	return nil
+}
+
+func (i *InitProducerIDRequest) decode(pd packetDecoder, version int16) (err error) {
+	if i.TransactionalID, err = pd.getNullableString(); err != nil {
+		return err
+	}
+
+	timeout, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	i.TransactionTimeout = time.Duration(timeout) * time.Millisecond
+
+	return nil
+}
+
+func (i *InitProducerIDRequest) key() int16 {
+	return 22
+}
+
+func (i *InitProducerIDRequest) version() int16 {
+	return 0
+}
+
+func (i *InitProducerIDRequest) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/init_producer_id_response.go b/vendor/github.com/Shopify/sarama/init_producer_id_response.go
new file mode 100644
index 0000000..1b32eb0
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/init_producer_id_response.go
@@ -0,0 +1,55 @@
+package sarama
+
+import "time"
+
+type InitProducerIDResponse struct {
+	ThrottleTime  time.Duration
+	Err           KError
+	ProducerID    int64
+	ProducerEpoch int16
+}
+
+func (i *InitProducerIDResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(i.ThrottleTime / time.Millisecond))
+	pe.putInt16(int16(i.Err))
+	pe.putInt64(i.ProducerID)
+	pe.putInt16(i.ProducerEpoch)
+
+	return nil
+}
+
+func (i *InitProducerIDResponse) decode(pd packetDecoder, version int16) (err error) {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	i.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	i.Err = KError(kerr)
+
+	if i.ProducerID, err = pd.getInt64(); err != nil {
+		return err
+	}
+
+	if i.ProducerEpoch, err = pd.getInt16(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (i *InitProducerIDResponse) key() int16 {
+	return 22
+}
+
+func (i *InitProducerIDResponse) version() int16 {
+	return 0
+}
+
+func (i *InitProducerIDResponse) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/join_group_request.go b/vendor/github.com/Shopify/sarama/join_group_request.go
new file mode 100644
index 0000000..97e9299
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/join_group_request.go
@@ -0,0 +1,163 @@
+package sarama
+
+type GroupProtocol struct {
+	Name     string
+	Metadata []byte
+}
+
+func (p *GroupProtocol) decode(pd packetDecoder) (err error) {
+	p.Name, err = pd.getString()
+	if err != nil {
+		return err
+	}
+	p.Metadata, err = pd.getBytes()
+	return err
+}
+
+func (p *GroupProtocol) encode(pe packetEncoder) (err error) {
+	if err := pe.putString(p.Name); err != nil {
+		return err
+	}
+	if err := pe.putBytes(p.Metadata); err != nil {
+		return err
+	}
+	return nil
+}
+
+type JoinGroupRequest struct {
+	Version               int16
+	GroupId               string
+	SessionTimeout        int32
+	RebalanceTimeout      int32
+	MemberId              string
+	ProtocolType          string
+	GroupProtocols        map[string][]byte // deprecated; use OrderedGroupProtocols
+	OrderedGroupProtocols []*GroupProtocol
+}
+
+func (r *JoinGroupRequest) encode(pe packetEncoder) error {
+	if err := pe.putString(r.GroupId); err != nil {
+		return err
+	}
+	pe.putInt32(r.SessionTimeout)
+	if r.Version >= 1 {
+		pe.putInt32(r.RebalanceTimeout)
+	}
+	if err := pe.putString(r.MemberId); err != nil {
+		return err
+	}
+	if err := pe.putString(r.ProtocolType); err != nil {
+		return err
+	}
+
+	if len(r.GroupProtocols) > 0 {
+		if len(r.OrderedGroupProtocols) > 0 {
+			return PacketDecodingError{"cannot specify both GroupProtocols and OrderedGroupProtocols on JoinGroupRequest"}
+		}
+
+		if err := pe.putArrayLength(len(r.GroupProtocols)); err != nil {
+			return err
+		}
+		for name, metadata := range r.GroupProtocols {
+			if err := pe.putString(name); err != nil {
+				return err
+			}
+			if err := pe.putBytes(metadata); err != nil {
+				return err
+			}
+		}
+	} else {
+		if err := pe.putArrayLength(len(r.OrderedGroupProtocols)); err != nil {
+			return err
+		}
+		for _, protocol := range r.OrderedGroupProtocols {
+			if err := protocol.encode(pe); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (r *JoinGroupRequest) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+
+	if r.GroupId, err = pd.getString(); err != nil {
+		return
+	}
+
+	if r.SessionTimeout, err = pd.getInt32(); err != nil {
+		return
+	}
+
+	if version >= 1 {
+		if r.RebalanceTimeout, err = pd.getInt32(); err != nil {
+			return err
+		}
+	}
+
+	if r.MemberId, err = pd.getString(); err != nil {
+		return
+	}
+
+	if r.ProtocolType, err = pd.getString(); err != nil {
+		return
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if n == 0 {
+		return nil
+	}
+
+	r.GroupProtocols = make(map[string][]byte)
+	for i := 0; i < n; i++ {
+		protocol := &GroupProtocol{}
+		if err := protocol.decode(pd); err != nil {
+			return err
+		}
+		r.GroupProtocols[protocol.Name] = protocol.Metadata
+		r.OrderedGroupProtocols = append(r.OrderedGroupProtocols, protocol)
+	}
+
+	return nil
+}
+
+func (r *JoinGroupRequest) key() int16 {
+	return 11
+}
+
+func (r *JoinGroupRequest) version() int16 {
+	return r.Version
+}
+
+func (r *JoinGroupRequest) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 2:
+		return V0_11_0_0
+	case 1:
+		return V0_10_1_0
+	default:
+		return V0_9_0_0
+	}
+}
+
+func (r *JoinGroupRequest) AddGroupProtocol(name string, metadata []byte) {
+	r.OrderedGroupProtocols = append(r.OrderedGroupProtocols, &GroupProtocol{
+		Name:     name,
+		Metadata: metadata,
+	})
+}
+
+func (r *JoinGroupRequest) AddGroupProtocolMetadata(name string, metadata *ConsumerGroupMemberMetadata) error {
+	bin, err := encode(metadata, nil)
+	if err != nil {
+		return err
+	}
+
+	r.AddGroupProtocol(name, bin)
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/join_group_response.go b/vendor/github.com/Shopify/sarama/join_group_response.go
new file mode 100644
index 0000000..5752acc
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/join_group_response.go
@@ -0,0 +1,135 @@
+package sarama
+
+type JoinGroupResponse struct {
+	Version       int16
+	ThrottleTime  int32
+	Err           KError
+	GenerationId  int32
+	GroupProtocol string
+	LeaderId      string
+	MemberId      string
+	Members       map[string][]byte
+}
+
+func (r *JoinGroupResponse) GetMembers() (map[string]ConsumerGroupMemberMetadata, error) {
+	members := make(map[string]ConsumerGroupMemberMetadata, len(r.Members))
+	for id, bin := range r.Members {
+		meta := new(ConsumerGroupMemberMetadata)
+		if err := decode(bin, meta); err != nil {
+			return nil, err
+		}
+		members[id] = *meta
+	}
+	return members, nil
+}
+
+func (r *JoinGroupResponse) encode(pe packetEncoder) error {
+	if r.Version >= 2 {
+		pe.putInt32(r.ThrottleTime)
+	}
+	pe.putInt16(int16(r.Err))
+	pe.putInt32(r.GenerationId)
+
+	if err := pe.putString(r.GroupProtocol); err != nil {
+		return err
+	}
+	if err := pe.putString(r.LeaderId); err != nil {
+		return err
+	}
+	if err := pe.putString(r.MemberId); err != nil {
+		return err
+	}
+
+	if err := pe.putArrayLength(len(r.Members)); err != nil {
+		return err
+	}
+
+	for memberId, memberMetadata := range r.Members {
+		if err := pe.putString(memberId); err != nil {
+			return err
+		}
+
+		if err := pe.putBytes(memberMetadata); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *JoinGroupResponse) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+
+	if version >= 2 {
+		if r.ThrottleTime, err = pd.getInt32(); err != nil {
+			return
+		}
+	}
+
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+
+	r.Err = KError(kerr)
+
+	if r.GenerationId, err = pd.getInt32(); err != nil {
+		return
+	}
+
+	if r.GroupProtocol, err = pd.getString(); err != nil {
+		return
+	}
+
+	if r.LeaderId, err = pd.getString(); err != nil {
+		return
+	}
+
+	if r.MemberId, err = pd.getString(); err != nil {
+		return
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if n == 0 {
+		return nil
+	}
+
+	r.Members = make(map[string][]byte)
+	for i := 0; i < n; i++ {
+		memberId, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		memberMetadata, err := pd.getBytes()
+		if err != nil {
+			return err
+		}
+
+		r.Members[memberId] = memberMetadata
+	}
+
+	return nil
+}
+
+func (r *JoinGroupResponse) key() int16 {
+	return 11
+}
+
+func (r *JoinGroupResponse) version() int16 {
+	return r.Version
+}
+
+func (r *JoinGroupResponse) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 2:
+		return V0_11_0_0
+	case 1:
+		return V0_10_1_0
+	default:
+		return V0_9_0_0
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/kerberos_client.go b/vendor/github.com/Shopify/sarama/kerberos_client.go
new file mode 100644
index 0000000..91b998f
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/kerberos_client.go
@@ -0,0 +1,51 @@
+package sarama
+
+import (
+	krb5client "gopkg.in/jcmturner/gokrb5.v7/client"
+	krb5config "gopkg.in/jcmturner/gokrb5.v7/config"
+	"gopkg.in/jcmturner/gokrb5.v7/keytab"
+	"gopkg.in/jcmturner/gokrb5.v7/types"
+)
+
+type KerberosGoKrb5Client struct {
+	krb5client.Client
+}
+
+func (c *KerberosGoKrb5Client) Domain() string {
+	return c.Credentials.Domain()
+}
+
+func (c *KerberosGoKrb5Client) CName() types.PrincipalName {
+	return c.Credentials.CName()
+}
+
+/*
+*
+* Create kerberos client used to obtain TGT and TGS tokens
+* used gokrb5 library, which is a pure go kerberos client with
+* some GSS-API capabilities, and SPNEGO support. Kafka does not use SPNEGO
+* it uses pure Kerberos 5 solution (RFC-4121 and RFC-4120).
+*
+ */
+func NewKerberosClient(config *GSSAPIConfig) (KerberosClient, error) {
+	cfg, err := krb5config.Load(config.KerberosConfigPath)
+	if err != nil {
+		return nil, err
+	}
+	return createClient(config, cfg)
+}
+
+func createClient(config *GSSAPIConfig, cfg *krb5config.Config) (KerberosClient, error) {
+	var client *krb5client.Client
+	if config.AuthType == KRB5_KEYTAB_AUTH {
+		kt, err := keytab.Load(config.KeyTabPath)
+		if err != nil {
+			return nil, err
+		}
+		client = krb5client.NewClientWithKeytab(config.Username, config.Realm, kt, cfg)
+	} else {
+		client = krb5client.NewClientWithPassword(config.Username,
+			config.Realm, config.Password, cfg)
+	}
+	return &KerberosGoKrb5Client{*client}, nil
+}
diff --git a/vendor/github.com/Shopify/sarama/leave_group_request.go b/vendor/github.com/Shopify/sarama/leave_group_request.go
new file mode 100644
index 0000000..e177427
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/leave_group_request.go
@@ -0,0 +1,40 @@
+package sarama
+
+type LeaveGroupRequest struct {
+	GroupId  string
+	MemberId string
+}
+
+func (r *LeaveGroupRequest) encode(pe packetEncoder) error {
+	if err := pe.putString(r.GroupId); err != nil {
+		return err
+	}
+	if err := pe.putString(r.MemberId); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *LeaveGroupRequest) decode(pd packetDecoder, version int16) (err error) {
+	if r.GroupId, err = pd.getString(); err != nil {
+		return
+	}
+	if r.MemberId, err = pd.getString(); err != nil {
+		return
+	}
+
+	return nil
+}
+
+func (r *LeaveGroupRequest) key() int16 {
+	return 13
+}
+
+func (r *LeaveGroupRequest) version() int16 {
+	return 0
+}
+
+func (r *LeaveGroupRequest) requiredVersion() KafkaVersion {
+	return V0_9_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/leave_group_response.go b/vendor/github.com/Shopify/sarama/leave_group_response.go
new file mode 100644
index 0000000..d60c626
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/leave_group_response.go
@@ -0,0 +1,32 @@
+package sarama
+
+type LeaveGroupResponse struct {
+	Err KError
+}
+
+func (r *LeaveGroupResponse) encode(pe packetEncoder) error {
+	pe.putInt16(int16(r.Err))
+	return nil
+}
+
+func (r *LeaveGroupResponse) decode(pd packetDecoder, version int16) (err error) {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	r.Err = KError(kerr)
+
+	return nil
+}
+
+func (r *LeaveGroupResponse) key() int16 {
+	return 13
+}
+
+func (r *LeaveGroupResponse) version() int16 {
+	return 0
+}
+
+func (r *LeaveGroupResponse) requiredVersion() KafkaVersion {
+	return V0_9_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/length_field.go b/vendor/github.com/Shopify/sarama/length_field.go
new file mode 100644
index 0000000..7d864f6
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/length_field.go
@@ -0,0 +1,99 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"sync"
+)
+
+// LengthField implements the PushEncoder and PushDecoder interfaces for calculating 4-byte lengths.
+type lengthField struct {
+	startOffset int
+	length      int32
+}
+
+var lengthFieldPool = sync.Pool{}
+
+func acquireLengthField() *lengthField {
+	val := lengthFieldPool.Get()
+	if val != nil {
+		return val.(*lengthField)
+	}
+	return &lengthField{}
+}
+
+func releaseLengthField(m *lengthField) {
+	lengthFieldPool.Put(m)
+}
+
+func (l *lengthField) decode(pd packetDecoder) error {
+	var err error
+	l.length, err = pd.getInt32()
+	if err != nil {
+		return err
+	}
+	if l.length > int32(pd.remaining()) {
+		return ErrInsufficientData
+	}
+	return nil
+}
+
+func (l *lengthField) saveOffset(in int) {
+	l.startOffset = in
+}
+
+func (l *lengthField) reserveLength() int {
+	return 4
+}
+
+func (l *lengthField) run(curOffset int, buf []byte) error {
+	binary.BigEndian.PutUint32(buf[l.startOffset:], uint32(curOffset-l.startOffset-4))
+	return nil
+}
+
+func (l *lengthField) check(curOffset int, buf []byte) error {
+	if int32(curOffset-l.startOffset-4) != l.length {
+		return PacketDecodingError{"length field invalid"}
+	}
+
+	return nil
+}
+
+type varintLengthField struct {
+	startOffset int
+	length      int64
+}
+
+func (l *varintLengthField) decode(pd packetDecoder) error {
+	var err error
+	l.length, err = pd.getVarint()
+	return err
+}
+
+func (l *varintLengthField) saveOffset(in int) {
+	l.startOffset = in
+}
+
+func (l *varintLengthField) adjustLength(currOffset int) int {
+	oldFieldSize := l.reserveLength()
+	l.length = int64(currOffset - l.startOffset - oldFieldSize)
+
+	return l.reserveLength() - oldFieldSize
+}
+
+func (l *varintLengthField) reserveLength() int {
+	var tmp [binary.MaxVarintLen64]byte
+	return binary.PutVarint(tmp[:], l.length)
+}
+
+func (l *varintLengthField) run(curOffset int, buf []byte) error {
+	binary.PutVarint(buf[l.startOffset:], l.length)
+	return nil
+}
+
+func (l *varintLengthField) check(curOffset int, buf []byte) error {
+	if int64(curOffset-l.startOffset-l.reserveLength()) != l.length {
+		return PacketDecodingError{"length field invalid"}
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/list_groups_request.go b/vendor/github.com/Shopify/sarama/list_groups_request.go
new file mode 100644
index 0000000..3b16abf
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/list_groups_request.go
@@ -0,0 +1,24 @@
+package sarama
+
+type ListGroupsRequest struct {
+}
+
+func (r *ListGroupsRequest) encode(pe packetEncoder) error {
+	return nil
+}
+
+func (r *ListGroupsRequest) decode(pd packetDecoder, version int16) (err error) {
+	return nil
+}
+
+func (r *ListGroupsRequest) key() int16 {
+	return 16
+}
+
+func (r *ListGroupsRequest) version() int16 {
+	return 0
+}
+
+func (r *ListGroupsRequest) requiredVersion() KafkaVersion {
+	return V0_9_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/list_groups_response.go b/vendor/github.com/Shopify/sarama/list_groups_response.go
new file mode 100644
index 0000000..56115d4
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/list_groups_response.go
@@ -0,0 +1,69 @@
+package sarama
+
+type ListGroupsResponse struct {
+	Err    KError
+	Groups map[string]string
+}
+
+func (r *ListGroupsResponse) encode(pe packetEncoder) error {
+	pe.putInt16(int16(r.Err))
+
+	if err := pe.putArrayLength(len(r.Groups)); err != nil {
+		return err
+	}
+	for groupId, protocolType := range r.Groups {
+		if err := pe.putString(groupId); err != nil {
+			return err
+		}
+		if err := pe.putString(protocolType); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *ListGroupsResponse) decode(pd packetDecoder, version int16) error {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+
+	r.Err = KError(kerr)
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if n == 0 {
+		return nil
+	}
+
+	r.Groups = make(map[string]string)
+	for i := 0; i < n; i++ {
+		groupId, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		protocolType, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		r.Groups[groupId] = protocolType
+	}
+
+	return nil
+}
+
+func (r *ListGroupsResponse) key() int16 {
+	return 16
+}
+
+func (r *ListGroupsResponse) version() int16 {
+	return 0
+}
+
+func (r *ListGroupsResponse) requiredVersion() KafkaVersion {
+	return V0_9_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/message.go b/vendor/github.com/Shopify/sarama/message.go
new file mode 100644
index 0000000..7c54748
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/message.go
@@ -0,0 +1,175 @@
+package sarama
+
+import (
+	"fmt"
+	"time"
+)
+
+const (
+	//CompressionNone no compression
+	CompressionNone CompressionCodec = iota
+	//CompressionGZIP compression using GZIP
+	CompressionGZIP
+	//CompressionSnappy compression using snappy
+	CompressionSnappy
+	//CompressionLZ4 compression using LZ4
+	CompressionLZ4
+	//CompressionZSTD compression using ZSTD
+	CompressionZSTD
+
+	// The lowest 3 bits contain the compression codec used for the message
+	compressionCodecMask int8 = 0x07
+
+	// Bit 3 set for "LogAppend" timestamps
+	timestampTypeMask = 0x08
+
+	// CompressionLevelDefault is the constant to use in CompressionLevel
+	// to have the default compression level for any codec. The value is picked
+	// that we don't use any existing compression levels.
+	CompressionLevelDefault = -1000
+)
+
+// CompressionCodec represents the various compression codecs recognized by Kafka in messages.
+type CompressionCodec int8
+
+func (cc CompressionCodec) String() string {
+	return []string{
+		"none",
+		"gzip",
+		"snappy",
+		"lz4",
+		"zstd",
+	}[int(cc)]
+}
+
+//Message is a kafka message type
+type Message struct {
+	Codec            CompressionCodec // codec used to compress the message contents
+	CompressionLevel int              // compression level
+	LogAppendTime    bool             // the used timestamp is LogAppendTime
+	Key              []byte           // the message key, may be nil
+	Value            []byte           // the message contents
+	Set              *MessageSet      // the message set a message might wrap
+	Version          int8             // v1 requires Kafka 0.10
+	Timestamp        time.Time        // the timestamp of the message (version 1+ only)
+
+	compressedCache []byte
+	compressedSize  int // used for computing the compression ratio metrics
+}
+
+func (m *Message) encode(pe packetEncoder) error {
+	pe.push(newCRC32Field(crcIEEE))
+
+	pe.putInt8(m.Version)
+
+	attributes := int8(m.Codec) & compressionCodecMask
+	if m.LogAppendTime {
+		attributes |= timestampTypeMask
+	}
+	pe.putInt8(attributes)
+
+	if m.Version >= 1 {
+		if err := (Timestamp{&m.Timestamp}).encode(pe); err != nil {
+			return err
+		}
+	}
+
+	err := pe.putBytes(m.Key)
+	if err != nil {
+		return err
+	}
+
+	var payload []byte
+
+	if m.compressedCache != nil {
+		payload = m.compressedCache
+		m.compressedCache = nil
+	} else if m.Value != nil {
+
+		payload, err = compress(m.Codec, m.CompressionLevel, m.Value)
+		if err != nil {
+			return err
+		}
+		m.compressedCache = payload
+		// Keep in mind the compressed payload size for metric gathering
+		m.compressedSize = len(payload)
+	}
+
+	if err = pe.putBytes(payload); err != nil {
+		return err
+	}
+
+	return pe.pop()
+}
+
+func (m *Message) decode(pd packetDecoder) (err error) {
+	crc32Decoder := acquireCrc32Field(crcIEEE)
+	defer releaseCrc32Field(crc32Decoder)
+
+	err = pd.push(crc32Decoder)
+	if err != nil {
+		return err
+	}
+
+	m.Version, err = pd.getInt8()
+	if err != nil {
+		return err
+	}
+
+	if m.Version > 1 {
+		return PacketDecodingError{fmt.Sprintf("unknown magic byte (%v)", m.Version)}
+	}
+
+	attribute, err := pd.getInt8()
+	if err != nil {
+		return err
+	}
+	m.Codec = CompressionCodec(attribute & compressionCodecMask)
+	m.LogAppendTime = attribute&timestampTypeMask == timestampTypeMask
+
+	if m.Version == 1 {
+		if err := (Timestamp{&m.Timestamp}).decode(pd); err != nil {
+			return err
+		}
+	}
+
+	m.Key, err = pd.getBytes()
+	if err != nil {
+		return err
+	}
+
+	m.Value, err = pd.getBytes()
+	if err != nil {
+		return err
+	}
+
+	// Required for deep equal assertion during tests but might be useful
+	// for future metrics about the compression ratio in fetch requests
+	m.compressedSize = len(m.Value)
+
+	switch m.Codec {
+	case CompressionNone:
+		// nothing to do
+	default:
+		if m.Value == nil {
+			break
+		}
+
+		m.Value, err = decompress(m.Codec, m.Value)
+		if err != nil {
+			return err
+		}
+		if err := m.decodeSet(); err != nil {
+			return err
+		}
+	}
+
+	return pd.pop()
+}
+
+// decodes a message set from a previously encoded bulk-message
+func (m *Message) decodeSet() (err error) {
+	pd := realDecoder{raw: m.Value}
+	m.Set = &MessageSet{}
+	return m.Set.decode(&pd)
+}
diff --git a/vendor/github.com/Shopify/sarama/message_set.go b/vendor/github.com/Shopify/sarama/message_set.go
new file mode 100644
index 0000000..6523ec2
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/message_set.go
@@ -0,0 +1,111 @@
+package sarama
+
+type MessageBlock struct {
+	Offset int64
+	Msg    *Message
+}
+
+// Messages convenience helper which returns either all the
+// messages that are wrapped in this block
+func (msb *MessageBlock) Messages() []*MessageBlock {
+	if msb.Msg.Set != nil {
+		return msb.Msg.Set.Messages
+	}
+	return []*MessageBlock{msb}
+}
+
+func (msb *MessageBlock) encode(pe packetEncoder) error {
+	pe.putInt64(msb.Offset)
+	pe.push(&lengthField{})
+	err := msb.Msg.encode(pe)
+	if err != nil {
+		return err
+	}
+	return pe.pop()
+}
+
+func (msb *MessageBlock) decode(pd packetDecoder) (err error) {
+	if msb.Offset, err = pd.getInt64(); err != nil {
+		return err
+	}
+
+	lengthDecoder := acquireLengthField()
+	defer releaseLengthField(lengthDecoder)
+
+	if err = pd.push(lengthDecoder); err != nil {
+		return err
+	}
+
+	msb.Msg = new(Message)
+	if err = msb.Msg.decode(pd); err != nil {
+		return err
+	}
+
+	if err = pd.pop(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+type MessageSet struct {
+	PartialTrailingMessage bool // whether the set on the wire contained an incomplete trailing MessageBlock
+	OverflowMessage        bool // whether the set on the wire contained an overflow message
+	Messages               []*MessageBlock
+}
+
+func (ms *MessageSet) encode(pe packetEncoder) error {
+	for i := range ms.Messages {
+		err := ms.Messages[i].encode(pe)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (ms *MessageSet) decode(pd packetDecoder) (err error) {
+	ms.Messages = nil
+
+	for pd.remaining() > 0 {
+		magic, err := magicValue(pd)
+		if err != nil {
+			if err == ErrInsufficientData {
+				ms.PartialTrailingMessage = true
+				return nil
+			}
+			return err
+		}
+
+		if magic > 1 {
+			return nil
+		}
+
+		msb := new(MessageBlock)
+		err = msb.decode(pd)
+		switch err {
+		case nil:
+			ms.Messages = append(ms.Messages, msb)
+		case ErrInsufficientData:
+			// As an optimization the server is allowed to return a partial message at the
+			// end of the message set. Clients should handle this case. So we just ignore such things.
+			if msb.Offset == -1 {
+				// This is an overflow message caused by chunked down conversion
+				ms.OverflowMessage = true
+			} else {
+				ms.PartialTrailingMessage = true
+			}
+			return nil
+		default:
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (ms *MessageSet) addMessage(msg *Message) {
+	block := new(MessageBlock)
+	block.Msg = msg
+	ms.Messages = append(ms.Messages, block)
+}
diff --git a/vendor/github.com/Shopify/sarama/metadata_request.go b/vendor/github.com/Shopify/sarama/metadata_request.go
new file mode 100644
index 0000000..1b590d3
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/metadata_request.go
@@ -0,0 +1,81 @@
+package sarama
+
+type MetadataRequest struct {
+	Version                int16
+	Topics                 []string
+	AllowAutoTopicCreation bool
+}
+
+func (r *MetadataRequest) encode(pe packetEncoder) error {
+	if r.Version < 0 || r.Version > 5 {
+		return PacketEncodingError{"invalid or unsupported MetadataRequest version field"}
+	}
+	if r.Version == 0 || len(r.Topics) > 0 {
+		err := pe.putArrayLength(len(r.Topics))
+		if err != nil {
+			return err
+		}
+
+		for i := range r.Topics {
+			err = pe.putString(r.Topics[i])
+			if err != nil {
+				return err
+			}
+		}
+	} else {
+		pe.putInt32(-1)
+	}
+	if r.Version > 3 {
+		pe.putBool(r.AllowAutoTopicCreation)
+	}
+	return nil
+}
+
+func (r *MetadataRequest) decode(pd packetDecoder, version int16) error {
+	r.Version = version
+	size, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	if size > 0 {
+		r.Topics = make([]string, size)
+		for i := range r.Topics {
+			topic, err := pd.getString()
+			if err != nil {
+				return err
+			}
+			r.Topics[i] = topic
+		}
+	}
+	if r.Version > 3 {
+		autoCreation, err := pd.getBool()
+		if err != nil {
+			return err
+		}
+		r.AllowAutoTopicCreation = autoCreation
+	}
+	return nil
+}
+
+func (r *MetadataRequest) key() int16 {
+	return 3
+}
+
+func (r *MetadataRequest) version() int16 {
+	return r.Version
+}
+
+func (r *MetadataRequest) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_10_0_0
+	case 2:
+		return V0_10_1_0
+	case 3, 4:
+		return V0_11_0_0
+	case 5:
+		return V1_0_0_0
+	default:
+		return MinVersion
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/metadata_response.go b/vendor/github.com/Shopify/sarama/metadata_response.go
new file mode 100644
index 0000000..b2d532e
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/metadata_response.go
@@ -0,0 +1,322 @@
+package sarama
+
+type PartitionMetadata struct {
+	Err             KError
+	ID              int32
+	Leader          int32
+	Replicas        []int32
+	Isr             []int32
+	OfflineReplicas []int32
+}
+
+func (pm *PartitionMetadata) decode(pd packetDecoder, version int16) (err error) {
+	tmp, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	pm.Err = KError(tmp)
+
+	pm.ID, err = pd.getInt32()
+	if err != nil {
+		return err
+	}
+
+	pm.Leader, err = pd.getInt32()
+	if err != nil {
+		return err
+	}
+
+	pm.Replicas, err = pd.getInt32Array()
+	if err != nil {
+		return err
+	}
+
+	pm.Isr, err = pd.getInt32Array()
+	if err != nil {
+		return err
+	}
+
+	if version >= 5 {
+		pm.OfflineReplicas, err = pd.getInt32Array()
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (pm *PartitionMetadata) encode(pe packetEncoder, version int16) (err error) {
+	pe.putInt16(int16(pm.Err))
+	pe.putInt32(pm.ID)
+	pe.putInt32(pm.Leader)
+
+	err = pe.putInt32Array(pm.Replicas)
+	if err != nil {
+		return err
+	}
+
+	err = pe.putInt32Array(pm.Isr)
+	if err != nil {
+		return err
+	}
+
+	if version >= 5 {
+		err = pe.putInt32Array(pm.OfflineReplicas)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+type TopicMetadata struct {
+	Err        KError
+	Name       string
+	IsInternal bool // Only valid for Version >= 1
+	Partitions []*PartitionMetadata
+}
+
+func (tm *TopicMetadata) decode(pd packetDecoder, version int16) (err error) {
+	tmp, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	tm.Err = KError(tmp)
+
+	tm.Name, err = pd.getString()
+	if err != nil {
+		return err
+	}
+
+	if version >= 1 {
+		tm.IsInternal, err = pd.getBool()
+		if err != nil {
+			return err
+		}
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	tm.Partitions = make([]*PartitionMetadata, n)
+	for i := 0; i < n; i++ {
+		tm.Partitions[i] = new(PartitionMetadata)
+		err = tm.Partitions[i].decode(pd, version)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (tm *TopicMetadata) encode(pe packetEncoder, version int16) (err error) {
+	pe.putInt16(int16(tm.Err))
+
+	err = pe.putString(tm.Name)
+	if err != nil {
+		return err
+	}
+
+	if version >= 1 {
+		pe.putBool(tm.IsInternal)
+	}
+
+	err = pe.putArrayLength(len(tm.Partitions))
+	if err != nil {
+		return err
+	}
+
+	for _, pm := range tm.Partitions {
+		err = pm.encode(pe, version)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+type MetadataResponse struct {
+	Version        int16
+	ThrottleTimeMs int32
+	Brokers        []*Broker
+	ClusterID      *string
+	ControllerID   int32
+	Topics         []*TopicMetadata
+}
+
+func (r *MetadataResponse) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+
+	if version >= 3 {
+		r.ThrottleTimeMs, err = pd.getInt32()
+		if err != nil {
+			return err
+		}
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Brokers = make([]*Broker, n)
+	for i := 0; i < n; i++ {
+		r.Brokers[i] = new(Broker)
+		err = r.Brokers[i].decode(pd, version)
+		if err != nil {
+			return err
+		}
+	}
+
+	if version >= 2 {
+		r.ClusterID, err = pd.getNullableString()
+		if err != nil {
+			return err
+		}
+	}
+
+	if version >= 1 {
+		r.ControllerID, err = pd.getInt32()
+		if err != nil {
+			return err
+		}
+	} else {
+		r.ControllerID = -1
+	}
+
+	n, err = pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Topics = make([]*TopicMetadata, n)
+	for i := 0; i < n; i++ {
+		r.Topics[i] = new(TopicMetadata)
+		err = r.Topics[i].decode(pd, version)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *MetadataResponse) encode(pe packetEncoder) error {
+	if r.Version >= 3 {
+		pe.putInt32(r.ThrottleTimeMs)
+	}
+
+	err := pe.putArrayLength(len(r.Brokers))
+	if err != nil {
+		return err
+	}
+	for _, broker := range r.Brokers {
+		err = broker.encode(pe, r.Version)
+		if err != nil {
+			return err
+		}
+	}
+
+	if r.Version >= 2 {
+		err := pe.putNullableString(r.ClusterID)
+		if err != nil {
+			return err
+		}
+	}
+
+	if r.Version >= 1 {
+		pe.putInt32(r.ControllerID)
+	}
+
+	err = pe.putArrayLength(len(r.Topics))
+	if err != nil {
+		return err
+	}
+	for _, tm := range r.Topics {
+		err = tm.encode(pe, r.Version)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *MetadataResponse) key() int16 {
+	return 3
+}
+
+func (r *MetadataResponse) version() int16 {
+	return r.Version
+}
+
+func (r *MetadataResponse) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_10_0_0
+	case 2:
+		return V0_10_1_0
+	case 3, 4:
+		return V0_11_0_0
+	case 5:
+		return V1_0_0_0
+	default:
+		return MinVersion
+	}
+}
+
+// testing API
+
+func (r *MetadataResponse) AddBroker(addr string, id int32) {
+	r.Brokers = append(r.Brokers, &Broker{id: id, addr: addr})
+}
+
+func (r *MetadataResponse) AddTopic(topic string, err KError) *TopicMetadata {
+	var tmatch *TopicMetadata
+
+	for _, tm := range r.Topics {
+		if tm.Name == topic {
+			tmatch = tm
+			goto foundTopic
+		}
+	}
+
+	tmatch = new(TopicMetadata)
+	tmatch.Name = topic
+	r.Topics = append(r.Topics, tmatch)
+
+foundTopic:
+
+	tmatch.Err = err
+	return tmatch
+}
+
+func (r *MetadataResponse) AddTopicPartition(topic string, partition, brokerID int32, replicas, isr []int32, offline []int32, err KError) {
+	tmatch := r.AddTopic(topic, ErrNoError)
+	var pmatch *PartitionMetadata
+
+	for _, pm := range tmatch.Partitions {
+		if pm.ID == partition {
+			pmatch = pm
+			goto foundPartition
+		}
+	}
+
+	pmatch = new(PartitionMetadata)
+	pmatch.ID = partition
+	tmatch.Partitions = append(tmatch.Partitions, pmatch)
+
+foundPartition:
+
+	pmatch.Leader = brokerID
+	pmatch.Replicas = replicas
+	pmatch.Isr = isr
+	pmatch.OfflineReplicas = offline
+	pmatch.Err = err
+
+}
diff --git a/vendor/github.com/Shopify/sarama/metrics.go b/vendor/github.com/Shopify/sarama/metrics.go
new file mode 100644
index 0000000..90e5a87
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/metrics.go
@@ -0,0 +1,43 @@
+package sarama
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/rcrowley/go-metrics"
+)
+
+// Use exponentially decaying reservoir for sampling histograms with the same defaults as the Java library:
+// 1028 elements, which offers a 99.9% confidence level with a 5% margin of error assuming a normal distribution,
+// and an alpha factor of 0.015, which heavily biases the reservoir to the past 5 minutes of measurements.
+// See https://github.com/dropwizard/metrics/blob/v3.1.0/metrics-core/src/main/java/com/codahale/metrics/ExponentiallyDecayingReservoir.java#L38
+const (
+	metricsReservoirSize = 1028
+	metricsAlphaFactor   = 0.015
+)
+
+func getOrRegisterHistogram(name string, r metrics.Registry) metrics.Histogram {
+	return r.GetOrRegister(name, func() metrics.Histogram {
+		return metrics.NewHistogram(metrics.NewExpDecaySample(metricsReservoirSize, metricsAlphaFactor))
+	}).(metrics.Histogram)
+}
+
+func getMetricNameForBroker(name string, broker *Broker) string {
+	// Use broker id like the Java client as it does not contain '.' or ':' characters that
+	// can be interpreted as special character by monitoring tool (e.g. Graphite)
+	return fmt.Sprintf(name+"-for-broker-%d", broker.ID())
+}
+
+func getMetricNameForTopic(name string, topic string) string {
+	// Convert dot to _ since reporters like Graphite typically use dot to represent hierarchy
+	// cf. KAFKA-1902 and KAFKA-2337
+	return fmt.Sprintf(name+"-for-topic-%s", strings.Replace(topic, ".", "_", -1))
+}
+
+func getOrRegisterTopicMeter(name string, topic string, r metrics.Registry) metrics.Meter {
+	return metrics.GetOrRegisterMeter(getMetricNameForTopic(name, topic), r)
+}
+
+func getOrRegisterTopicHistogram(name string, topic string, r metrics.Registry) metrics.Histogram {
+	return getOrRegisterHistogram(getMetricNameForTopic(name, topic), r)
+}
diff --git a/vendor/github.com/Shopify/sarama/mockbroker.go b/vendor/github.com/Shopify/sarama/mockbroker.go
new file mode 100644
index 0000000..4ed46a6
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/mockbroker.go
@@ -0,0 +1,403 @@
+package sarama
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"net"
+	"reflect"
+	"strconv"
+	"sync"
+	"time"
+
+	"github.com/davecgh/go-spew/spew"
+)
+
+const (
+	expectationTimeout = 500 * time.Millisecond
+)
+
+type GSSApiHandlerFunc func([]byte) []byte
+
+type requestHandlerFunc func(req *request) (res encoder)
+
+// RequestNotifierFunc is invoked when a mock broker processes a request successfully
+// and will provides the number of bytes read and written.
+type RequestNotifierFunc func(bytesRead, bytesWritten int)
+
+// MockBroker is a mock Kafka broker that is used in unit tests. It is exposed
+// to facilitate testing of higher level or specialized consumers and producers
+// built on top of Sarama. Note that it does not 'mimic' the Kafka API protocol,
+// but rather provides a facility to do that. It takes care of the TCP
+// transport, request unmarshaling, response marshaling, and makes it the test
+// writer responsibility to program correct according to the Kafka API protocol
+// MockBroker behaviour.
+//
+// MockBroker is implemented as a TCP server listening on a kernel-selected
+// localhost port that can accept many connections. It reads Kafka requests
+// from that connection and returns responses programmed by the SetHandlerByMap
+// function. If a MockBroker receives a request that it has no programmed
+// response for, then it returns nothing and the request times out.
+//
+// A set of MockRequest builders to define mappings used by MockBroker is
+// provided by Sarama. But users can develop MockRequests of their own and use
+// them along with or instead of the standard ones.
+//
+// When running tests with MockBroker it is strongly recommended to specify
+// a timeout to `go test` so that if the broker hangs waiting for a response,
+// the test panics.
+//
+// It is not necessary to prefix message length or correlation ID to your
+// response bytes, the server does that automatically as a convenience.
+type MockBroker struct {
+	brokerID      int32
+	port          int32
+	closing       chan none
+	stopper       chan none
+	expectations  chan encoder
+	listener      net.Listener
+	t             TestReporter
+	latency       time.Duration
+	handler       requestHandlerFunc
+	notifier      RequestNotifierFunc
+	history       []RequestResponse
+	lock          sync.Mutex
+	gssApiHandler GSSApiHandlerFunc
+}
+
+// RequestResponse represents a Request/Response pair processed by MockBroker.
+type RequestResponse struct {
+	Request  protocolBody
+	Response encoder
+}
+
+// SetLatency makes broker pause for the specified period every time before
+// replying.
+func (b *MockBroker) SetLatency(latency time.Duration) {
+	b.latency = latency
+}
+
+// SetHandlerByMap defines mapping of Request types to MockResponses. When a
+// request is received by the broker, it looks up the request type in the map
+// and uses the found MockResponse instance to generate an appropriate reply.
+// If the request type is not found in the map then nothing is sent.
+func (b *MockBroker) SetHandlerByMap(handlerMap map[string]MockResponse) {
+	b.setHandler(func(req *request) (res encoder) {
+		reqTypeName := reflect.TypeOf(req.body).Elem().Name()
+		mockResponse := handlerMap[reqTypeName]
+		if mockResponse == nil {
+			return nil
+		}
+		return mockResponse.For(req.body)
+	})
+}
+
+// SetNotifier set a function that will get invoked whenever a request has been
+// processed successfully and will provide the number of bytes read and written
+func (b *MockBroker) SetNotifier(notifier RequestNotifierFunc) {
+	b.lock.Lock()
+	b.notifier = notifier
+	b.lock.Unlock()
+}
+
+// BrokerID returns broker ID assigned to the broker.
+func (b *MockBroker) BrokerID() int32 {
+	return b.brokerID
+}
+
+// History returns a slice of RequestResponse pairs in the order they were
+// processed by the broker. Note that in case of multiple connections to the
+// broker the order expected by a test can be different from the order recorded
+// in the history, unless some synchronization is implemented in the test.
+func (b *MockBroker) History() []RequestResponse {
+	b.lock.Lock()
+	history := make([]RequestResponse, len(b.history))
+	copy(history, b.history)
+	b.lock.Unlock()
+	return history
+}
+
+// Port returns the TCP port number the broker is listening for requests on.
+func (b *MockBroker) Port() int32 {
+	return b.port
+}
+
+// Addr returns the broker connection string in the form "<address>:<port>".
+func (b *MockBroker) Addr() string {
+	return b.listener.Addr().String()
+}
+
+// Close terminates the broker blocking until it stops internal goroutines and
+// releases all resources.
+func (b *MockBroker) Close() {
+	close(b.expectations)
+	if len(b.expectations) > 0 {
+		buf := bytes.NewBufferString(fmt.Sprintf("mockbroker/%d: not all expectations were satisfied! Still waiting on:\n", b.BrokerID()))
+		for e := range b.expectations {
+			_, _ = buf.WriteString(spew.Sdump(e))
+		}
+		b.t.Error(buf.String())
+	}
+	close(b.closing)
+	<-b.stopper
+}
+
+// setHandler sets the specified function as the request handler. Whenever
+// a mock broker reads a request from the wire it passes the request to the
+// function and sends back whatever the handler function returns.
+func (b *MockBroker) setHandler(handler requestHandlerFunc) {
+	b.lock.Lock()
+	b.handler = handler
+	b.lock.Unlock()
+}
+
+func (b *MockBroker) serverLoop() {
+	defer close(b.stopper)
+	var err error
+	var conn net.Conn
+
+	go func() {
+		<-b.closing
+		err := b.listener.Close()
+		if err != nil {
+			b.t.Error(err)
+		}
+	}()
+
+	wg := &sync.WaitGroup{}
+	i := 0
+	for conn, err = b.listener.Accept(); err == nil; conn, err = b.listener.Accept() {
+		wg.Add(1)
+		go b.handleRequests(conn, i, wg)
+		i++
+	}
+	wg.Wait()
+	Logger.Printf("*** mockbroker/%d: listener closed, err=%v", b.BrokerID(), err)
+}
+
+func (b *MockBroker) SetGSSAPIHandler(handler GSSApiHandlerFunc) {
+	b.gssApiHandler = handler
+}
+
+func (b *MockBroker) readToBytes(r io.Reader) ([]byte, error) {
+	var (
+		bytesRead   int
+		lengthBytes = make([]byte, 4)
+	)
+
+	if _, err := io.ReadFull(r, lengthBytes); err != nil {
+		return nil, err
+	}
+
+	bytesRead += len(lengthBytes)
+	length := int32(binary.BigEndian.Uint32(lengthBytes))
+
+	if length <= 4 || length > MaxRequestSize {
+		return nil, PacketDecodingError{fmt.Sprintf("message of length %d too large or too small", length)}
+	}
+
+	encodedReq := make([]byte, length)
+	if _, err := io.ReadFull(r, encodedReq); err != nil {
+		return nil, err
+	}
+
+	bytesRead += len(encodedReq)
+
+	fullBytes := append(lengthBytes, encodedReq...)
+
+	return fullBytes, nil
+}
+
+func (b *MockBroker) isGSSAPI(buffer []byte) bool {
+	return buffer[4] == 0x60 || bytes.Equal(buffer[4:6], []byte{0x05, 0x04})
+}
+
+func (b *MockBroker) handleRequests(conn net.Conn, idx int, wg *sync.WaitGroup) {
+	defer wg.Done()
+	defer func() {
+		_ = conn.Close()
+	}()
+	Logger.Printf("*** mockbroker/%d/%d: connection opened", b.BrokerID(), idx)
+	var err error
+
+	abort := make(chan none)
+	defer close(abort)
+	go func() {
+		select {
+		case <-b.closing:
+			_ = conn.Close()
+		case <-abort:
+		}
+	}()
+
+	resHeader := make([]byte, 8)
+	var bytesWritten int
+	var bytesRead int
+	for {
+
+		buffer, err := b.readToBytes(conn)
+		if err != nil {
+			Logger.Printf("*** mockbroker/%d/%d: invalid request: err=%+v, %+v", b.brokerID, idx, err, spew.Sdump(buffer))
+			b.serverError(err)
+			break
+		}
+
+		bytesWritten = 0
+		if !b.isGSSAPI(buffer) {
+
+			req, br, err := decodeRequest(bytes.NewReader(buffer))
+			bytesRead = br
+			if err != nil {
+				Logger.Printf("*** mockbroker/%d/%d: invalid request: err=%+v, %+v", b.brokerID, idx, err, spew.Sdump(req))
+				b.serverError(err)
+				break
+			}
+
+			if b.latency > 0 {
+				time.Sleep(b.latency)
+			}
+
+			b.lock.Lock()
+			res := b.handler(req)
+			b.history = append(b.history, RequestResponse{req.body, res})
+			b.lock.Unlock()
+
+			if res == nil {
+				Logger.Printf("*** mockbroker/%d/%d: ignored %v", b.brokerID, idx, spew.Sdump(req))
+				continue
+			}
+			Logger.Printf("*** mockbroker/%d/%d: served %v -> %v", b.brokerID, idx, req, res)
+
+			encodedRes, err := encode(res, nil)
+			if err != nil {
+				b.serverError(err)
+				break
+			}
+			if len(encodedRes) == 0 {
+				b.lock.Lock()
+				if b.notifier != nil {
+					b.notifier(bytesRead, 0)
+				}
+				b.lock.Unlock()
+				continue
+			}
+
+			binary.BigEndian.PutUint32(resHeader, uint32(len(encodedRes)+4))
+			binary.BigEndian.PutUint32(resHeader[4:], uint32(req.correlationID))
+			if _, err = conn.Write(resHeader); err != nil {
+				b.serverError(err)
+				break
+			}
+			if _, err = conn.Write(encodedRes); err != nil {
+				b.serverError(err)
+				break
+			}
+			bytesWritten = len(resHeader) + len(encodedRes)
+
+		} else {
+			// GSSAPI is not part of kafka protocol, but is supported for authentication proposes.
+			// Don't support history for this kind of request as is only used for test GSSAPI authentication mechanism
+			b.lock.Lock()
+			res := b.gssApiHandler(buffer)
+			b.lock.Unlock()
+			if res == nil {
+				Logger.Printf("*** mockbroker/%d/%d: ignored %v", b.brokerID, idx, spew.Sdump(buffer))
+				continue
+			}
+			if _, err = conn.Write(res); err != nil {
+				b.serverError(err)
+				break
+			}
+			bytesWritten = len(res)
+		}
+
+		b.lock.Lock()
+		if b.notifier != nil {
+			b.notifier(bytesRead, bytesWritten)
+		}
+		b.lock.Unlock()
+
+	}
+	Logger.Printf("*** mockbroker/%d/%d: connection closed, err=%v", b.BrokerID(), idx, err)
+}
+
+func (b *MockBroker) defaultRequestHandler(req *request) (res encoder) {
+	select {
+	case res, ok := <-b.expectations:
+		if !ok {
+			return nil
+		}
+		return res
+	case <-time.After(expectationTimeout):
+		return nil
+	}
+}
+
+func (b *MockBroker) serverError(err error) {
+	isConnectionClosedError := false
+	if _, ok := err.(*net.OpError); ok {
+		isConnectionClosedError = true
+	} else if err == io.EOF {
+		isConnectionClosedError = true
+	} else if err.Error() == "use of closed network connection" {
+		isConnectionClosedError = true
+	}
+
+	if isConnectionClosedError {
+		return
+	}
+
+	b.t.Errorf(err.Error())
+}
+
+// NewMockBroker launches a fake Kafka broker. It takes a TestReporter as provided by the
+// test framework and a channel of responses to use.  If an error occurs it is
+// simply logged to the TestReporter and the broker exits.
+func NewMockBroker(t TestReporter, brokerID int32) *MockBroker {
+	return NewMockBrokerAddr(t, brokerID, "localhost:0")
+}
+
+// NewMockBrokerAddr behaves like newMockBroker but listens on the address you give
+// it rather than just some ephemeral port.
+func NewMockBrokerAddr(t TestReporter, brokerID int32, addr string) *MockBroker {
+	listener, err := net.Listen("tcp", addr)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return NewMockBrokerListener(t, brokerID, listener)
+}
+
+// NewMockBrokerListener behaves like newMockBrokerAddr but accepts connections on the listener specified.
+func NewMockBrokerListener(t TestReporter, brokerID int32, listener net.Listener) *MockBroker {
+	var err error
+
+	broker := &MockBroker{
+		closing:      make(chan none),
+		stopper:      make(chan none),
+		t:            t,
+		brokerID:     brokerID,
+		expectations: make(chan encoder, 512),
+		listener:     listener,
+	}
+	broker.handler = broker.defaultRequestHandler
+
+	Logger.Printf("*** mockbroker/%d listening on %s\n", brokerID, broker.listener.Addr().String())
+	_, portStr, err := net.SplitHostPort(broker.listener.Addr().String())
+	if err != nil {
+		t.Fatal(err)
+	}
+	tmp, err := strconv.ParseInt(portStr, 10, 32)
+	if err != nil {
+		t.Fatal(err)
+	}
+	broker.port = int32(tmp)
+
+	go broker.serverLoop()
+
+	return broker
+}
+
+func (b *MockBroker) Returns(e encoder) {
+	b.expectations <- e
+}
diff --git a/vendor/github.com/Shopify/sarama/mockkerberos.go b/vendor/github.com/Shopify/sarama/mockkerberos.go
new file mode 100644
index 0000000..affeb2d
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/mockkerberos.go
@@ -0,0 +1,123 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"encoding/hex"
+	"gopkg.in/jcmturner/gokrb5.v7/credentials"
+	"gopkg.in/jcmturner/gokrb5.v7/gssapi"
+	"gopkg.in/jcmturner/gokrb5.v7/iana/keyusage"
+	"gopkg.in/jcmturner/gokrb5.v7/messages"
+	"gopkg.in/jcmturner/gokrb5.v7/types"
+)
+
+type KafkaGSSAPIHandler struct {
+	client         *MockKerberosClient
+	badResponse    bool
+	badKeyChecksum bool
+}
+
+func (h *KafkaGSSAPIHandler) MockKafkaGSSAPI(buffer []byte) []byte {
+	// Default payload used for verify
+	err := h.client.Login() // Mock client construct keys when login
+	if err != nil {
+		return nil
+	}
+	if h.badResponse { // Returns trash
+		return []byte{0x00, 0x00, 0x00, 0x01, 0xAD}
+	}
+
+	var pack = gssapi.WrapToken{
+		Flags:     KRB5_USER_AUTH,
+		EC:        12,
+		RRC:       0,
+		SndSeqNum: 3398292281,
+		Payload:   []byte{0x11, 0x00}, // 1100
+	}
+	// Compute checksum
+	if h.badKeyChecksum {
+		pack.CheckSum = []byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}
+	} else {
+		err = pack.SetCheckSum(h.client.ASRep.DecryptedEncPart.Key, keyusage.GSSAPI_ACCEPTOR_SEAL)
+		if err != nil {
+			return nil
+		}
+	}
+
+	packBytes, err := pack.Marshal()
+	if err != nil {
+		return nil
+	}
+	lenBytes := len(packBytes)
+	response := make([]byte, lenBytes+4)
+	copy(response[4:], packBytes)
+	binary.BigEndian.PutUint32(response, uint32(lenBytes))
+	return response
+}
+
+type MockKerberosClient struct {
+	asReqBytes  string
+	asRepBytes  string
+	ASRep       messages.ASRep
+	credentials *credentials.Credentials
+	mockError   error
+	errorStage  string
+}
+
+func (c *MockKerberosClient) Login() error {
+	if c.errorStage == "login" && c.mockError != nil {
+		return c.mockError
+	}
+	c.asRepBytes = "6b8202e9308202e5a003020105a10302010ba22b30293027a103020113a220041e301c301aa003020112a1131b114" +
+		"558414d504c452e434f4d636c69656e74a30d1b0b4558414d504c452e434f4da4133011a003020101a10a30081b06636c69656e7" +
+		"4a5820156618201523082014ea003020105a10d1b0b4558414d504c452e434f4da220301ea003020102a11730151b066b7262746" +
+		"7741b0b4558414d504c452e434f4da382011430820110a003020112a103020101a28201020481ffdb9891175d106818e61008c51" +
+		"d0b3462bca92f3bf9d4cfa82de4c4d7aff9994ec87c573e3a3d54dcb2bb79618c76f2bf4a3d006f90d5bdbd049bc18f48be39203" +
+		"549ca02acaf63f292b12404f9b74c34b83687119d8f56552ccc0c50ebee2a53bb114c1b4619bb1d5d31f0f49b4d40a08a9b4c046" +
+		"2e1398d0b648be1c0e50c552ad16e1d8d8e74263dd0bf0ec591e4797dfd40a9a1be4ae830d03a306e053fd7586fef84ffc5e4a83" +
+		"7c3122bf3e6a40fe87e84019f6283634461b955712b44a5f7386c278bff94ec2c2dc0403247e29c2450e853471ceababf9b8911f" +
+		"997f2e3010b046d2c49eb438afb0f4c210821e80d4ffa4c9521eb895dcd68610b3feaa682012c30820128a003020112a282011f0" +
+		"482011bce73cbce3f1dd17661c412005f0f2257c756fe8e98ff97e6ec24b7bab66e5fd3a3827aeeae4757af0c6e892948122d8b2" +
+		"03c8df48df0ef5d142d0e416d688f11daa0fcd63d96bdd431d02b8e951c664eeff286a2be62383d274a04016d5f0e141da58cb86" +
+		"331de64063062f4f885e8e9ce5b181ca2fdc67897c5995e0ae1ae0c171a64493ff7bd91bc6d89cd4fce1e2b3ea0a10e34b0d5eda" +
+		"aa38ee727b50c5632ed1d2f2b457908e616178d0d80b72af209fb8ac9dbaa1768fa45931392b36b6d8c12400f8ded2efaa0654d0" +
+		"da1db966e8b5aab4706c800f95d559664646041fdb38b411c62fc0fbe0d25083a28562b0e1c8df16e62e9d5626b0addee489835f" +
+		"eedb0f26c05baa596b69b17f47920aa64b29dc77cfcc97ba47885"
+	apRepBytes, err := hex.DecodeString(c.asRepBytes)
+	if err != nil {
+		return err
+	}
+	err = c.ASRep.Unmarshal(apRepBytes)
+	if err != nil {
+		return err
+	}
+	c.credentials = credentials.New("client", "EXAMPLE.COM").WithPassword("qwerty")
+	_, err = c.ASRep.DecryptEncPart(c.credentials)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c *MockKerberosClient) GetServiceTicket(spn string) (messages.Ticket, types.EncryptionKey, error) {
+	if c.errorStage == "service_ticket" && c.mockError != nil {
+		return messages.Ticket{}, types.EncryptionKey{}, c.mockError
+	}
+	return c.ASRep.Ticket, c.ASRep.DecryptedEncPart.Key, nil
+}
+
+func (c *MockKerberosClient) Domain() string {
+	return "EXAMPLE.COM"
+}
+func (c *MockKerberosClient) CName() types.PrincipalName {
+	var p = types.PrincipalName{
+		NameType: KRB5_USER_AUTH,
+		NameString: []string{
+			"kafka",
+			"kafka",
+		},
+	}
+	return p
+}
+func (c *MockKerberosClient) Destroy() {
+	// Do nothing.
+}
diff --git a/vendor/github.com/Shopify/sarama/mockresponses.go b/vendor/github.com/Shopify/sarama/mockresponses.go
new file mode 100644
index 0000000..7dcc93e
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/mockresponses.go
@@ -0,0 +1,941 @@
+package sarama
+
+import (
+	"fmt"
+	"strings"
+)
+
+// TestReporter has methods matching go's testing.T to avoid importing
+// `testing` in the main part of the library.
+type TestReporter interface {
+	Error(...interface{})
+	Errorf(string, ...interface{})
+	Fatal(...interface{})
+	Fatalf(string, ...interface{})
+}
+
+// MockResponse is a response builder interface it defines one method that
+// allows generating a response based on a request body. MockResponses are used
+// to program behavior of MockBroker in tests.
+type MockResponse interface {
+	For(reqBody versionedDecoder) (res encoder)
+}
+
+// MockWrapper is a mock response builder that returns a particular concrete
+// response regardless of the actual request passed to the `For` method.
+type MockWrapper struct {
+	res encoder
+}
+
+func (mw *MockWrapper) For(reqBody versionedDecoder) (res encoder) {
+	return mw.res
+}
+
+func NewMockWrapper(res encoder) *MockWrapper {
+	return &MockWrapper{res: res}
+}
+
+// MockSequence is a mock response builder that is created from a sequence of
+// concrete responses. Every time when a `MockBroker` calls its `For` method
+// the next response from the sequence is returned. When the end of the
+// sequence is reached the last element from the sequence is returned.
+type MockSequence struct {
+	responses []MockResponse
+}
+
+func NewMockSequence(responses ...interface{}) *MockSequence {
+	ms := &MockSequence{}
+	ms.responses = make([]MockResponse, len(responses))
+	for i, res := range responses {
+		switch res := res.(type) {
+		case MockResponse:
+			ms.responses[i] = res
+		case encoder:
+			ms.responses[i] = NewMockWrapper(res)
+		default:
+			panic(fmt.Sprintf("Unexpected response type: %T", res))
+		}
+	}
+	return ms
+}
+
+func (mc *MockSequence) For(reqBody versionedDecoder) (res encoder) {
+	res = mc.responses[0].For(reqBody)
+	if len(mc.responses) > 1 {
+		mc.responses = mc.responses[1:]
+	}
+	return res
+}
+
+type MockListGroupsResponse struct {
+	groups map[string]string
+	t      TestReporter
+}
+
+func NewMockListGroupsResponse(t TestReporter) *MockListGroupsResponse {
+	return &MockListGroupsResponse{
+		groups: make(map[string]string),
+		t:      t,
+	}
+}
+
+func (m *MockListGroupsResponse) For(reqBody versionedDecoder) encoder {
+	request := reqBody.(*ListGroupsRequest)
+	_ = request
+	response := &ListGroupsResponse{
+		Groups: m.groups,
+	}
+	return response
+}
+
+func (m *MockListGroupsResponse) AddGroup(groupID, protocolType string) *MockListGroupsResponse {
+	m.groups[groupID] = protocolType
+	return m
+}
+
+type MockDescribeGroupsResponse struct {
+	groups map[string]*GroupDescription
+	t      TestReporter
+}
+
+func NewMockDescribeGroupsResponse(t TestReporter) *MockDescribeGroupsResponse {
+	return &MockDescribeGroupsResponse{
+		t:      t,
+		groups: make(map[string]*GroupDescription),
+	}
+}
+
+func (m *MockDescribeGroupsResponse) AddGroupDescription(groupID string, description *GroupDescription) *MockDescribeGroupsResponse {
+	m.groups[groupID] = description
+	return m
+}
+
+func (m *MockDescribeGroupsResponse) For(reqBody versionedDecoder) encoder {
+	request := reqBody.(*DescribeGroupsRequest)
+
+	response := &DescribeGroupsResponse{}
+	for _, requestedGroup := range request.Groups {
+		if group, ok := m.groups[requestedGroup]; ok {
+			response.Groups = append(response.Groups, group)
+		} else {
+			// Mimic real kafka - if a group doesn't exist, return
+			// an entry with state "Dead"
+			response.Groups = append(response.Groups, &GroupDescription{
+				GroupId: requestedGroup,
+				State:   "Dead",
+			})
+		}
+	}
+
+	return response
+}
+
+// MockMetadataResponse is a `MetadataResponse` builder.
+type MockMetadataResponse struct {
+	controllerID int32
+	leaders      map[string]map[int32]int32
+	brokers      map[string]int32
+	t            TestReporter
+}
+
+func NewMockMetadataResponse(t TestReporter) *MockMetadataResponse {
+	return &MockMetadataResponse{
+		leaders: make(map[string]map[int32]int32),
+		brokers: make(map[string]int32),
+		t:       t,
+	}
+}
+
+func (mmr *MockMetadataResponse) SetLeader(topic string, partition, brokerID int32) *MockMetadataResponse {
+	partitions := mmr.leaders[topic]
+	if partitions == nil {
+		partitions = make(map[int32]int32)
+		mmr.leaders[topic] = partitions
+	}
+	partitions[partition] = brokerID
+	return mmr
+}
+
+func (mmr *MockMetadataResponse) SetBroker(addr string, brokerID int32) *MockMetadataResponse {
+	mmr.brokers[addr] = brokerID
+	return mmr
+}
+
+func (mmr *MockMetadataResponse) SetController(brokerID int32) *MockMetadataResponse {
+	mmr.controllerID = brokerID
+	return mmr
+}
+
+func (mmr *MockMetadataResponse) For(reqBody versionedDecoder) encoder {
+	metadataRequest := reqBody.(*MetadataRequest)
+	metadataResponse := &MetadataResponse{
+		Version:      metadataRequest.version(),
+		ControllerID: mmr.controllerID,
+	}
+	for addr, brokerID := range mmr.brokers {
+		metadataResponse.AddBroker(addr, brokerID)
+	}
+
+	// Generate set of replicas
+	replicas := []int32{}
+	offlineReplicas := []int32{}
+	for _, brokerID := range mmr.brokers {
+		replicas = append(replicas, brokerID)
+	}
+
+	if len(metadataRequest.Topics) == 0 {
+		for topic, partitions := range mmr.leaders {
+			for partition, brokerID := range partitions {
+				metadataResponse.AddTopicPartition(topic, partition, brokerID, replicas, replicas, offlineReplicas, ErrNoError)
+			}
+		}
+		return metadataResponse
+	}
+	for _, topic := range metadataRequest.Topics {
+		for partition, brokerID := range mmr.leaders[topic] {
+			metadataResponse.AddTopicPartition(topic, partition, brokerID, replicas, replicas, offlineReplicas, ErrNoError)
+		}
+	}
+	return metadataResponse
+}
+
+// MockOffsetResponse is an `OffsetResponse` builder.
+type MockOffsetResponse struct {
+	offsets map[string]map[int32]map[int64]int64
+	t       TestReporter
+	version int16
+}
+
+func NewMockOffsetResponse(t TestReporter) *MockOffsetResponse {
+	return &MockOffsetResponse{
+		offsets: make(map[string]map[int32]map[int64]int64),
+		t:       t,
+	}
+}
+
+func (mor *MockOffsetResponse) SetVersion(version int16) *MockOffsetResponse {
+	mor.version = version
+	return mor
+}
+
+func (mor *MockOffsetResponse) SetOffset(topic string, partition int32, time, offset int64) *MockOffsetResponse {
+	partitions := mor.offsets[topic]
+	if partitions == nil {
+		partitions = make(map[int32]map[int64]int64)
+		mor.offsets[topic] = partitions
+	}
+	times := partitions[partition]
+	if times == nil {
+		times = make(map[int64]int64)
+		partitions[partition] = times
+	}
+	times[time] = offset
+	return mor
+}
+
+func (mor *MockOffsetResponse) For(reqBody versionedDecoder) encoder {
+	offsetRequest := reqBody.(*OffsetRequest)
+	offsetResponse := &OffsetResponse{Version: mor.version}
+	for topic, partitions := range offsetRequest.blocks {
+		for partition, block := range partitions {
+			offset := mor.getOffset(topic, partition, block.time)
+			offsetResponse.AddTopicPartition(topic, partition, offset)
+		}
+	}
+	return offsetResponse
+}
+
+func (mor *MockOffsetResponse) getOffset(topic string, partition int32, time int64) int64 {
+	partitions := mor.offsets[topic]
+	if partitions == nil {
+		mor.t.Errorf("missing topic: %s", topic)
+	}
+	times := partitions[partition]
+	if times == nil {
+		mor.t.Errorf("missing partition: %d", partition)
+	}
+	offset, ok := times[time]
+	if !ok {
+		mor.t.Errorf("missing time: %d", time)
+	}
+	return offset
+}
+
+// MockFetchResponse is a `FetchResponse` builder.
+type MockFetchResponse struct {
+	messages       map[string]map[int32]map[int64]Encoder
+	highWaterMarks map[string]map[int32]int64
+	t              TestReporter
+	batchSize      int
+	version        int16
+}
+
+func NewMockFetchResponse(t TestReporter, batchSize int) *MockFetchResponse {
+	return &MockFetchResponse{
+		messages:       make(map[string]map[int32]map[int64]Encoder),
+		highWaterMarks: make(map[string]map[int32]int64),
+		t:              t,
+		batchSize:      batchSize,
+	}
+}
+
+func (mfr *MockFetchResponse) SetVersion(version int16) *MockFetchResponse {
+	mfr.version = version
+	return mfr
+}
+
+func (mfr *MockFetchResponse) SetMessage(topic string, partition int32, offset int64, msg Encoder) *MockFetchResponse {
+	partitions := mfr.messages[topic]
+	if partitions == nil {
+		partitions = make(map[int32]map[int64]Encoder)
+		mfr.messages[topic] = partitions
+	}
+	messages := partitions[partition]
+	if messages == nil {
+		messages = make(map[int64]Encoder)
+		partitions[partition] = messages
+	}
+	messages[offset] = msg
+	return mfr
+}
+
+func (mfr *MockFetchResponse) SetHighWaterMark(topic string, partition int32, offset int64) *MockFetchResponse {
+	partitions := mfr.highWaterMarks[topic]
+	if partitions == nil {
+		partitions = make(map[int32]int64)
+		mfr.highWaterMarks[topic] = partitions
+	}
+	partitions[partition] = offset
+	return mfr
+}
+
+func (mfr *MockFetchResponse) For(reqBody versionedDecoder) encoder {
+	fetchRequest := reqBody.(*FetchRequest)
+	res := &FetchResponse{
+		Version: mfr.version,
+	}
+	for topic, partitions := range fetchRequest.blocks {
+		for partition, block := range partitions {
+			initialOffset := block.fetchOffset
+			offset := initialOffset
+			maxOffset := initialOffset + int64(mfr.getMessageCount(topic, partition))
+			for i := 0; i < mfr.batchSize && offset < maxOffset; {
+				msg := mfr.getMessage(topic, partition, offset)
+				if msg != nil {
+					res.AddMessage(topic, partition, nil, msg, offset)
+					i++
+				}
+				offset++
+			}
+			fb := res.GetBlock(topic, partition)
+			if fb == nil {
+				res.AddError(topic, partition, ErrNoError)
+				fb = res.GetBlock(topic, partition)
+			}
+			fb.HighWaterMarkOffset = mfr.getHighWaterMark(topic, partition)
+		}
+	}
+	return res
+}
+
+func (mfr *MockFetchResponse) getMessage(topic string, partition int32, offset int64) Encoder {
+	partitions := mfr.messages[topic]
+	if partitions == nil {
+		return nil
+	}
+	messages := partitions[partition]
+	if messages == nil {
+		return nil
+	}
+	return messages[offset]
+}
+
+func (mfr *MockFetchResponse) getMessageCount(topic string, partition int32) int {
+	partitions := mfr.messages[topic]
+	if partitions == nil {
+		return 0
+	}
+	messages := partitions[partition]
+	if messages == nil {
+		return 0
+	}
+	return len(messages)
+}
+
+func (mfr *MockFetchResponse) getHighWaterMark(topic string, partition int32) int64 {
+	partitions := mfr.highWaterMarks[topic]
+	if partitions == nil {
+		return 0
+	}
+	return partitions[partition]
+}
+
+// MockConsumerMetadataResponse is a `ConsumerMetadataResponse` builder.
+type MockConsumerMetadataResponse struct {
+	coordinators map[string]interface{}
+	t            TestReporter
+}
+
+func NewMockConsumerMetadataResponse(t TestReporter) *MockConsumerMetadataResponse {
+	return &MockConsumerMetadataResponse{
+		coordinators: make(map[string]interface{}),
+		t:            t,
+	}
+}
+
+func (mr *MockConsumerMetadataResponse) SetCoordinator(group string, broker *MockBroker) *MockConsumerMetadataResponse {
+	mr.coordinators[group] = broker
+	return mr
+}
+
+func (mr *MockConsumerMetadataResponse) SetError(group string, kerror KError) *MockConsumerMetadataResponse {
+	mr.coordinators[group] = kerror
+	return mr
+}
+
+func (mr *MockConsumerMetadataResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*ConsumerMetadataRequest)
+	group := req.ConsumerGroup
+	res := &ConsumerMetadataResponse{}
+	v := mr.coordinators[group]
+	switch v := v.(type) {
+	case *MockBroker:
+		res.Coordinator = &Broker{id: v.BrokerID(), addr: v.Addr()}
+	case KError:
+		res.Err = v
+	}
+	return res
+}
+
+// MockFindCoordinatorResponse is a `FindCoordinatorResponse` builder.
+type MockFindCoordinatorResponse struct {
+	groupCoordinators map[string]interface{}
+	transCoordinators map[string]interface{}
+	t                 TestReporter
+}
+
+func NewMockFindCoordinatorResponse(t TestReporter) *MockFindCoordinatorResponse {
+	return &MockFindCoordinatorResponse{
+		groupCoordinators: make(map[string]interface{}),
+		transCoordinators: make(map[string]interface{}),
+		t:                 t,
+	}
+}
+
+func (mr *MockFindCoordinatorResponse) SetCoordinator(coordinatorType CoordinatorType, group string, broker *MockBroker) *MockFindCoordinatorResponse {
+	switch coordinatorType {
+	case CoordinatorGroup:
+		mr.groupCoordinators[group] = broker
+	case CoordinatorTransaction:
+		mr.transCoordinators[group] = broker
+	}
+	return mr
+}
+
+func (mr *MockFindCoordinatorResponse) SetError(coordinatorType CoordinatorType, group string, kerror KError) *MockFindCoordinatorResponse {
+	switch coordinatorType {
+	case CoordinatorGroup:
+		mr.groupCoordinators[group] = kerror
+	case CoordinatorTransaction:
+		mr.transCoordinators[group] = kerror
+	}
+	return mr
+}
+
+func (mr *MockFindCoordinatorResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*FindCoordinatorRequest)
+	res := &FindCoordinatorResponse{}
+	var v interface{}
+	switch req.CoordinatorType {
+	case CoordinatorGroup:
+		v = mr.groupCoordinators[req.CoordinatorKey]
+	case CoordinatorTransaction:
+		v = mr.transCoordinators[req.CoordinatorKey]
+	}
+	switch v := v.(type) {
+	case *MockBroker:
+		res.Coordinator = &Broker{id: v.BrokerID(), addr: v.Addr()}
+	case KError:
+		res.Err = v
+	}
+	return res
+}
+
+// MockOffsetCommitResponse is a `OffsetCommitResponse` builder.
+type MockOffsetCommitResponse struct {
+	errors map[string]map[string]map[int32]KError
+	t      TestReporter
+}
+
+func NewMockOffsetCommitResponse(t TestReporter) *MockOffsetCommitResponse {
+	return &MockOffsetCommitResponse{t: t}
+}
+
+func (mr *MockOffsetCommitResponse) SetError(group, topic string, partition int32, kerror KError) *MockOffsetCommitResponse {
+	if mr.errors == nil {
+		mr.errors = make(map[string]map[string]map[int32]KError)
+	}
+	topics := mr.errors[group]
+	if topics == nil {
+		topics = make(map[string]map[int32]KError)
+		mr.errors[group] = topics
+	}
+	partitions := topics[topic]
+	if partitions == nil {
+		partitions = make(map[int32]KError)
+		topics[topic] = partitions
+	}
+	partitions[partition] = kerror
+	return mr
+}
+
+func (mr *MockOffsetCommitResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*OffsetCommitRequest)
+	group := req.ConsumerGroup
+	res := &OffsetCommitResponse{}
+	for topic, partitions := range req.blocks {
+		for partition := range partitions {
+			res.AddError(topic, partition, mr.getError(group, topic, partition))
+		}
+	}
+	return res
+}
+
+func (mr *MockOffsetCommitResponse) getError(group, topic string, partition int32) KError {
+	topics := mr.errors[group]
+	if topics == nil {
+		return ErrNoError
+	}
+	partitions := topics[topic]
+	if partitions == nil {
+		return ErrNoError
+	}
+	kerror, ok := partitions[partition]
+	if !ok {
+		return ErrNoError
+	}
+	return kerror
+}
+
+// MockProduceResponse is a `ProduceResponse` builder.
+type MockProduceResponse struct {
+	version int16
+	errors  map[string]map[int32]KError
+	t       TestReporter
+}
+
+func NewMockProduceResponse(t TestReporter) *MockProduceResponse {
+	return &MockProduceResponse{t: t}
+}
+
+func (mr *MockProduceResponse) SetVersion(version int16) *MockProduceResponse {
+	mr.version = version
+	return mr
+}
+
+func (mr *MockProduceResponse) SetError(topic string, partition int32, kerror KError) *MockProduceResponse {
+	if mr.errors == nil {
+		mr.errors = make(map[string]map[int32]KError)
+	}
+	partitions := mr.errors[topic]
+	if partitions == nil {
+		partitions = make(map[int32]KError)
+		mr.errors[topic] = partitions
+	}
+	partitions[partition] = kerror
+	return mr
+}
+
+func (mr *MockProduceResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*ProduceRequest)
+	res := &ProduceResponse{
+		Version: mr.version,
+	}
+	for topic, partitions := range req.records {
+		for partition := range partitions {
+			res.AddTopicPartition(topic, partition, mr.getError(topic, partition))
+		}
+	}
+	return res
+}
+
+func (mr *MockProduceResponse) getError(topic string, partition int32) KError {
+	partitions := mr.errors[topic]
+	if partitions == nil {
+		return ErrNoError
+	}
+	kerror, ok := partitions[partition]
+	if !ok {
+		return ErrNoError
+	}
+	return kerror
+}
+
+// MockOffsetFetchResponse is a `OffsetFetchResponse` builder.
+type MockOffsetFetchResponse struct {
+	offsets map[string]map[string]map[int32]*OffsetFetchResponseBlock
+	error   KError
+	t       TestReporter
+}
+
+func NewMockOffsetFetchResponse(t TestReporter) *MockOffsetFetchResponse {
+	return &MockOffsetFetchResponse{t: t}
+}
+
+func (mr *MockOffsetFetchResponse) SetOffset(group, topic string, partition int32, offset int64, metadata string, kerror KError) *MockOffsetFetchResponse {
+	if mr.offsets == nil {
+		mr.offsets = make(map[string]map[string]map[int32]*OffsetFetchResponseBlock)
+	}
+	topics := mr.offsets[group]
+	if topics == nil {
+		topics = make(map[string]map[int32]*OffsetFetchResponseBlock)
+		mr.offsets[group] = topics
+	}
+	partitions := topics[topic]
+	if partitions == nil {
+		partitions = make(map[int32]*OffsetFetchResponseBlock)
+		topics[topic] = partitions
+	}
+	partitions[partition] = &OffsetFetchResponseBlock{offset, 0, metadata, kerror}
+	return mr
+}
+
+func (mr *MockOffsetFetchResponse) SetError(kerror KError) *MockOffsetFetchResponse {
+	mr.error = kerror
+	return mr
+}
+
+func (mr *MockOffsetFetchResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*OffsetFetchRequest)
+	group := req.ConsumerGroup
+	res := &OffsetFetchResponse{Version: req.Version}
+
+	for topic, partitions := range mr.offsets[group] {
+		for partition, block := range partitions {
+			res.AddBlock(topic, partition, block)
+		}
+	}
+
+	if res.Version >= 2 {
+		res.Err = mr.error
+	}
+	return res
+}
+
+type MockCreateTopicsResponse struct {
+	t TestReporter
+}
+
+func NewMockCreateTopicsResponse(t TestReporter) *MockCreateTopicsResponse {
+	return &MockCreateTopicsResponse{t: t}
+}
+
+func (mr *MockCreateTopicsResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*CreateTopicsRequest)
+	res := &CreateTopicsResponse{
+		Version: req.Version,
+	}
+	res.TopicErrors = make(map[string]*TopicError)
+
+	for topic := range req.TopicDetails {
+		if res.Version >= 1 && strings.HasPrefix(topic, "_") {
+			msg := "insufficient permissions to create topic with reserved prefix"
+			res.TopicErrors[topic] = &TopicError{
+				Err:    ErrTopicAuthorizationFailed,
+				ErrMsg: &msg,
+			}
+			continue
+		}
+		res.TopicErrors[topic] = &TopicError{Err: ErrNoError}
+	}
+	return res
+}
+
+type MockDeleteTopicsResponse struct {
+	t TestReporter
+}
+
+func NewMockDeleteTopicsResponse(t TestReporter) *MockDeleteTopicsResponse {
+	return &MockDeleteTopicsResponse{t: t}
+}
+
+func (mr *MockDeleteTopicsResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*DeleteTopicsRequest)
+	res := &DeleteTopicsResponse{}
+	res.TopicErrorCodes = make(map[string]KError)
+
+	for _, topic := range req.Topics {
+		res.TopicErrorCodes[topic] = ErrNoError
+	}
+	res.Version = int16(req.Version)
+	return res
+}
+
+type MockCreatePartitionsResponse struct {
+	t TestReporter
+}
+
+func NewMockCreatePartitionsResponse(t TestReporter) *MockCreatePartitionsResponse {
+	return &MockCreatePartitionsResponse{t: t}
+}
+
+func (mr *MockCreatePartitionsResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*CreatePartitionsRequest)
+	res := &CreatePartitionsResponse{}
+	res.TopicPartitionErrors = make(map[string]*TopicPartitionError)
+
+	for topic := range req.TopicPartitions {
+		if strings.HasPrefix(topic, "_") {
+			msg := "insufficient permissions to create partition on topic with reserved prefix"
+			res.TopicPartitionErrors[topic] = &TopicPartitionError{
+				Err:    ErrTopicAuthorizationFailed,
+				ErrMsg: &msg,
+			}
+			continue
+		}
+		res.TopicPartitionErrors[topic] = &TopicPartitionError{Err: ErrNoError}
+	}
+	return res
+}
+
+type MockDeleteRecordsResponse struct {
+	t TestReporter
+}
+
+func NewMockDeleteRecordsResponse(t TestReporter) *MockDeleteRecordsResponse {
+	return &MockDeleteRecordsResponse{t: t}
+}
+
+func (mr *MockDeleteRecordsResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*DeleteRecordsRequest)
+	res := &DeleteRecordsResponse{}
+	res.Topics = make(map[string]*DeleteRecordsResponseTopic)
+
+	for topic, deleteRecordRequestTopic := range req.Topics {
+		partitions := make(map[int32]*DeleteRecordsResponsePartition)
+		for partition := range deleteRecordRequestTopic.PartitionOffsets {
+			partitions[partition] = &DeleteRecordsResponsePartition{Err: ErrNoError}
+		}
+		res.Topics[topic] = &DeleteRecordsResponseTopic{Partitions: partitions}
+	}
+	return res
+}
+
+type MockDescribeConfigsResponse struct {
+	t TestReporter
+}
+
+func NewMockDescribeConfigsResponse(t TestReporter) *MockDescribeConfigsResponse {
+	return &MockDescribeConfigsResponse{t: t}
+}
+
+func (mr *MockDescribeConfigsResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*DescribeConfigsRequest)
+	res := &DescribeConfigsResponse{}
+
+	for _, r := range req.Resources {
+		var configEntries []*ConfigEntry
+		switch r.Type {
+		case TopicResource:
+			configEntries = append(configEntries,
+				&ConfigEntry{Name: "max.message.bytes",
+					Value:     "1000000",
+					ReadOnly:  false,
+					Default:   true,
+					Sensitive: false,
+				}, &ConfigEntry{Name: "retention.ms",
+					Value:     "5000",
+					ReadOnly:  false,
+					Default:   false,
+					Sensitive: false,
+				}, &ConfigEntry{Name: "password",
+					Value:     "12345",
+					ReadOnly:  false,
+					Default:   false,
+					Sensitive: true,
+				})
+			res.Resources = append(res.Resources, &ResourceResponse{
+				Name:    r.Name,
+				Configs: configEntries,
+			})
+		}
+	}
+	return res
+}
+
+type MockAlterConfigsResponse struct {
+	t TestReporter
+}
+
+func NewMockAlterConfigsResponse(t TestReporter) *MockAlterConfigsResponse {
+	return &MockAlterConfigsResponse{t: t}
+}
+
+func (mr *MockAlterConfigsResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*AlterConfigsRequest)
+	res := &AlterConfigsResponse{}
+
+	for _, r := range req.Resources {
+		res.Resources = append(res.Resources, &AlterConfigsResourceResponse{Name: r.Name,
+			Type:     TopicResource,
+			ErrorMsg: "",
+		})
+	}
+	return res
+}
+
+type MockCreateAclsResponse struct {
+	t TestReporter
+}
+
+func NewMockCreateAclsResponse(t TestReporter) *MockCreateAclsResponse {
+	return &MockCreateAclsResponse{t: t}
+}
+
+func (mr *MockCreateAclsResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*CreateAclsRequest)
+	res := &CreateAclsResponse{}
+
+	for range req.AclCreations {
+		res.AclCreationResponses = append(res.AclCreationResponses, &AclCreationResponse{Err: ErrNoError})
+	}
+	return res
+}
+
+type MockListAclsResponse struct {
+	t TestReporter
+}
+
+func NewMockListAclsResponse(t TestReporter) *MockListAclsResponse {
+	return &MockListAclsResponse{t: t}
+}
+
+func (mr *MockListAclsResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*DescribeAclsRequest)
+	res := &DescribeAclsResponse{}
+	res.Err = ErrNoError
+	acl := &ResourceAcls{}
+	if req.ResourceName != nil {
+		acl.Resource.ResourceName = *req.ResourceName
+	}
+	acl.Resource.ResourcePatternType = req.ResourcePatternTypeFilter
+	acl.Resource.ResourceType = req.ResourceType
+
+	host := "*"
+	if req.Host != nil {
+		host = *req.Host
+	}
+
+	principal := "User:test"
+	if req.Principal != nil {
+		principal = *req.Principal
+	}
+
+	permissionType := req.PermissionType
+	if permissionType == AclPermissionAny {
+		permissionType = AclPermissionAllow
+	}
+
+	acl.Acls = append(acl.Acls, &Acl{Operation: req.Operation, PermissionType: permissionType, Host: host, Principal: principal})
+	res.ResourceAcls = append(res.ResourceAcls, acl)
+	res.Version = int16(req.Version)
+	return res
+}
+
+type MockSaslAuthenticateResponse struct {
+	t             TestReporter
+	kerror        KError
+	saslAuthBytes []byte
+}
+
+func NewMockSaslAuthenticateResponse(t TestReporter) *MockSaslAuthenticateResponse {
+	return &MockSaslAuthenticateResponse{t: t}
+}
+
+func (msar *MockSaslAuthenticateResponse) For(reqBody versionedDecoder) encoder {
+	res := &SaslAuthenticateResponse{}
+	res.Err = msar.kerror
+	res.SaslAuthBytes = msar.saslAuthBytes
+	return res
+}
+
+func (msar *MockSaslAuthenticateResponse) SetError(kerror KError) *MockSaslAuthenticateResponse {
+	msar.kerror = kerror
+	return msar
+}
+
+func (msar *MockSaslAuthenticateResponse) SetAuthBytes(saslAuthBytes []byte) *MockSaslAuthenticateResponse {
+	msar.saslAuthBytes = saslAuthBytes
+	return msar
+}
+
+type MockDeleteAclsResponse struct {
+	t TestReporter
+}
+
+type MockSaslHandshakeResponse struct {
+	enabledMechanisms []string
+	kerror            KError
+	t                 TestReporter
+}
+
+func NewMockSaslHandshakeResponse(t TestReporter) *MockSaslHandshakeResponse {
+	return &MockSaslHandshakeResponse{t: t}
+}
+
+func (mshr *MockSaslHandshakeResponse) For(reqBody versionedDecoder) encoder {
+	res := &SaslHandshakeResponse{}
+	res.Err = mshr.kerror
+	res.EnabledMechanisms = mshr.enabledMechanisms
+	return res
+}
+
+func (mshr *MockSaslHandshakeResponse) SetError(kerror KError) *MockSaslHandshakeResponse {
+	mshr.kerror = kerror
+	return mshr
+}
+
+func (mshr *MockSaslHandshakeResponse) SetEnabledMechanisms(enabledMechanisms []string) *MockSaslHandshakeResponse {
+	mshr.enabledMechanisms = enabledMechanisms
+	return mshr
+}
+
+func NewMockDeleteAclsResponse(t TestReporter) *MockDeleteAclsResponse {
+	return &MockDeleteAclsResponse{t: t}
+}
+
+func (mr *MockDeleteAclsResponse) For(reqBody versionedDecoder) encoder {
+	req := reqBody.(*DeleteAclsRequest)
+	res := &DeleteAclsResponse{}
+
+	for range req.Filters {
+		response := &FilterResponse{Err: ErrNoError}
+		response.MatchingAcls = append(response.MatchingAcls, &MatchingAcl{Err: ErrNoError})
+		res.FilterResponses = append(res.FilterResponses, response)
+	}
+	res.Version = int16(req.Version)
+	return res
+}
+
+type MockDeleteGroupsResponse struct {
+	deletedGroups []string
+}
+
+func NewMockDeleteGroupsRequest(t TestReporter) *MockDeleteGroupsResponse {
+	return &MockDeleteGroupsResponse{}
+}
+
+func (m *MockDeleteGroupsResponse) SetDeletedGroups(groups []string) *MockDeleteGroupsResponse {
+	m.deletedGroups = groups
+	return m
+}
+
+func (m *MockDeleteGroupsResponse) For(reqBody versionedDecoder) encoder {
+	resp := &DeleteGroupsResponse{
+		GroupErrorCodes: map[string]KError{},
+	}
+	for _, group := range m.deletedGroups {
+		resp.GroupErrorCodes[group] = ErrNoError
+	}
+	return resp
+}
diff --git a/vendor/github.com/Shopify/sarama/offset_commit_request.go b/vendor/github.com/Shopify/sarama/offset_commit_request.go
new file mode 100644
index 0000000..5732ed9
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/offset_commit_request.go
@@ -0,0 +1,210 @@
+package sarama
+
+import "errors"
+
+// ReceiveTime is a special value for the timestamp field of Offset Commit Requests which
+// tells the broker to set the timestamp to the time at which the request was received.
+// The timestamp is only used if message version 1 is used, which requires kafka 0.8.2.
+const ReceiveTime int64 = -1
+
+// GroupGenerationUndefined is a special value for the group generation field of
+// Offset Commit Requests that should be used when a consumer group does not rely
+// on Kafka for partition management.
+const GroupGenerationUndefined = -1
+
+type offsetCommitRequestBlock struct {
+	offset    int64
+	timestamp int64
+	metadata  string
+}
+
+func (b *offsetCommitRequestBlock) encode(pe packetEncoder, version int16) error {
+	pe.putInt64(b.offset)
+	if version == 1 {
+		pe.putInt64(b.timestamp)
+	} else if b.timestamp != 0 {
+		Logger.Println("Non-zero timestamp specified for OffsetCommitRequest not v1, it will be ignored")
+	}
+
+	return pe.putString(b.metadata)
+}
+
+func (b *offsetCommitRequestBlock) decode(pd packetDecoder, version int16) (err error) {
+	if b.offset, err = pd.getInt64(); err != nil {
+		return err
+	}
+	if version == 1 {
+		if b.timestamp, err = pd.getInt64(); err != nil {
+			return err
+		}
+	}
+	b.metadata, err = pd.getString()
+	return err
+}
+
+type OffsetCommitRequest struct {
+	ConsumerGroup           string
+	ConsumerGroupGeneration int32  // v1 or later
+	ConsumerID              string // v1 or later
+	RetentionTime           int64  // v2 or later
+
+	// Version can be:
+	// - 0 (kafka 0.8.1 and later)
+	// - 1 (kafka 0.8.2 and later)
+	// - 2 (kafka 0.9.0 and later)
+	// - 3 (kafka 0.11.0 and later)
+	// - 4 (kafka 2.0.0 and later)
+	Version int16
+	blocks  map[string]map[int32]*offsetCommitRequestBlock
+}
+
+func (r *OffsetCommitRequest) encode(pe packetEncoder) error {
+	if r.Version < 0 || r.Version > 4 {
+		return PacketEncodingError{"invalid or unsupported OffsetCommitRequest version field"}
+	}
+
+	if err := pe.putString(r.ConsumerGroup); err != nil {
+		return err
+	}
+
+	if r.Version >= 1 {
+		pe.putInt32(r.ConsumerGroupGeneration)
+		if err := pe.putString(r.ConsumerID); err != nil {
+			return err
+		}
+	} else {
+		if r.ConsumerGroupGeneration != 0 {
+			Logger.Println("Non-zero ConsumerGroupGeneration specified for OffsetCommitRequest v0, it will be ignored")
+		}
+		if r.ConsumerID != "" {
+			Logger.Println("Non-empty ConsumerID specified for OffsetCommitRequest v0, it will be ignored")
+		}
+	}
+
+	if r.Version >= 2 {
+		pe.putInt64(r.RetentionTime)
+	} else if r.RetentionTime != 0 {
+		Logger.Println("Non-zero RetentionTime specified for OffsetCommitRequest version <2, it will be ignored")
+	}
+
+	if err := pe.putArrayLength(len(r.blocks)); err != nil {
+		return err
+	}
+	for topic, partitions := range r.blocks {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putArrayLength(len(partitions)); err != nil {
+			return err
+		}
+		for partition, block := range partitions {
+			pe.putInt32(partition)
+			if err := block.encode(pe, r.Version); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (r *OffsetCommitRequest) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+
+	if r.ConsumerGroup, err = pd.getString(); err != nil {
+		return err
+	}
+
+	if r.Version >= 1 {
+		if r.ConsumerGroupGeneration, err = pd.getInt32(); err != nil {
+			return err
+		}
+		if r.ConsumerID, err = pd.getString(); err != nil {
+			return err
+		}
+	}
+
+	if r.Version >= 2 {
+		if r.RetentionTime, err = pd.getInt64(); err != nil {
+			return err
+		}
+	}
+
+	topicCount, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if topicCount == 0 {
+		return nil
+	}
+	r.blocks = make(map[string]map[int32]*offsetCommitRequestBlock)
+	for i := 0; i < topicCount; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		partitionCount, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+		r.blocks[topic] = make(map[int32]*offsetCommitRequestBlock)
+		for j := 0; j < partitionCount; j++ {
+			partition, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+			block := &offsetCommitRequestBlock{}
+			if err := block.decode(pd, r.Version); err != nil {
+				return err
+			}
+			r.blocks[topic][partition] = block
+		}
+	}
+	return nil
+}
+
+func (r *OffsetCommitRequest) key() int16 {
+	return 8
+}
+
+func (r *OffsetCommitRequest) version() int16 {
+	return r.Version
+}
+
+func (r *OffsetCommitRequest) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_8_2_0
+	case 2:
+		return V0_9_0_0
+	case 3:
+		return V0_11_0_0
+	case 4:
+		return V2_0_0_0
+	default:
+		return MinVersion
+	}
+}
+
+func (r *OffsetCommitRequest) AddBlock(topic string, partitionID int32, offset int64, timestamp int64, metadata string) {
+	if r.blocks == nil {
+		r.blocks = make(map[string]map[int32]*offsetCommitRequestBlock)
+	}
+
+	if r.blocks[topic] == nil {
+		r.blocks[topic] = make(map[int32]*offsetCommitRequestBlock)
+	}
+
+	r.blocks[topic][partitionID] = &offsetCommitRequestBlock{offset, timestamp, metadata}
+}
+
+func (r *OffsetCommitRequest) Offset(topic string, partitionID int32) (int64, string, error) {
+	partitions := r.blocks[topic]
+	if partitions == nil {
+		return 0, "", errors.New("no such offset")
+	}
+	block := partitions[partitionID]
+	if block == nil {
+		return 0, "", errors.New("no such offset")
+	}
+	return block.offset, block.metadata, nil
+}
diff --git a/vendor/github.com/Shopify/sarama/offset_commit_response.go b/vendor/github.com/Shopify/sarama/offset_commit_response.go
new file mode 100644
index 0000000..e842298
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/offset_commit_response.go
@@ -0,0 +1,110 @@
+package sarama
+
+type OffsetCommitResponse struct {
+	Version        int16
+	ThrottleTimeMs int32
+	Errors         map[string]map[int32]KError
+}
+
+func (r *OffsetCommitResponse) AddError(topic string, partition int32, kerror KError) {
+	if r.Errors == nil {
+		r.Errors = make(map[string]map[int32]KError)
+	}
+	partitions := r.Errors[topic]
+	if partitions == nil {
+		partitions = make(map[int32]KError)
+		r.Errors[topic] = partitions
+	}
+	partitions[partition] = kerror
+}
+
+func (r *OffsetCommitResponse) encode(pe packetEncoder) error {
+	if r.Version >= 3 {
+		pe.putInt32(r.ThrottleTimeMs)
+	}
+	if err := pe.putArrayLength(len(r.Errors)); err != nil {
+		return err
+	}
+	for topic, partitions := range r.Errors {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putArrayLength(len(partitions)); err != nil {
+			return err
+		}
+		for partition, kerror := range partitions {
+			pe.putInt32(partition)
+			pe.putInt16(int16(kerror))
+		}
+	}
+	return nil
+}
+
+func (r *OffsetCommitResponse) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+
+	if version >= 3 {
+		r.ThrottleTimeMs, err = pd.getInt32()
+		if err != nil {
+			return err
+		}
+	}
+
+	numTopics, err := pd.getArrayLength()
+	if err != nil || numTopics == 0 {
+		return err
+	}
+
+	r.Errors = make(map[string]map[int32]KError, numTopics)
+	for i := 0; i < numTopics; i++ {
+		name, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		numErrors, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+
+		r.Errors[name] = make(map[int32]KError, numErrors)
+
+		for j := 0; j < numErrors; j++ {
+			id, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+
+			tmp, err := pd.getInt16()
+			if err != nil {
+				return err
+			}
+			r.Errors[name][id] = KError(tmp)
+		}
+	}
+
+	return nil
+}
+
+func (r *OffsetCommitResponse) key() int16 {
+	return 8
+}
+
+func (r *OffsetCommitResponse) version() int16 {
+	return r.Version
+}
+
+func (r *OffsetCommitResponse) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_8_2_0
+	case 2:
+		return V0_9_0_0
+	case 3:
+		return V0_11_0_0
+	case 4:
+		return V2_0_0_0
+	default:
+		return MinVersion
+	}
+}
diff --git a/vendor/github.com/Shopify/sarama/offset_fetch_request.go b/vendor/github.com/Shopify/sarama/offset_fetch_request.go
new file mode 100644
index 0000000..6860824
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/offset_fetch_request.go
@@ -0,0 +1,100 @@
+package sarama
+
+type OffsetFetchRequest struct {
+	Version       int16
+	ConsumerGroup string
+	partitions    map[string][]int32
+}
+
+func (r *OffsetFetchRequest) encode(pe packetEncoder) (err error) {
+	if r.Version < 0 || r.Version > 5 {
+		return PacketEncodingError{"invalid or unsupported OffsetFetchRequest version field"}
+	}
+
+	if err = pe.putString(r.ConsumerGroup); err != nil {
+		return err
+	}
+
+	if r.Version >= 2 && r.partitions == nil {
+		pe.putInt32(-1)
+	} else {
+		if err = pe.putArrayLength(len(r.partitions)); err != nil {
+			return err
+		}
+		for topic, partitions := range r.partitions {
+			if err = pe.putString(topic); err != nil {
+				return err
+			}
+			if err = pe.putInt32Array(partitions); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (r *OffsetFetchRequest) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+	if r.ConsumerGroup, err = pd.getString(); err != nil {
+		return err
+	}
+	partitionCount, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if (partitionCount == 0 && version < 2) || partitionCount < 0 {
+		return nil
+	}
+	r.partitions = make(map[string][]int32)
+	for i := 0; i < partitionCount; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		partitions, err := pd.getInt32Array()
+		if err != nil {
+			return err
+		}
+		r.partitions[topic] = partitions
+	}
+	return nil
+}
+
+func (r *OffsetFetchRequest) key() int16 {
+	return 9
+}
+
+func (r *OffsetFetchRequest) version() int16 {
+	return r.Version
+}
+
+func (r *OffsetFetchRequest) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_8_2_0
+	case 2:
+		return V0_10_2_0
+	case 3:
+		return V0_11_0_0
+	case 4:
+		return V2_0_0_0
+	case 5:
+		return V2_1_0_0
+	default:
+		return MinVersion
+	}
+}
+
+func (r *OffsetFetchRequest) ZeroPartitions() {
+	if r.partitions == nil && r.Version >= 2 {
+		r.partitions = make(map[string][]int32)
+	}
+}
+
+func (r *OffsetFetchRequest) AddPartition(topic string, partitionID int32) {
+	if r.partitions == nil {
+		r.partitions = make(map[string][]int32)
+	}
+
+	r.partitions[topic] = append(r.partitions[topic], partitionID)
+}
diff --git a/vendor/github.com/Shopify/sarama/offset_fetch_response.go b/vendor/github.com/Shopify/sarama/offset_fetch_response.go
new file mode 100644
index 0000000..9e25702
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/offset_fetch_response.go
@@ -0,0 +1,197 @@
+package sarama
+
+type OffsetFetchResponseBlock struct {
+	Offset      int64
+	LeaderEpoch int32
+	Metadata    string
+	Err         KError
+}
+
+func (b *OffsetFetchResponseBlock) decode(pd packetDecoder, version int16) (err error) {
+	b.Offset, err = pd.getInt64()
+	if err != nil {
+		return err
+	}
+
+	if version >= 5 {
+		b.LeaderEpoch, err = pd.getInt32()
+		if err != nil {
+			return err
+		}
+	}
+
+	b.Metadata, err = pd.getString()
+	if err != nil {
+		return err
+	}
+
+	tmp, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	b.Err = KError(tmp)
+
+	return nil
+}
+
+func (b *OffsetFetchResponseBlock) encode(pe packetEncoder, version int16) (err error) {
+	pe.putInt64(b.Offset)
+
+	if version >= 5 {
+		pe.putInt32(b.LeaderEpoch)
+	}
+
+	err = pe.putString(b.Metadata)
+	if err != nil {
+		return err
+	}
+
+	pe.putInt16(int16(b.Err))
+
+	return nil
+}
+
+type OffsetFetchResponse struct {
+	Version        int16
+	ThrottleTimeMs int32
+	Blocks         map[string]map[int32]*OffsetFetchResponseBlock
+	Err            KError
+}
+
+func (r *OffsetFetchResponse) encode(pe packetEncoder) error {
+	if r.Version >= 3 {
+		pe.putInt32(r.ThrottleTimeMs)
+	}
+
+	if err := pe.putArrayLength(len(r.Blocks)); err != nil {
+		return err
+	}
+	for topic, partitions := range r.Blocks {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putArrayLength(len(partitions)); err != nil {
+			return err
+		}
+		for partition, block := range partitions {
+			pe.putInt32(partition)
+			if err := block.encode(pe, r.Version); err != nil {
+				return err
+			}
+		}
+	}
+	if r.Version >= 2 {
+		pe.putInt16(int16(r.Err))
+	}
+	return nil
+}
+
+func (r *OffsetFetchResponse) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+
+	if version >= 3 {
+		r.ThrottleTimeMs, err = pd.getInt32()
+		if err != nil {
+			return err
+		}
+	}
+
+	numTopics, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	if numTopics > 0 {
+		r.Blocks = make(map[string]map[int32]*OffsetFetchResponseBlock, numTopics)
+		for i := 0; i < numTopics; i++ {
+			name, err := pd.getString()
+			if err != nil {
+				return err
+			}
+
+			numBlocks, err := pd.getArrayLength()
+			if err != nil {
+				return err
+			}
+
+			if numBlocks == 0 {
+				r.Blocks[name] = nil
+				continue
+			}
+			r.Blocks[name] = make(map[int32]*OffsetFetchResponseBlock, numBlocks)
+
+			for j := 0; j < numBlocks; j++ {
+				id, err := pd.getInt32()
+				if err != nil {
+					return err
+				}
+
+				block := new(OffsetFetchResponseBlock)
+				err = block.decode(pd, version)
+				if err != nil {
+					return err
+				}
+				r.Blocks[name][id] = block
+			}
+		}
+	}
+
+	if version >= 2 {
+		kerr, err := pd.getInt16()
+		if err != nil {
+			return err
+		}
+		r.Err = KError(kerr)
+	}
+
+	return nil
+}
+
+func (r *OffsetFetchResponse) key() int16 {
+	return 9
+}
+
+func (r *OffsetFetchResponse) version() int16 {
+	return r.Version
+}
+
+func (r *OffsetFetchResponse) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_8_2_0
+	case 2:
+		return V0_10_2_0
+	case 3:
+		return V0_11_0_0
+	case 4:
+		return V2_0_0_0
+	case 5:
+		return V2_1_0_0
+	default:
+		return MinVersion
+	}
+}
+
+func (r *OffsetFetchResponse) GetBlock(topic string, partition int32) *OffsetFetchResponseBlock {
+	if r.Blocks == nil {
+		return nil
+	}
+
+	if r.Blocks[topic] == nil {
+		return nil
+	}
+
+	return r.Blocks[topic][partition]
+}
+
+func (r *OffsetFetchResponse) AddBlock(topic string, partition int32, block *OffsetFetchResponseBlock) {
+	if r.Blocks == nil {
+		r.Blocks = make(map[string]map[int32]*OffsetFetchResponseBlock)
+	}
+	partitions := r.Blocks[topic]
+	if partitions == nil {
+		partitions = make(map[int32]*OffsetFetchResponseBlock)
+		r.Blocks[topic] = partitions
+	}
+	partitions[partition] = block
+}
diff --git a/vendor/github.com/Shopify/sarama/offset_manager.go b/vendor/github.com/Shopify/sarama/offset_manager.go
new file mode 100644
index 0000000..e40f429
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/offset_manager.go
@@ -0,0 +1,585 @@
+package sarama
+
+import (
+	"sync"
+	"time"
+)
+
+// Offset Manager
+
+// OffsetManager uses Kafka to store and fetch consumed partition offsets.
+type OffsetManager interface {
+	// ManagePartition creates a PartitionOffsetManager on the given topic/partition.
+	// It will return an error if this OffsetManager is already managing the given
+	// topic/partition.
+	ManagePartition(topic string, partition int32) (PartitionOffsetManager, error)
+
+	// Close stops the OffsetManager from managing offsets. It is required to call
+	// this function before an OffsetManager object passes out of scope, as it
+	// will otherwise leak memory. You must call this after all the
+	// PartitionOffsetManagers are closed.
+	Close() error
+}
+
+type offsetManager struct {
+	client Client
+	conf   *Config
+	group  string
+	ticker *time.Ticker
+
+	memberID   string
+	generation int32
+
+	broker     *Broker
+	brokerLock sync.RWMutex
+
+	poms     map[string]map[int32]*partitionOffsetManager
+	pomsLock sync.RWMutex
+
+	closeOnce sync.Once
+	closing   chan none
+	closed    chan none
+}
+
+// NewOffsetManagerFromClient creates a new OffsetManager from the given client.
+// It is still necessary to call Close() on the underlying client when finished with the partition manager.
+func NewOffsetManagerFromClient(group string, client Client) (OffsetManager, error) {
+	return newOffsetManagerFromClient(group, "", GroupGenerationUndefined, client)
+}
+
+func newOffsetManagerFromClient(group, memberID string, generation int32, client Client) (*offsetManager, error) {
+	// Check that we are not dealing with a closed Client before processing any other arguments
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	conf := client.Config()
+	om := &offsetManager{
+		client: client,
+		conf:   conf,
+		group:  group,
+		ticker: time.NewTicker(conf.Consumer.Offsets.AutoCommit.Interval),
+		poms:   make(map[string]map[int32]*partitionOffsetManager),
+
+		memberID:   memberID,
+		generation: generation,
+
+		closing: make(chan none),
+		closed:  make(chan none),
+	}
+	go withRecover(om.mainLoop)
+
+	return om, nil
+}
+
+func (om *offsetManager) ManagePartition(topic string, partition int32) (PartitionOffsetManager, error) {
+	pom, err := om.newPartitionOffsetManager(topic, partition)
+	if err != nil {
+		return nil, err
+	}
+
+	om.pomsLock.Lock()
+	defer om.pomsLock.Unlock()
+
+	topicManagers := om.poms[topic]
+	if topicManagers == nil {
+		topicManagers = make(map[int32]*partitionOffsetManager)
+		om.poms[topic] = topicManagers
+	}
+
+	if topicManagers[partition] != nil {
+		return nil, ConfigurationError("That topic/partition is already being managed")
+	}
+
+	topicManagers[partition] = pom
+	return pom, nil
+}
+
+func (om *offsetManager) Close() error {
+	om.closeOnce.Do(func() {
+		// exit the mainLoop
+		close(om.closing)
+		<-om.closed
+
+		// mark all POMs as closed
+		om.asyncClosePOMs()
+
+		// flush one last time
+		for attempt := 0; attempt <= om.conf.Consumer.Offsets.Retry.Max; attempt++ {
+			om.flushToBroker()
+			if om.releasePOMs(false) == 0 {
+				break
+			}
+		}
+
+		om.releasePOMs(true)
+		om.brokerLock.Lock()
+		om.broker = nil
+		om.brokerLock.Unlock()
+	})
+	return nil
+}
+
+func (om *offsetManager) computeBackoff(retries int) time.Duration {
+	if om.conf.Metadata.Retry.BackoffFunc != nil {
+		return om.conf.Metadata.Retry.BackoffFunc(retries, om.conf.Metadata.Retry.Max)
+	} else {
+		return om.conf.Metadata.Retry.Backoff
+	}
+}
+
+func (om *offsetManager) fetchInitialOffset(topic string, partition int32, retries int) (int64, string, error) {
+	broker, err := om.coordinator()
+	if err != nil {
+		if retries <= 0 {
+			return 0, "", err
+		}
+		return om.fetchInitialOffset(topic, partition, retries-1)
+	}
+
+	req := new(OffsetFetchRequest)
+	req.Version = 1
+	req.ConsumerGroup = om.group
+	req.AddPartition(topic, partition)
+
+	resp, err := broker.FetchOffset(req)
+	if err != nil {
+		if retries <= 0 {
+			return 0, "", err
+		}
+		om.releaseCoordinator(broker)
+		return om.fetchInitialOffset(topic, partition, retries-1)
+	}
+
+	block := resp.GetBlock(topic, partition)
+	if block == nil {
+		return 0, "", ErrIncompleteResponse
+	}
+
+	switch block.Err {
+	case ErrNoError:
+		return block.Offset, block.Metadata, nil
+	case ErrNotCoordinatorForConsumer:
+		if retries <= 0 {
+			return 0, "", block.Err
+		}
+		om.releaseCoordinator(broker)
+		return om.fetchInitialOffset(topic, partition, retries-1)
+	case ErrOffsetsLoadInProgress:
+		if retries <= 0 {
+			return 0, "", block.Err
+		}
+		backoff := om.computeBackoff(retries)
+		select {
+		case <-om.closing:
+			return 0, "", block.Err
+		case <-time.After(backoff):
+		}
+		return om.fetchInitialOffset(topic, partition, retries-1)
+	default:
+		return 0, "", block.Err
+	}
+}
+
+func (om *offsetManager) coordinator() (*Broker, error) {
+	om.brokerLock.RLock()
+	broker := om.broker
+	om.brokerLock.RUnlock()
+
+	if broker != nil {
+		return broker, nil
+	}
+
+	om.brokerLock.Lock()
+	defer om.brokerLock.Unlock()
+
+	if broker := om.broker; broker != nil {
+		return broker, nil
+	}
+
+	if err := om.client.RefreshCoordinator(om.group); err != nil {
+		return nil, err
+	}
+
+	broker, err := om.client.Coordinator(om.group)
+	if err != nil {
+		return nil, err
+	}
+
+	om.broker = broker
+	return broker, nil
+}
+
+func (om *offsetManager) releaseCoordinator(b *Broker) {
+	om.brokerLock.Lock()
+	if om.broker == b {
+		om.broker = nil
+	}
+	om.brokerLock.Unlock()
+}
+
+func (om *offsetManager) mainLoop() {
+	defer om.ticker.Stop()
+	defer close(om.closed)
+
+	for {
+		select {
+		case <-om.ticker.C:
+			om.flushToBroker()
+			om.releasePOMs(false)
+		case <-om.closing:
+			return
+		}
+	}
+}
+
+// flushToBroker is ignored if auto-commit offsets is disabled
+func (om *offsetManager) flushToBroker() {
+	if !om.conf.Consumer.Offsets.AutoCommit.Enable {
+		return
+	}
+
+	req := om.constructRequest()
+	if req == nil {
+		return
+	}
+
+	broker, err := om.coordinator()
+	if err != nil {
+		om.handleError(err)
+		return
+	}
+
+	resp, err := broker.CommitOffset(req)
+	if err != nil {
+		om.handleError(err)
+		om.releaseCoordinator(broker)
+		_ = broker.Close()
+		return
+	}
+
+	om.handleResponse(broker, req, resp)
+}
+
+func (om *offsetManager) constructRequest() *OffsetCommitRequest {
+	var r *OffsetCommitRequest
+	var perPartitionTimestamp int64
+	if om.conf.Consumer.Offsets.Retention == 0 {
+		perPartitionTimestamp = ReceiveTime
+		r = &OffsetCommitRequest{
+			Version:                 1,
+			ConsumerGroup:           om.group,
+			ConsumerID:              om.memberID,
+			ConsumerGroupGeneration: om.generation,
+		}
+	} else {
+		r = &OffsetCommitRequest{
+			Version:                 2,
+			RetentionTime:           int64(om.conf.Consumer.Offsets.Retention / time.Millisecond),
+			ConsumerGroup:           om.group,
+			ConsumerID:              om.memberID,
+			ConsumerGroupGeneration: om.generation,
+		}
+
+	}
+
+	om.pomsLock.RLock()
+	defer om.pomsLock.RUnlock()
+
+	for _, topicManagers := range om.poms {
+		for _, pom := range topicManagers {
+			pom.lock.Lock()
+			if pom.dirty {
+				r.AddBlock(pom.topic, pom.partition, pom.offset, perPartitionTimestamp, pom.metadata)
+			}
+			pom.lock.Unlock()
+		}
+	}
+
+	if len(r.blocks) > 0 {
+		return r
+	}
+
+	return nil
+}
+
+func (om *offsetManager) handleResponse(broker *Broker, req *OffsetCommitRequest, resp *OffsetCommitResponse) {
+	om.pomsLock.RLock()
+	defer om.pomsLock.RUnlock()
+
+	for _, topicManagers := range om.poms {
+		for _, pom := range topicManagers {
+			if req.blocks[pom.topic] == nil || req.blocks[pom.topic][pom.partition] == nil {
+				continue
+			}
+
+			var err KError
+			var ok bool
+
+			if resp.Errors[pom.topic] == nil {
+				pom.handleError(ErrIncompleteResponse)
+				continue
+			}
+			if err, ok = resp.Errors[pom.topic][pom.partition]; !ok {
+				pom.handleError(ErrIncompleteResponse)
+				continue
+			}
+
+			switch err {
+			case ErrNoError:
+				block := req.blocks[pom.topic][pom.partition]
+				pom.updateCommitted(block.offset, block.metadata)
+			case ErrNotLeaderForPartition, ErrLeaderNotAvailable,
+				ErrConsumerCoordinatorNotAvailable, ErrNotCoordinatorForConsumer:
+				// not a critical error, we just need to redispatch
+				om.releaseCoordinator(broker)
+			case ErrOffsetMetadataTooLarge, ErrInvalidCommitOffsetSize:
+				// nothing we can do about this, just tell the user and carry on
+				pom.handleError(err)
+			case ErrOffsetsLoadInProgress:
+				// nothing wrong but we didn't commit, we'll get it next time round
+			case ErrUnknownTopicOrPartition:
+				// let the user know *and* try redispatching - if topic-auto-create is
+				// enabled, redispatching should trigger a metadata req and create the
+				// topic; if not then re-dispatching won't help, but we've let the user
+				// know and it shouldn't hurt either (see https://github.com/Shopify/sarama/issues/706)
+				fallthrough
+			default:
+				// dunno, tell the user and try redispatching
+				pom.handleError(err)
+				om.releaseCoordinator(broker)
+			}
+		}
+	}
+}
+
+func (om *offsetManager) handleError(err error) {
+	om.pomsLock.RLock()
+	defer om.pomsLock.RUnlock()
+
+	for _, topicManagers := range om.poms {
+		for _, pom := range topicManagers {
+			pom.handleError(err)
+		}
+	}
+}
+
+func (om *offsetManager) asyncClosePOMs() {
+	om.pomsLock.RLock()
+	defer om.pomsLock.RUnlock()
+
+	for _, topicManagers := range om.poms {
+		for _, pom := range topicManagers {
+			pom.AsyncClose()
+		}
+	}
+}
+
+// Releases/removes closed POMs once they are clean (or when forced)
+func (om *offsetManager) releasePOMs(force bool) (remaining int) {
+	om.pomsLock.Lock()
+	defer om.pomsLock.Unlock()
+
+	for topic, topicManagers := range om.poms {
+		for partition, pom := range topicManagers {
+			pom.lock.Lock()
+			releaseDue := pom.done && (force || !pom.dirty)
+			pom.lock.Unlock()
+
+			if releaseDue {
+				pom.release()
+
+				delete(om.poms[topic], partition)
+				if len(om.poms[topic]) == 0 {
+					delete(om.poms, topic)
+				}
+			}
+		}
+		remaining += len(om.poms[topic])
+	}
+	return
+}
+
+func (om *offsetManager) findPOM(topic string, partition int32) *partitionOffsetManager {
+	om.pomsLock.RLock()
+	defer om.pomsLock.RUnlock()
+
+	if partitions, ok := om.poms[topic]; ok {
+		if pom, ok := partitions[partition]; ok {
+			return pom
+		}
+	}
+	return nil
+}
+
+// Partition Offset Manager
+
+// PartitionOffsetManager uses Kafka to store and fetch consumed partition offsets. You MUST call Close()
+// on a partition offset manager to avoid leaks, it will not be garbage-collected automatically when it passes
+// out of scope.
+type PartitionOffsetManager interface {
+	// NextOffset returns the next offset that should be consumed for the managed
+	// partition, accompanied by metadata which can be used to reconstruct the state
+	// of the partition consumer when it resumes. NextOffset() will return
+	// `config.Consumer.Offsets.Initial` and an empty metadata string if no offset
+	// was committed for this partition yet.
+	NextOffset() (int64, string)
+
+	// MarkOffset marks the provided offset, alongside a metadata string
+	// that represents the state of the partition consumer at that point in time. The
+	// metadata string can be used by another consumer to restore that state, so it
+	// can resume consumption.
+	//
+	// To follow upstream conventions, you are expected to mark the offset of the
+	// next message to read, not the last message read. Thus, when calling `MarkOffset`
+	// you should typically add one to the offset of the last consumed message.
+	//
+	// Note: calling MarkOffset does not necessarily commit the offset to the backend
+	// store immediately for efficiency reasons, and it may never be committed if
+	// your application crashes. This means that you may end up processing the same
+	// message twice, and your processing should ideally be idempotent.
+	MarkOffset(offset int64, metadata string)
+
+	// ResetOffset resets to the provided offset, alongside a metadata string that
+	// represents the state of the partition consumer at that point in time. Reset
+	// acts as a counterpart to MarkOffset, the difference being that it allows to
+	// reset an offset to an earlier or smaller value, where MarkOffset only
+	// allows incrementing the offset. cf MarkOffset for more details.
+	ResetOffset(offset int64, metadata string)
+
+	// Errors returns a read channel of errors that occur during offset management, if
+	// enabled. By default, errors are logged and not returned over this channel. If
+	// you want to implement any custom error handling, set your config's
+	// Consumer.Return.Errors setting to true, and read from this channel.
+	Errors() <-chan *ConsumerError
+
+	// AsyncClose initiates a shutdown of the PartitionOffsetManager. This method will
+	// return immediately, after which you should wait until the 'errors' channel has
+	// been drained and closed. It is required to call this function, or Close before
+	// a consumer object passes out of scope, as it will otherwise leak memory. You
+	// must call this before calling Close on the underlying client.
+	AsyncClose()
+
+	// Close stops the PartitionOffsetManager from managing offsets. It is required to
+	// call this function (or AsyncClose) before a PartitionOffsetManager object
+	// passes out of scope, as it will otherwise leak memory. You must call this
+	// before calling Close on the underlying client.
+	Close() error
+}
+
+type partitionOffsetManager struct {
+	parent    *offsetManager
+	topic     string
+	partition int32
+
+	lock     sync.Mutex
+	offset   int64
+	metadata string
+	dirty    bool
+	done     bool
+
+	releaseOnce sync.Once
+	errors      chan *ConsumerError
+}
+
+func (om *offsetManager) newPartitionOffsetManager(topic string, partition int32) (*partitionOffsetManager, error) {
+	offset, metadata, err := om.fetchInitialOffset(topic, partition, om.conf.Metadata.Retry.Max)
+	if err != nil {
+		return nil, err
+	}
+
+	return &partitionOffsetManager{
+		parent:    om,
+		topic:     topic,
+		partition: partition,
+		errors:    make(chan *ConsumerError, om.conf.ChannelBufferSize),
+		offset:    offset,
+		metadata:  metadata,
+	}, nil
+}
+
+func (pom *partitionOffsetManager) Errors() <-chan *ConsumerError {
+	return pom.errors
+}
+
+func (pom *partitionOffsetManager) MarkOffset(offset int64, metadata string) {
+	pom.lock.Lock()
+	defer pom.lock.Unlock()
+
+	if offset > pom.offset {
+		pom.offset = offset
+		pom.metadata = metadata
+		pom.dirty = true
+	}
+}
+
+func (pom *partitionOffsetManager) ResetOffset(offset int64, metadata string) {
+	pom.lock.Lock()
+	defer pom.lock.Unlock()
+
+	if offset <= pom.offset {
+		pom.offset = offset
+		pom.metadata = metadata
+		pom.dirty = true
+	}
+}
+
+func (pom *partitionOffsetManager) updateCommitted(offset int64, metadata string) {
+	pom.lock.Lock()
+	defer pom.lock.Unlock()
+
+	if pom.offset == offset && pom.metadata == metadata {
+		pom.dirty = false
+	}
+}
+
+func (pom *partitionOffsetManager) NextOffset() (int64, string) {
+	pom.lock.Lock()
+	defer pom.lock.Unlock()
+
+	if pom.offset >= 0 {
+		return pom.offset, pom.metadata
+	}
+
+	return pom.parent.conf.Consumer.Offsets.Initial, ""
+}
+
+func (pom *partitionOffsetManager) AsyncClose() {
+	pom.lock.Lock()
+	pom.done = true
+	pom.lock.Unlock()
+}
+
+func (pom *partitionOffsetManager) Close() error {
+	pom.AsyncClose()
+
+	var errors ConsumerErrors
+	for err := range pom.errors {
+		errors = append(errors, err)
+	}
+
+	if len(errors) > 0 {
+		return errors
+	}
+	return nil
+}
+
+func (pom *partitionOffsetManager) handleError(err error) {
+	cErr := &ConsumerError{
+		Topic:     pom.topic,
+		Partition: pom.partition,
+		Err:       err,
+	}
+
+	if pom.parent.conf.Consumer.Return.Errors {
+		pom.errors <- cErr
+	} else {
+		Logger.Println(cErr)
+	}
+}
+
+func (pom *partitionOffsetManager) release() {
+	pom.releaseOnce.Do(func() {
+		close(pom.errors)
+	})
+}
diff --git a/vendor/github.com/Shopify/sarama/offset_request.go b/vendor/github.com/Shopify/sarama/offset_request.go
new file mode 100644
index 0000000..326c372
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/offset_request.go
@@ -0,0 +1,156 @@
+package sarama
+
+type offsetRequestBlock struct {
+	time       int64
+	maxOffsets int32 // Only used in version 0
+}
+
+func (b *offsetRequestBlock) encode(pe packetEncoder, version int16) error {
+	pe.putInt64(int64(b.time))
+	if version == 0 {
+		pe.putInt32(b.maxOffsets)
+	}
+
+	return nil
+}
+
+func (b *offsetRequestBlock) decode(pd packetDecoder, version int16) (err error) {
+	if b.time, err = pd.getInt64(); err != nil {
+		return err
+	}
+	if version == 0 {
+		if b.maxOffsets, err = pd.getInt32(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+type OffsetRequest struct {
+	Version        int16
+	replicaID      int32
+	isReplicaIDSet bool
+	blocks         map[string]map[int32]*offsetRequestBlock
+}
+
+func (r *OffsetRequest) encode(pe packetEncoder) error {
+	if r.isReplicaIDSet {
+		pe.putInt32(r.replicaID)
+	} else {
+		// default replica ID is always -1 for clients
+		pe.putInt32(-1)
+	}
+
+	err := pe.putArrayLength(len(r.blocks))
+	if err != nil {
+		return err
+	}
+	for topic, partitions := range r.blocks {
+		err = pe.putString(topic)
+		if err != nil {
+			return err
+		}
+		err = pe.putArrayLength(len(partitions))
+		if err != nil {
+			return err
+		}
+		for partition, block := range partitions {
+			pe.putInt32(partition)
+			if err = block.encode(pe, r.Version); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (r *OffsetRequest) decode(pd packetDecoder, version int16) error {
+	r.Version = version
+
+	replicaID, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	if replicaID >= 0 {
+		r.SetReplicaID(replicaID)
+	}
+
+	blockCount, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if blockCount == 0 {
+		return nil
+	}
+	r.blocks = make(map[string]map[int32]*offsetRequestBlock)
+	for i := 0; i < blockCount; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		partitionCount, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+		r.blocks[topic] = make(map[int32]*offsetRequestBlock)
+		for j := 0; j < partitionCount; j++ {
+			partition, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+			block := &offsetRequestBlock{}
+			if err := block.decode(pd, version); err != nil {
+				return err
+			}
+			r.blocks[topic][partition] = block
+		}
+	}
+	return nil
+}
+
+func (r *OffsetRequest) key() int16 {
+	return 2
+}
+
+func (r *OffsetRequest) version() int16 {
+	return r.Version
+}
+
+func (r *OffsetRequest) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_10_1_0
+	default:
+		return MinVersion
+	}
+}
+
+func (r *OffsetRequest) SetReplicaID(id int32) {
+	r.replicaID = id
+	r.isReplicaIDSet = true
+}
+
+func (r *OffsetRequest) ReplicaID() int32 {
+	if r.isReplicaIDSet {
+		return r.replicaID
+	}
+	return -1
+}
+
+func (r *OffsetRequest) AddBlock(topic string, partitionID int32, time int64, maxOffsets int32) {
+	if r.blocks == nil {
+		r.blocks = make(map[string]map[int32]*offsetRequestBlock)
+	}
+
+	if r.blocks[topic] == nil {
+		r.blocks[topic] = make(map[int32]*offsetRequestBlock)
+	}
+
+	tmp := new(offsetRequestBlock)
+	tmp.time = time
+	if r.Version == 0 {
+		tmp.maxOffsets = maxOffsets
+	}
+
+	r.blocks[topic][partitionID] = tmp
+}
diff --git a/vendor/github.com/Shopify/sarama/offset_response.go b/vendor/github.com/Shopify/sarama/offset_response.go
new file mode 100644
index 0000000..8b2193f
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/offset_response.go
@@ -0,0 +1,174 @@
+package sarama
+
+type OffsetResponseBlock struct {
+	Err       KError
+	Offsets   []int64 // Version 0
+	Offset    int64   // Version 1
+	Timestamp int64   // Version 1
+}
+
+func (b *OffsetResponseBlock) decode(pd packetDecoder, version int16) (err error) {
+	tmp, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	b.Err = KError(tmp)
+
+	if version == 0 {
+		b.Offsets, err = pd.getInt64Array()
+
+		return err
+	}
+
+	b.Timestamp, err = pd.getInt64()
+	if err != nil {
+		return err
+	}
+
+	b.Offset, err = pd.getInt64()
+	if err != nil {
+		return err
+	}
+
+	// For backwards compatibility put the offset in the offsets array too
+	b.Offsets = []int64{b.Offset}
+
+	return nil
+}
+
+func (b *OffsetResponseBlock) encode(pe packetEncoder, version int16) (err error) {
+	pe.putInt16(int16(b.Err))
+
+	if version == 0 {
+		return pe.putInt64Array(b.Offsets)
+	}
+
+	pe.putInt64(b.Timestamp)
+	pe.putInt64(b.Offset)
+
+	return nil
+}
+
+type OffsetResponse struct {
+	Version int16
+	Blocks  map[string]map[int32]*OffsetResponseBlock
+}
+
+func (r *OffsetResponse) decode(pd packetDecoder, version int16) (err error) {
+	numTopics, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Blocks = make(map[string]map[int32]*OffsetResponseBlock, numTopics)
+	for i := 0; i < numTopics; i++ {
+		name, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		numBlocks, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+
+		r.Blocks[name] = make(map[int32]*OffsetResponseBlock, numBlocks)
+
+		for j := 0; j < numBlocks; j++ {
+			id, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+
+			block := new(OffsetResponseBlock)
+			err = block.decode(pd, version)
+			if err != nil {
+				return err
+			}
+			r.Blocks[name][id] = block
+		}
+	}
+
+	return nil
+}
+
+func (r *OffsetResponse) GetBlock(topic string, partition int32) *OffsetResponseBlock {
+	if r.Blocks == nil {
+		return nil
+	}
+
+	if r.Blocks[topic] == nil {
+		return nil
+	}
+
+	return r.Blocks[topic][partition]
+}
+
+/*
+// [0 0 0 1 ntopics
+0 8 109 121 95 116 111 112 105 99 topic
+0 0 0 1 npartitions
+0 0 0 0 id
+0 0
+
+0 0 0 1 0 0 0 0
+0 1 1 1 0 0 0 1
+0 8 109 121 95 116 111 112
+105 99 0 0 0 1 0 0
+0 0 0 0 0 0 0 1
+0 0 0 0 0 1 1 1] <nil>
+
+*/
+func (r *OffsetResponse) encode(pe packetEncoder) (err error) {
+	if err = pe.putArrayLength(len(r.Blocks)); err != nil {
+		return err
+	}
+
+	for topic, partitions := range r.Blocks {
+		if err = pe.putString(topic); err != nil {
+			return err
+		}
+		if err = pe.putArrayLength(len(partitions)); err != nil {
+			return err
+		}
+		for partition, block := range partitions {
+			pe.putInt32(partition)
+			if err = block.encode(pe, r.version()); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (r *OffsetResponse) key() int16 {
+	return 2
+}
+
+func (r *OffsetResponse) version() int16 {
+	return r.Version
+}
+
+func (r *OffsetResponse) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_10_1_0
+	default:
+		return MinVersion
+	}
+}
+
+// testing API
+
+func (r *OffsetResponse) AddTopicPartition(topic string, partition int32, offset int64) {
+	if r.Blocks == nil {
+		r.Blocks = make(map[string]map[int32]*OffsetResponseBlock)
+	}
+	byTopic, ok := r.Blocks[topic]
+	if !ok {
+		byTopic = make(map[int32]*OffsetResponseBlock)
+		r.Blocks[topic] = byTopic
+	}
+	byTopic[partition] = &OffsetResponseBlock{Offsets: []int64{offset}, Offset: offset}
+}
diff --git a/vendor/github.com/Shopify/sarama/packet_decoder.go b/vendor/github.com/Shopify/sarama/packet_decoder.go
new file mode 100644
index 0000000..9be854c
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/packet_decoder.go
@@ -0,0 +1,61 @@
+package sarama
+
+// PacketDecoder is the interface providing helpers for reading with Kafka's encoding rules.
+// Types implementing Decoder only need to worry about calling methods like GetString,
+// not about how a string is represented in Kafka.
+type packetDecoder interface {
+	// Primitives
+	getInt8() (int8, error)
+	getInt16() (int16, error)
+	getInt32() (int32, error)
+	getInt64() (int64, error)
+	getVarint() (int64, error)
+	getArrayLength() (int, error)
+	getBool() (bool, error)
+
+	// Collections
+	getBytes() ([]byte, error)
+	getVarintBytes() ([]byte, error)
+	getRawBytes(length int) ([]byte, error)
+	getString() (string, error)
+	getNullableString() (*string, error)
+	getInt32Array() ([]int32, error)
+	getInt64Array() ([]int64, error)
+	getStringArray() ([]string, error)
+
+	// Subsets
+	remaining() int
+	getSubset(length int) (packetDecoder, error)
+	peek(offset, length int) (packetDecoder, error) // similar to getSubset, but it doesn't advance the offset
+	peekInt8(offset int) (int8, error)              // similar to peek, but just one byte
+
+	// Stacks, see PushDecoder
+	push(in pushDecoder) error
+	pop() error
+}
+
+// PushDecoder is the interface for decoding fields like CRCs and lengths where the validity
+// of the field depends on what is after it in the packet. Start them with PacketDecoder.Push() where
+// the actual value is located in the packet, then PacketDecoder.Pop() them when all the bytes they
+// depend upon have been decoded.
+type pushDecoder interface {
+	// Saves the offset into the input buffer as the location to actually read the calculated value when able.
+	saveOffset(in int)
+
+	// Returns the length of data to reserve for the input of this encoder (eg 4 bytes for a CRC32).
+	reserveLength() int
+
+	// Indicates that all required data is now available to calculate and check the field.
+	// SaveOffset is guaranteed to have been called first. The implementation should read ReserveLength() bytes
+	// of data from the saved offset, and verify it based on the data between the saved offset and curOffset.
+	check(curOffset int, buf []byte) error
+}
+
+// dynamicPushDecoder extends the interface of pushDecoder for uses cases where the length of the
+// fields itself is unknown until its value was decoded (for instance varint encoded length
+// fields).
+// During push, dynamicPushDecoder.decode() method will be called instead of reserveLength()
+type dynamicPushDecoder interface {
+	pushDecoder
+	decoder
+}
diff --git a/vendor/github.com/Shopify/sarama/packet_encoder.go b/vendor/github.com/Shopify/sarama/packet_encoder.go
new file mode 100644
index 0000000..67b8dae
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/packet_encoder.go
@@ -0,0 +1,65 @@
+package sarama
+
+import "github.com/rcrowley/go-metrics"
+
+// PacketEncoder is the interface providing helpers for writing with Kafka's encoding rules.
+// Types implementing Encoder only need to worry about calling methods like PutString,
+// not about how a string is represented in Kafka.
+type packetEncoder interface {
+	// Primitives
+	putInt8(in int8)
+	putInt16(in int16)
+	putInt32(in int32)
+	putInt64(in int64)
+	putVarint(in int64)
+	putArrayLength(in int) error
+	putBool(in bool)
+
+	// Collections
+	putBytes(in []byte) error
+	putVarintBytes(in []byte) error
+	putRawBytes(in []byte) error
+	putString(in string) error
+	putNullableString(in *string) error
+	putStringArray(in []string) error
+	putInt32Array(in []int32) error
+	putInt64Array(in []int64) error
+
+	// Provide the current offset to record the batch size metric
+	offset() int
+
+	// Stacks, see PushEncoder
+	push(in pushEncoder)
+	pop() error
+
+	// To record metrics when provided
+	metricRegistry() metrics.Registry
+}
+
+// PushEncoder is the interface for encoding fields like CRCs and lengths where the value
+// of the field depends on what is encoded after it in the packet. Start them with PacketEncoder.Push() where
+// the actual value is located in the packet, then PacketEncoder.Pop() them when all the bytes they
+// depend upon have been written.
+type pushEncoder interface {
+	// Saves the offset into the input buffer as the location to actually write the calculated value when able.
+	saveOffset(in int)
+
+	// Returns the length of data to reserve for the output of this encoder (eg 4 bytes for a CRC32).
+	reserveLength() int
+
+	// Indicates that all required data is now available to calculate and write the field.
+	// SaveOffset is guaranteed to have been called first. The implementation should write ReserveLength() bytes
+	// of data to the saved offset, based on the data between the saved offset and curOffset.
+	run(curOffset int, buf []byte) error
+}
+
+// dynamicPushEncoder extends the interface of pushEncoder for uses cases where the length of the
+// fields itself is unknown until its value was computed (for instance varint encoded length
+// fields).
+type dynamicPushEncoder interface {
+	pushEncoder
+
+	// Called during pop() to adjust the length of the field.
+	// It should return the difference in bytes between the last computed length and current length.
+	adjustLength(currOffset int) int
+}
diff --git a/vendor/github.com/Shopify/sarama/partitioner.go b/vendor/github.com/Shopify/sarama/partitioner.go
new file mode 100644
index 0000000..6a708e7
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/partitioner.go
@@ -0,0 +1,217 @@
+package sarama
+
+import (
+	"hash"
+	"hash/fnv"
+	"math/rand"
+	"time"
+)
+
+// Partitioner is anything that, given a Kafka message and a number of partitions indexed [0...numPartitions-1],
+// decides to which partition to send the message. RandomPartitioner, RoundRobinPartitioner and HashPartitioner are provided
+// as simple default implementations.
+type Partitioner interface {
+	// Partition takes a message and partition count and chooses a partition
+	Partition(message *ProducerMessage, numPartitions int32) (int32, error)
+
+	// RequiresConsistency indicates to the user of the partitioner whether the
+	// mapping of key->partition is consistent or not. Specifically, if a
+	// partitioner requires consistency then it must be allowed to choose from all
+	// partitions (even ones known to be unavailable), and its choice must be
+	// respected by the caller. The obvious example is the HashPartitioner.
+	RequiresConsistency() bool
+}
+
+// DynamicConsistencyPartitioner can optionally be implemented by Partitioners
+// in order to allow more flexibility than is originally allowed by the
+// RequiresConsistency method in the Partitioner interface. This allows
+// partitioners to require consistency sometimes, but not all times. It's useful
+// for, e.g., the HashPartitioner, which does not require consistency if the
+// message key is nil.
+type DynamicConsistencyPartitioner interface {
+	Partitioner
+
+	// MessageRequiresConsistency is similar to Partitioner.RequiresConsistency,
+	// but takes in the message being partitioned so that the partitioner can
+	// make a per-message determination.
+	MessageRequiresConsistency(message *ProducerMessage) bool
+}
+
+// PartitionerConstructor is the type for a function capable of constructing new Partitioners.
+type PartitionerConstructor func(topic string) Partitioner
+
+type manualPartitioner struct{}
+
+// HashPartitionOption lets you modify default values of the partitioner
+type HashPartitionerOption func(*hashPartitioner)
+
+// WithAbsFirst means that the partitioner handles absolute values
+// in the same way as the reference Java implementation
+func WithAbsFirst() HashPartitionerOption {
+	return func(hp *hashPartitioner) {
+		hp.referenceAbs = true
+	}
+}
+
+// WithCustomHashFunction lets you specify what hash function to use for the partitioning
+func WithCustomHashFunction(hasher func() hash.Hash32) HashPartitionerOption {
+	return func(hp *hashPartitioner) {
+		hp.hasher = hasher()
+	}
+}
+
+// WithCustomFallbackPartitioner lets you specify what HashPartitioner should be used in case a Distribution Key is empty
+func WithCustomFallbackPartitioner(randomHP *hashPartitioner) HashPartitionerOption {
+	return func(hp *hashPartitioner) {
+		hp.random = hp
+	}
+}
+
+// NewManualPartitioner returns a Partitioner which uses the partition manually set in the provided
+// ProducerMessage's Partition field as the partition to produce to.
+func NewManualPartitioner(topic string) Partitioner {
+	return new(manualPartitioner)
+}
+
+func (p *manualPartitioner) Partition(message *ProducerMessage, numPartitions int32) (int32, error) {
+	return message.Partition, nil
+}
+
+func (p *manualPartitioner) RequiresConsistency() bool {
+	return true
+}
+
+type randomPartitioner struct {
+	generator *rand.Rand
+}
+
+// NewRandomPartitioner returns a Partitioner which chooses a random partition each time.
+func NewRandomPartitioner(topic string) Partitioner {
+	p := new(randomPartitioner)
+	p.generator = rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
+	return p
+}
+
+func (p *randomPartitioner) Partition(message *ProducerMessage, numPartitions int32) (int32, error) {
+	return int32(p.generator.Intn(int(numPartitions))), nil
+}
+
+func (p *randomPartitioner) RequiresConsistency() bool {
+	return false
+}
+
+type roundRobinPartitioner struct {
+	partition int32
+}
+
+// NewRoundRobinPartitioner returns a Partitioner which walks through the available partitions one at a time.
+func NewRoundRobinPartitioner(topic string) Partitioner {
+	return &roundRobinPartitioner{}
+}
+
+func (p *roundRobinPartitioner) Partition(message *ProducerMessage, numPartitions int32) (int32, error) {
+	if p.partition >= numPartitions {
+		p.partition = 0
+	}
+	ret := p.partition
+	p.partition++
+	return ret, nil
+}
+
+func (p *roundRobinPartitioner) RequiresConsistency() bool {
+	return false
+}
+
+type hashPartitioner struct {
+	random       Partitioner
+	hasher       hash.Hash32
+	referenceAbs bool
+}
+
+// NewCustomHashPartitioner is a wrapper around NewHashPartitioner, allowing the use of custom hasher.
+// The argument is a function providing the instance, implementing the hash.Hash32 interface. This is to ensure that
+// each partition dispatcher gets its own hasher, to avoid concurrency issues by sharing an instance.
+func NewCustomHashPartitioner(hasher func() hash.Hash32) PartitionerConstructor {
+	return func(topic string) Partitioner {
+		p := new(hashPartitioner)
+		p.random = NewRandomPartitioner(topic)
+		p.hasher = hasher()
+		p.referenceAbs = false
+		return p
+	}
+}
+
+// NewCustomPartitioner creates a default Partitioner but lets you specify the behavior of each component via options
+func NewCustomPartitioner(options ...HashPartitionerOption) PartitionerConstructor {
+	return func(topic string) Partitioner {
+		p := new(hashPartitioner)
+		p.random = NewRandomPartitioner(topic)
+		p.hasher = fnv.New32a()
+		p.referenceAbs = false
+		for _, option := range options {
+			option(p)
+		}
+		return p
+	}
+}
+
+// NewHashPartitioner returns a Partitioner which behaves as follows. If the message's key is nil then a
+// random partition is chosen. Otherwise the FNV-1a hash of the encoded bytes of the message key is used,
+// modulus the number of partitions. This ensures that messages with the same key always end up on the
+// same partition.
+func NewHashPartitioner(topic string) Partitioner {
+	p := new(hashPartitioner)
+	p.random = NewRandomPartitioner(topic)
+	p.hasher = fnv.New32a()
+	p.referenceAbs = false
+	return p
+}
+
+// NewReferenceHashPartitioner is like NewHashPartitioner except that it handles absolute values
+// in the same way as the reference Java implementation. NewHashPartitioner was supposed to do
+// that but it had a mistake and now there are people depending on both behaviours. This will
+// all go away on the next major version bump.
+func NewReferenceHashPartitioner(topic string) Partitioner {
+	p := new(hashPartitioner)
+	p.random = NewRandomPartitioner(topic)
+	p.hasher = fnv.New32a()
+	p.referenceAbs = true
+	return p
+}
+
+func (p *hashPartitioner) Partition(message *ProducerMessage, numPartitions int32) (int32, error) {
+	if message.Key == nil {
+		return p.random.Partition(message, numPartitions)
+	}
+	bytes, err := message.Key.Encode()
+	if err != nil {
+		return -1, err
+	}
+	p.hasher.Reset()
+	_, err = p.hasher.Write(bytes)
+	if err != nil {
+		return -1, err
+	}
+	var partition int32
+	// Turns out we were doing our absolute value in a subtly different way from the upstream
+	// implementation, but now we need to maintain backwards compat for people who started using
+	// the old version; if referenceAbs is set we are compatible with the reference java client
+	// but not past Sarama versions
+	if p.referenceAbs {
+		partition = (int32(p.hasher.Sum32()) & 0x7fffffff) % numPartitions
+	} else {
+		partition = int32(p.hasher.Sum32()) % numPartitions
+		if partition < 0 {
+			partition = -partition
+		}
+	}
+	return partition, nil
+}
+
+func (p *hashPartitioner) RequiresConsistency() bool {
+	return true
+}
+
+func (p *hashPartitioner) MessageRequiresConsistency(message *ProducerMessage) bool {
+	return message.Key != nil
+}
diff --git a/vendor/github.com/Shopify/sarama/prep_encoder.go b/vendor/github.com/Shopify/sarama/prep_encoder.go
new file mode 100644
index 0000000..b633cd1
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/prep_encoder.go
@@ -0,0 +1,153 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math"
+
+	"github.com/rcrowley/go-metrics"
+)
+
+type prepEncoder struct {
+	stack  []pushEncoder
+	length int
+}
+
+// primitives
+
+func (pe *prepEncoder) putInt8(in int8) {
+	pe.length++
+}
+
+func (pe *prepEncoder) putInt16(in int16) {
+	pe.length += 2
+}
+
+func (pe *prepEncoder) putInt32(in int32) {
+	pe.length += 4
+}
+
+func (pe *prepEncoder) putInt64(in int64) {
+	pe.length += 8
+}
+
+func (pe *prepEncoder) putVarint(in int64) {
+	var buf [binary.MaxVarintLen64]byte
+	pe.length += binary.PutVarint(buf[:], in)
+}
+
+func (pe *prepEncoder) putArrayLength(in int) error {
+	if in > math.MaxInt32 {
+		return PacketEncodingError{fmt.Sprintf("array too long (%d)", in)}
+	}
+	pe.length += 4
+	return nil
+}
+
+func (pe *prepEncoder) putBool(in bool) {
+	pe.length++
+}
+
+// arrays
+
+func (pe *prepEncoder) putBytes(in []byte) error {
+	pe.length += 4
+	if in == nil {
+		return nil
+	}
+	return pe.putRawBytes(in)
+}
+
+func (pe *prepEncoder) putVarintBytes(in []byte) error {
+	if in == nil {
+		pe.putVarint(-1)
+		return nil
+	}
+	pe.putVarint(int64(len(in)))
+	return pe.putRawBytes(in)
+}
+
+func (pe *prepEncoder) putRawBytes(in []byte) error {
+	if len(in) > math.MaxInt32 {
+		return PacketEncodingError{fmt.Sprintf("byteslice too long (%d)", len(in))}
+	}
+	pe.length += len(in)
+	return nil
+}
+
+func (pe *prepEncoder) putNullableString(in *string) error {
+	if in == nil {
+		pe.length += 2
+		return nil
+	}
+	return pe.putString(*in)
+}
+
+func (pe *prepEncoder) putString(in string) error {
+	pe.length += 2
+	if len(in) > math.MaxInt16 {
+		return PacketEncodingError{fmt.Sprintf("string too long (%d)", len(in))}
+	}
+	pe.length += len(in)
+	return nil
+}
+
+func (pe *prepEncoder) putStringArray(in []string) error {
+	err := pe.putArrayLength(len(in))
+	if err != nil {
+		return err
+	}
+
+	for _, str := range in {
+		if err := pe.putString(str); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (pe *prepEncoder) putInt32Array(in []int32) error {
+	err := pe.putArrayLength(len(in))
+	if err != nil {
+		return err
+	}
+	pe.length += 4 * len(in)
+	return nil
+}
+
+func (pe *prepEncoder) putInt64Array(in []int64) error {
+	err := pe.putArrayLength(len(in))
+	if err != nil {
+		return err
+	}
+	pe.length += 8 * len(in)
+	return nil
+}
+
+func (pe *prepEncoder) offset() int {
+	return pe.length
+}
+
+// stackable
+
+func (pe *prepEncoder) push(in pushEncoder) {
+	in.saveOffset(pe.length)
+	pe.length += in.reserveLength()
+	pe.stack = append(pe.stack, in)
+}
+
+func (pe *prepEncoder) pop() error {
+	in := pe.stack[len(pe.stack)-1]
+	pe.stack = pe.stack[:len(pe.stack)-1]
+	if dpe, ok := in.(dynamicPushEncoder); ok {
+		pe.length += dpe.adjustLength(pe.length)
+	}
+
+	return nil
+}
+
+// we do not record metrics during the prep encoder pass
+func (pe *prepEncoder) metricRegistry() metrics.Registry {
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/produce_request.go b/vendor/github.com/Shopify/sarama/produce_request.go
new file mode 100644
index 0000000..0c755d0
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/produce_request.go
@@ -0,0 +1,252 @@
+package sarama
+
+import "github.com/rcrowley/go-metrics"
+
+// RequiredAcks is used in Produce Requests to tell the broker how many replica acknowledgements
+// it must see before responding. Any of the constants defined here are valid. On broker versions
+// prior to 0.8.2.0 any other positive int16 is also valid (the broker will wait for that many
+// acknowledgements) but in 0.8.2.0 and later this will raise an exception (it has been replaced
+// by setting the `min.isr` value in the brokers configuration).
+type RequiredAcks int16
+
+const (
+	// NoResponse doesn't send any response, the TCP ACK is all you get.
+	NoResponse RequiredAcks = 0
+	// WaitForLocal waits for only the local commit to succeed before responding.
+	WaitForLocal RequiredAcks = 1
+	// WaitForAll waits for all in-sync replicas to commit before responding.
+	// The minimum number of in-sync replicas is configured on the broker via
+	// the `min.insync.replicas` configuration key.
+	WaitForAll RequiredAcks = -1
+)
+
+type ProduceRequest struct {
+	TransactionalID *string
+	RequiredAcks    RequiredAcks
+	Timeout         int32
+	Version         int16 // v1 requires Kafka 0.9, v2 requires Kafka 0.10, v3 requires Kafka 0.11
+	records         map[string]map[int32]Records
+}
+
+func updateMsgSetMetrics(msgSet *MessageSet, compressionRatioMetric metrics.Histogram,
+	topicCompressionRatioMetric metrics.Histogram) int64 {
+	var topicRecordCount int64
+	for _, messageBlock := range msgSet.Messages {
+		// Is this a fake "message" wrapping real messages?
+		if messageBlock.Msg.Set != nil {
+			topicRecordCount += int64(len(messageBlock.Msg.Set.Messages))
+		} else {
+			// A single uncompressed message
+			topicRecordCount++
+		}
+		// Better be safe than sorry when computing the compression ratio
+		if messageBlock.Msg.compressedSize != 0 {
+			compressionRatio := float64(len(messageBlock.Msg.Value)) /
+				float64(messageBlock.Msg.compressedSize)
+			// Histogram do not support decimal values, let's multiple it by 100 for better precision
+			intCompressionRatio := int64(100 * compressionRatio)
+			compressionRatioMetric.Update(intCompressionRatio)
+			topicCompressionRatioMetric.Update(intCompressionRatio)
+		}
+	}
+	return topicRecordCount
+}
+
+func updateBatchMetrics(recordBatch *RecordBatch, compressionRatioMetric metrics.Histogram,
+	topicCompressionRatioMetric metrics.Histogram) int64 {
+	if recordBatch.compressedRecords != nil {
+		compressionRatio := int64(float64(recordBatch.recordsLen) / float64(len(recordBatch.compressedRecords)) * 100)
+		compressionRatioMetric.Update(compressionRatio)
+		topicCompressionRatioMetric.Update(compressionRatio)
+	}
+
+	return int64(len(recordBatch.Records))
+}
+
+func (r *ProduceRequest) encode(pe packetEncoder) error {
+	if r.Version >= 3 {
+		if err := pe.putNullableString(r.TransactionalID); err != nil {
+			return err
+		}
+	}
+	pe.putInt16(int16(r.RequiredAcks))
+	pe.putInt32(r.Timeout)
+	metricRegistry := pe.metricRegistry()
+	var batchSizeMetric metrics.Histogram
+	var compressionRatioMetric metrics.Histogram
+	if metricRegistry != nil {
+		batchSizeMetric = getOrRegisterHistogram("batch-size", metricRegistry)
+		compressionRatioMetric = getOrRegisterHistogram("compression-ratio", metricRegistry)
+	}
+	totalRecordCount := int64(0)
+
+	err := pe.putArrayLength(len(r.records))
+	if err != nil {
+		return err
+	}
+
+	for topic, partitions := range r.records {
+		err = pe.putString(topic)
+		if err != nil {
+			return err
+		}
+		err = pe.putArrayLength(len(partitions))
+		if err != nil {
+			return err
+		}
+		topicRecordCount := int64(0)
+		var topicCompressionRatioMetric metrics.Histogram
+		if metricRegistry != nil {
+			topicCompressionRatioMetric = getOrRegisterTopicHistogram("compression-ratio", topic, metricRegistry)
+		}
+		for id, records := range partitions {
+			startOffset := pe.offset()
+			pe.putInt32(id)
+			pe.push(&lengthField{})
+			err = records.encode(pe)
+			if err != nil {
+				return err
+			}
+			err = pe.pop()
+			if err != nil {
+				return err
+			}
+			if metricRegistry != nil {
+				if r.Version >= 3 {
+					topicRecordCount += updateBatchMetrics(records.RecordBatch, compressionRatioMetric, topicCompressionRatioMetric)
+				} else {
+					topicRecordCount += updateMsgSetMetrics(records.MsgSet, compressionRatioMetric, topicCompressionRatioMetric)
+				}
+				batchSize := int64(pe.offset() - startOffset)
+				batchSizeMetric.Update(batchSize)
+				getOrRegisterTopicHistogram("batch-size", topic, metricRegistry).Update(batchSize)
+			}
+		}
+		if topicRecordCount > 0 {
+			getOrRegisterTopicMeter("record-send-rate", topic, metricRegistry).Mark(topicRecordCount)
+			getOrRegisterTopicHistogram("records-per-request", topic, metricRegistry).Update(topicRecordCount)
+			totalRecordCount += topicRecordCount
+		}
+	}
+	if totalRecordCount > 0 {
+		metrics.GetOrRegisterMeter("record-send-rate", metricRegistry).Mark(totalRecordCount)
+		getOrRegisterHistogram("records-per-request", metricRegistry).Update(totalRecordCount)
+	}
+
+	return nil
+}
+
+func (r *ProduceRequest) decode(pd packetDecoder, version int16) error {
+	r.Version = version
+
+	if version >= 3 {
+		id, err := pd.getNullableString()
+		if err != nil {
+			return err
+		}
+		r.TransactionalID = id
+	}
+	requiredAcks, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	r.RequiredAcks = RequiredAcks(requiredAcks)
+	if r.Timeout, err = pd.getInt32(); err != nil {
+		return err
+	}
+	topicCount, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if topicCount == 0 {
+		return nil
+	}
+
+	r.records = make(map[string]map[int32]Records)
+	for i := 0; i < topicCount; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		partitionCount, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+		r.records[topic] = make(map[int32]Records)
+
+		for j := 0; j < partitionCount; j++ {
+			partition, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+			size, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+			recordsDecoder, err := pd.getSubset(int(size))
+			if err != nil {
+				return err
+			}
+			var records Records
+			if err := records.decode(recordsDecoder); err != nil {
+				return err
+			}
+			r.records[topic][partition] = records
+		}
+	}
+
+	return nil
+}
+
+func (r *ProduceRequest) key() int16 {
+	return 0
+}
+
+func (r *ProduceRequest) version() int16 {
+	return r.Version
+}
+
+func (r *ProduceRequest) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_9_0_0
+	case 2:
+		return V0_10_0_0
+	case 3:
+		return V0_11_0_0
+	default:
+		return MinVersion
+	}
+}
+
+func (r *ProduceRequest) ensureRecords(topic string, partition int32) {
+	if r.records == nil {
+		r.records = make(map[string]map[int32]Records)
+	}
+
+	if r.records[topic] == nil {
+		r.records[topic] = make(map[int32]Records)
+	}
+}
+
+func (r *ProduceRequest) AddMessage(topic string, partition int32, msg *Message) {
+	r.ensureRecords(topic, partition)
+	set := r.records[topic][partition].MsgSet
+
+	if set == nil {
+		set = new(MessageSet)
+		r.records[topic][partition] = newLegacyRecords(set)
+	}
+
+	set.addMessage(msg)
+}
+
+func (r *ProduceRequest) AddSet(topic string, partition int32, set *MessageSet) {
+	r.ensureRecords(topic, partition)
+	r.records[topic][partition] = newLegacyRecords(set)
+}
+
+func (r *ProduceRequest) AddBatch(topic string, partition int32, batch *RecordBatch) {
+	r.ensureRecords(topic, partition)
+	r.records[topic][partition] = newDefaultRecords(batch)
+}
diff --git a/vendor/github.com/Shopify/sarama/produce_response.go b/vendor/github.com/Shopify/sarama/produce_response.go
new file mode 100644
index 0000000..4c5cd35
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/produce_response.go
@@ -0,0 +1,189 @@
+package sarama
+
+import (
+	"fmt"
+	"time"
+)
+
+type ProduceResponseBlock struct {
+	Err    KError
+	Offset int64
+	// only provided if Version >= 2 and the broker is configured with `LogAppendTime`
+	Timestamp time.Time
+}
+
+func (b *ProduceResponseBlock) decode(pd packetDecoder, version int16) (err error) {
+	tmp, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	b.Err = KError(tmp)
+
+	b.Offset, err = pd.getInt64()
+	if err != nil {
+		return err
+	}
+
+	if version >= 2 {
+		if millis, err := pd.getInt64(); err != nil {
+			return err
+		} else if millis != -1 {
+			b.Timestamp = time.Unix(millis/1000, (millis%1000)*int64(time.Millisecond))
+		}
+	}
+
+	return nil
+}
+
+func (b *ProduceResponseBlock) encode(pe packetEncoder, version int16) (err error) {
+	pe.putInt16(int16(b.Err))
+	pe.putInt64(b.Offset)
+
+	if version >= 2 {
+		timestamp := int64(-1)
+		if !b.Timestamp.Before(time.Unix(0, 0)) {
+			timestamp = b.Timestamp.UnixNano() / int64(time.Millisecond)
+		} else if !b.Timestamp.IsZero() {
+			return PacketEncodingError{fmt.Sprintf("invalid timestamp (%v)", b.Timestamp)}
+		}
+		pe.putInt64(timestamp)
+	}
+
+	return nil
+}
+
+type ProduceResponse struct {
+	Blocks       map[string]map[int32]*ProduceResponseBlock
+	Version      int16
+	ThrottleTime time.Duration // only provided if Version >= 1
+}
+
+func (r *ProduceResponse) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+
+	numTopics, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	r.Blocks = make(map[string]map[int32]*ProduceResponseBlock, numTopics)
+	for i := 0; i < numTopics; i++ {
+		name, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		numBlocks, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+
+		r.Blocks[name] = make(map[int32]*ProduceResponseBlock, numBlocks)
+
+		for j := 0; j < numBlocks; j++ {
+			id, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+
+			block := new(ProduceResponseBlock)
+			err = block.decode(pd, version)
+			if err != nil {
+				return err
+			}
+			r.Blocks[name][id] = block
+		}
+	}
+
+	if r.Version >= 1 {
+		millis, err := pd.getInt32()
+		if err != nil {
+			return err
+		}
+
+		r.ThrottleTime = time.Duration(millis) * time.Millisecond
+	}
+
+	return nil
+}
+
+func (r *ProduceResponse) encode(pe packetEncoder) error {
+	err := pe.putArrayLength(len(r.Blocks))
+	if err != nil {
+		return err
+	}
+	for topic, partitions := range r.Blocks {
+		err = pe.putString(topic)
+		if err != nil {
+			return err
+		}
+		err = pe.putArrayLength(len(partitions))
+		if err != nil {
+			return err
+		}
+		for id, prb := range partitions {
+			pe.putInt32(id)
+			err = prb.encode(pe, r.Version)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	if r.Version >= 1 {
+		pe.putInt32(int32(r.ThrottleTime / time.Millisecond))
+	}
+	return nil
+}
+
+func (r *ProduceResponse) key() int16 {
+	return 0
+}
+
+func (r *ProduceResponse) version() int16 {
+	return r.Version
+}
+
+func (r *ProduceResponse) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_9_0_0
+	case 2:
+		return V0_10_0_0
+	case 3:
+		return V0_11_0_0
+	default:
+		return MinVersion
+	}
+}
+
+func (r *ProduceResponse) GetBlock(topic string, partition int32) *ProduceResponseBlock {
+	if r.Blocks == nil {
+		return nil
+	}
+
+	if r.Blocks[topic] == nil {
+		return nil
+	}
+
+	return r.Blocks[topic][partition]
+}
+
+// Testing API
+
+func (r *ProduceResponse) AddTopicPartition(topic string, partition int32, err KError) {
+	if r.Blocks == nil {
+		r.Blocks = make(map[string]map[int32]*ProduceResponseBlock)
+	}
+	byTopic, ok := r.Blocks[topic]
+	if !ok {
+		byTopic = make(map[int32]*ProduceResponseBlock)
+		r.Blocks[topic] = byTopic
+	}
+	block := &ProduceResponseBlock{
+		Err: err,
+	}
+	if r.Version >= 2 {
+		block.Timestamp = time.Now()
+	}
+	byTopic[partition] = block
+}
diff --git a/vendor/github.com/Shopify/sarama/produce_set.go b/vendor/github.com/Shopify/sarama/produce_set.go
new file mode 100644
index 0000000..b684aa4
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/produce_set.go
@@ -0,0 +1,259 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"errors"
+	"time"
+)
+
+type partitionSet struct {
+	msgs          []*ProducerMessage
+	recordsToSend Records
+	bufferBytes   int
+}
+
+type produceSet struct {
+	parent *asyncProducer
+	msgs   map[string]map[int32]*partitionSet
+
+	bufferBytes int
+	bufferCount int
+}
+
+func newProduceSet(parent *asyncProducer) *produceSet {
+	return &produceSet{
+		msgs:   make(map[string]map[int32]*partitionSet),
+		parent: parent,
+	}
+}
+
+func (ps *produceSet) add(msg *ProducerMessage) error {
+	var err error
+	var key, val []byte
+
+	if msg.Key != nil {
+		if key, err = msg.Key.Encode(); err != nil {
+			return err
+		}
+	}
+
+	if msg.Value != nil {
+		if val, err = msg.Value.Encode(); err != nil {
+			return err
+		}
+	}
+
+	timestamp := msg.Timestamp
+	if timestamp.IsZero() {
+		timestamp = time.Now()
+	}
+	timestamp = timestamp.Truncate(time.Millisecond)
+
+	partitions := ps.msgs[msg.Topic]
+	if partitions == nil {
+		partitions = make(map[int32]*partitionSet)
+		ps.msgs[msg.Topic] = partitions
+	}
+
+	var size int
+
+	set := partitions[msg.Partition]
+	if set == nil {
+		if ps.parent.conf.Version.IsAtLeast(V0_11_0_0) {
+			batch := &RecordBatch{
+				FirstTimestamp:   timestamp,
+				Version:          2,
+				Codec:            ps.parent.conf.Producer.Compression,
+				CompressionLevel: ps.parent.conf.Producer.CompressionLevel,
+				ProducerID:       ps.parent.txnmgr.producerID,
+				ProducerEpoch:    ps.parent.txnmgr.producerEpoch,
+			}
+			if ps.parent.conf.Producer.Idempotent {
+				batch.FirstSequence = msg.sequenceNumber
+			}
+			set = &partitionSet{recordsToSend: newDefaultRecords(batch)}
+			size = recordBatchOverhead
+		} else {
+			set = &partitionSet{recordsToSend: newLegacyRecords(new(MessageSet))}
+		}
+		partitions[msg.Partition] = set
+	}
+	set.msgs = append(set.msgs, msg)
+
+	if ps.parent.conf.Version.IsAtLeast(V0_11_0_0) {
+		if ps.parent.conf.Producer.Idempotent && msg.sequenceNumber < set.recordsToSend.RecordBatch.FirstSequence {
+			return errors.New("assertion failed: message out of sequence added to a batch")
+		}
+		// We are being conservative here to avoid having to prep encode the record
+		size += maximumRecordOverhead
+		rec := &Record{
+			Key:            key,
+			Value:          val,
+			TimestampDelta: timestamp.Sub(set.recordsToSend.RecordBatch.FirstTimestamp),
+		}
+		size += len(key) + len(val)
+		if len(msg.Headers) > 0 {
+			rec.Headers = make([]*RecordHeader, len(msg.Headers))
+			for i := range msg.Headers {
+				rec.Headers[i] = &msg.Headers[i]
+				size += len(rec.Headers[i].Key) + len(rec.Headers[i].Value) + 2*binary.MaxVarintLen32
+			}
+		}
+		set.recordsToSend.RecordBatch.addRecord(rec)
+	} else {
+		msgToSend := &Message{Codec: CompressionNone, Key: key, Value: val}
+		if ps.parent.conf.Version.IsAtLeast(V0_10_0_0) {
+			msgToSend.Timestamp = timestamp
+			msgToSend.Version = 1
+		}
+		set.recordsToSend.MsgSet.addMessage(msgToSend)
+		size = producerMessageOverhead + len(key) + len(val)
+	}
+
+	set.bufferBytes += size
+	ps.bufferBytes += size
+	ps.bufferCount++
+
+	return nil
+}
+
+func (ps *produceSet) buildRequest() *ProduceRequest {
+	req := &ProduceRequest{
+		RequiredAcks: ps.parent.conf.Producer.RequiredAcks,
+		Timeout:      int32(ps.parent.conf.Producer.Timeout / time.Millisecond),
+	}
+	if ps.parent.conf.Version.IsAtLeast(V0_10_0_0) {
+		req.Version = 2
+	}
+	if ps.parent.conf.Version.IsAtLeast(V0_11_0_0) {
+		req.Version = 3
+	}
+
+	for topic, partitionSets := range ps.msgs {
+		for partition, set := range partitionSets {
+			if req.Version >= 3 {
+				// If the API version we're hitting is 3 or greater, we need to calculate
+				// offsets for each record in the batch relative to FirstOffset.
+				// Additionally, we must set LastOffsetDelta to the value of the last offset
+				// in the batch. Since the OffsetDelta of the first record is 0, we know that the
+				// final record of any batch will have an offset of (# of records in batch) - 1.
+				// (See https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol#AGuideToTheKafkaProtocol-Messagesets
+				//  under the RecordBatch section for details.)
+				rb := set.recordsToSend.RecordBatch
+				if len(rb.Records) > 0 {
+					rb.LastOffsetDelta = int32(len(rb.Records) - 1)
+					for i, record := range rb.Records {
+						record.OffsetDelta = int64(i)
+					}
+				}
+				req.AddBatch(topic, partition, rb)
+				continue
+			}
+			if ps.parent.conf.Producer.Compression == CompressionNone {
+				req.AddSet(topic, partition, set.recordsToSend.MsgSet)
+			} else {
+				// When compression is enabled, the entire set for each partition is compressed
+				// and sent as the payload of a single fake "message" with the appropriate codec
+				// set and no key. When the server sees a message with a compression codec, it
+				// decompresses the payload and treats the result as its message set.
+
+				if ps.parent.conf.Version.IsAtLeast(V0_10_0_0) {
+					// If our version is 0.10 or later, assign relative offsets
+					// to the inner messages. This lets the broker avoid
+					// recompressing the message set.
+					// (See https://cwiki.apache.org/confluence/display/KAFKA/KIP-31+-+Move+to+relative+offsets+in+compressed+message+sets
+					// for details on relative offsets.)
+					for i, msg := range set.recordsToSend.MsgSet.Messages {
+						msg.Offset = int64(i)
+					}
+				}
+				payload, err := encode(set.recordsToSend.MsgSet, ps.parent.conf.MetricRegistry)
+				if err != nil {
+					Logger.Println(err) // if this happens, it's basically our fault.
+					panic(err)
+				}
+				compMsg := &Message{
+					Codec:            ps.parent.conf.Producer.Compression,
+					CompressionLevel: ps.parent.conf.Producer.CompressionLevel,
+					Key:              nil,
+					Value:            payload,
+					Set:              set.recordsToSend.MsgSet, // Provide the underlying message set for accurate metrics
+				}
+				if ps.parent.conf.Version.IsAtLeast(V0_10_0_0) {
+					compMsg.Version = 1
+					compMsg.Timestamp = set.recordsToSend.MsgSet.Messages[0].Msg.Timestamp
+				}
+				req.AddMessage(topic, partition, compMsg)
+			}
+		}
+	}
+
+	return req
+}
+
+func (ps *produceSet) eachPartition(cb func(topic string, partition int32, pSet *partitionSet)) {
+	for topic, partitionSet := range ps.msgs {
+		for partition, set := range partitionSet {
+			cb(topic, partition, set)
+		}
+	}
+}
+
+func (ps *produceSet) dropPartition(topic string, partition int32) []*ProducerMessage {
+	if ps.msgs[topic] == nil {
+		return nil
+	}
+	set := ps.msgs[topic][partition]
+	if set == nil {
+		return nil
+	}
+	ps.bufferBytes -= set.bufferBytes
+	ps.bufferCount -= len(set.msgs)
+	delete(ps.msgs[topic], partition)
+	return set.msgs
+}
+
+func (ps *produceSet) wouldOverflow(msg *ProducerMessage) bool {
+	version := 1
+	if ps.parent.conf.Version.IsAtLeast(V0_11_0_0) {
+		version = 2
+	}
+
+	switch {
+	// Would we overflow our maximum possible size-on-the-wire? 10KiB is arbitrary overhead for safety.
+	case ps.bufferBytes+msg.byteSize(version) >= int(MaxRequestSize-(10*1024)):
+		return true
+	// Would we overflow the size-limit of a message-batch for this partition?
+	case ps.msgs[msg.Topic] != nil && ps.msgs[msg.Topic][msg.Partition] != nil &&
+		ps.msgs[msg.Topic][msg.Partition].bufferBytes+msg.byteSize(version) >= ps.parent.conf.Producer.MaxMessageBytes:
+		return true
+	// Would we overflow simply in number of messages?
+	case ps.parent.conf.Producer.Flush.MaxMessages > 0 && ps.bufferCount >= ps.parent.conf.Producer.Flush.MaxMessages:
+		return true
+	default:
+		return false
+	}
+}
+
+func (ps *produceSet) readyToFlush() bool {
+	switch {
+	// If we don't have any messages, nothing else matters
+	case ps.empty():
+		return false
+	// If all three config values are 0, we always flush as-fast-as-possible
+	case ps.parent.conf.Producer.Flush.Frequency == 0 && ps.parent.conf.Producer.Flush.Bytes == 0 && ps.parent.conf.Producer.Flush.Messages == 0:
+		return true
+	// If we've passed the message trigger-point
+	case ps.parent.conf.Producer.Flush.Messages > 0 && ps.bufferCount >= ps.parent.conf.Producer.Flush.Messages:
+		return true
+	// If we've passed the byte trigger-point
+	case ps.parent.conf.Producer.Flush.Bytes > 0 && ps.bufferBytes >= ps.parent.conf.Producer.Flush.Bytes:
+		return true
+	default:
+		return false
+	}
+}
+
+func (ps *produceSet) empty() bool {
+	return ps.bufferCount == 0
+}
diff --git a/vendor/github.com/Shopify/sarama/real_decoder.go b/vendor/github.com/Shopify/sarama/real_decoder.go
new file mode 100644
index 0000000..085cbb3
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/real_decoder.go
@@ -0,0 +1,332 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"math"
+)
+
+var errInvalidArrayLength = PacketDecodingError{"invalid array length"}
+var errInvalidByteSliceLength = PacketDecodingError{"invalid byteslice length"}
+var errInvalidByteSliceLengthType = PacketDecodingError{"invalid byteslice length type"}
+var errInvalidStringLength = PacketDecodingError{"invalid string length"}
+var errInvalidSubsetSize = PacketDecodingError{"invalid subset size"}
+var errVarintOverflow = PacketDecodingError{"varint overflow"}
+var errInvalidBool = PacketDecodingError{"invalid bool"}
+
+type realDecoder struct {
+	raw   []byte
+	off   int
+	stack []pushDecoder
+}
+
+// primitives
+
+func (rd *realDecoder) getInt8() (int8, error) {
+	if rd.remaining() < 1 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	tmp := int8(rd.raw[rd.off])
+	rd.off++
+	return tmp, nil
+}
+
+func (rd *realDecoder) getInt16() (int16, error) {
+	if rd.remaining() < 2 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	tmp := int16(binary.BigEndian.Uint16(rd.raw[rd.off:]))
+	rd.off += 2
+	return tmp, nil
+}
+
+func (rd *realDecoder) getInt32() (int32, error) {
+	if rd.remaining() < 4 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	tmp := int32(binary.BigEndian.Uint32(rd.raw[rd.off:]))
+	rd.off += 4
+	return tmp, nil
+}
+
+func (rd *realDecoder) getInt64() (int64, error) {
+	if rd.remaining() < 8 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	tmp := int64(binary.BigEndian.Uint64(rd.raw[rd.off:]))
+	rd.off += 8
+	return tmp, nil
+}
+
+func (rd *realDecoder) getVarint() (int64, error) {
+	tmp, n := binary.Varint(rd.raw[rd.off:])
+	if n == 0 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	if n < 0 {
+		rd.off -= n
+		return -1, errVarintOverflow
+	}
+	rd.off += n
+	return tmp, nil
+}
+
+func (rd *realDecoder) getArrayLength() (int, error) {
+	if rd.remaining() < 4 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	tmp := int(int32(binary.BigEndian.Uint32(rd.raw[rd.off:])))
+	rd.off += 4
+	if tmp > rd.remaining() {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	} else if tmp > 2*math.MaxUint16 {
+		return -1, errInvalidArrayLength
+	}
+	return tmp, nil
+}
+
+func (rd *realDecoder) getBool() (bool, error) {
+	b, err := rd.getInt8()
+	if err != nil || b == 0 {
+		return false, err
+	}
+	if b != 1 {
+		return false, errInvalidBool
+	}
+	return true, nil
+}
+
+// collections
+
+func (rd *realDecoder) getBytes() ([]byte, error) {
+	tmp, err := rd.getInt32()
+	if err != nil {
+		return nil, err
+	}
+	if tmp == -1 {
+		return nil, nil
+	}
+
+	return rd.getRawBytes(int(tmp))
+}
+
+func (rd *realDecoder) getVarintBytes() ([]byte, error) {
+	tmp, err := rd.getVarint()
+	if err != nil {
+		return nil, err
+	}
+	if tmp == -1 {
+		return nil, nil
+	}
+
+	return rd.getRawBytes(int(tmp))
+}
+
+func (rd *realDecoder) getStringLength() (int, error) {
+	length, err := rd.getInt16()
+	if err != nil {
+		return 0, err
+	}
+
+	n := int(length)
+
+	switch {
+	case n < -1:
+		return 0, errInvalidStringLength
+	case n > rd.remaining():
+		rd.off = len(rd.raw)
+		return 0, ErrInsufficientData
+	}
+
+	return n, nil
+}
+
+func (rd *realDecoder) getString() (string, error) {
+	n, err := rd.getStringLength()
+	if err != nil || n == -1 {
+		return "", err
+	}
+
+	tmpStr := string(rd.raw[rd.off : rd.off+n])
+	rd.off += n
+	return tmpStr, nil
+}
+
+func (rd *realDecoder) getNullableString() (*string, error) {
+	n, err := rd.getStringLength()
+	if err != nil || n == -1 {
+		return nil, err
+	}
+
+	tmpStr := string(rd.raw[rd.off : rd.off+n])
+	rd.off += n
+	return &tmpStr, err
+}
+
+func (rd *realDecoder) getInt32Array() ([]int32, error) {
+	if rd.remaining() < 4 {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+	n := int(binary.BigEndian.Uint32(rd.raw[rd.off:]))
+	rd.off += 4
+
+	if rd.remaining() < 4*n {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+
+	if n == 0 {
+		return nil, nil
+	}
+
+	if n < 0 {
+		return nil, errInvalidArrayLength
+	}
+
+	ret := make([]int32, n)
+	for i := range ret {
+		ret[i] = int32(binary.BigEndian.Uint32(rd.raw[rd.off:]))
+		rd.off += 4
+	}
+	return ret, nil
+}
+
+func (rd *realDecoder) getInt64Array() ([]int64, error) {
+	if rd.remaining() < 4 {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+	n := int(binary.BigEndian.Uint32(rd.raw[rd.off:]))
+	rd.off += 4
+
+	if rd.remaining() < 8*n {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+
+	if n == 0 {
+		return nil, nil
+	}
+
+	if n < 0 {
+		return nil, errInvalidArrayLength
+	}
+
+	ret := make([]int64, n)
+	for i := range ret {
+		ret[i] = int64(binary.BigEndian.Uint64(rd.raw[rd.off:]))
+		rd.off += 8
+	}
+	return ret, nil
+}
+
+func (rd *realDecoder) getStringArray() ([]string, error) {
+	if rd.remaining() < 4 {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+	n := int(binary.BigEndian.Uint32(rd.raw[rd.off:]))
+	rd.off += 4
+
+	if n == 0 {
+		return nil, nil
+	}
+
+	if n < 0 {
+		return nil, errInvalidArrayLength
+	}
+
+	ret := make([]string, n)
+	for i := range ret {
+		str, err := rd.getString()
+		if err != nil {
+			return nil, err
+		}
+
+		ret[i] = str
+	}
+	return ret, nil
+}
+
+// subsets
+
+func (rd *realDecoder) remaining() int {
+	return len(rd.raw) - rd.off
+}
+
+func (rd *realDecoder) getSubset(length int) (packetDecoder, error) {
+	buf, err := rd.getRawBytes(length)
+	if err != nil {
+		return nil, err
+	}
+	return &realDecoder{raw: buf}, nil
+}
+
+func (rd *realDecoder) getRawBytes(length int) ([]byte, error) {
+	if length < 0 {
+		return nil, errInvalidByteSliceLength
+	} else if length > rd.remaining() {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+
+	start := rd.off
+	rd.off += length
+	return rd.raw[start:rd.off], nil
+}
+
+func (rd *realDecoder) peek(offset, length int) (packetDecoder, error) {
+	if rd.remaining() < offset+length {
+		return nil, ErrInsufficientData
+	}
+	off := rd.off + offset
+	return &realDecoder{raw: rd.raw[off : off+length]}, nil
+}
+
+func (rd *realDecoder) peekInt8(offset int) (int8, error) {
+	const byteLen = 1
+	if rd.remaining() < offset+byteLen {
+		return -1, ErrInsufficientData
+	}
+	return int8(rd.raw[rd.off+offset]), nil
+}
+
+// stacks
+
+func (rd *realDecoder) push(in pushDecoder) error {
+	in.saveOffset(rd.off)
+
+	var reserve int
+	if dpd, ok := in.(dynamicPushDecoder); ok {
+		if err := dpd.decode(rd); err != nil {
+			return err
+		}
+	} else {
+		reserve = in.reserveLength()
+		if rd.remaining() < reserve {
+			rd.off = len(rd.raw)
+			return ErrInsufficientData
+		}
+	}
+
+	rd.stack = append(rd.stack, in)
+
+	rd.off += reserve
+
+	return nil
+}
+
+func (rd *realDecoder) pop() error {
+	// this is go's ugly pop pattern (the inverse of append)
+	in := rd.stack[len(rd.stack)-1]
+	rd.stack = rd.stack[:len(rd.stack)-1]
+
+	return in.check(rd.off, rd.raw)
+}
diff --git a/vendor/github.com/Shopify/sarama/real_encoder.go b/vendor/github.com/Shopify/sarama/real_encoder.go
new file mode 100644
index 0000000..3c75387
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/real_encoder.go
@@ -0,0 +1,156 @@
+package sarama
+
+import (
+	"encoding/binary"
+
+	"github.com/rcrowley/go-metrics"
+)
+
+type realEncoder struct {
+	raw      []byte
+	off      int
+	stack    []pushEncoder
+	registry metrics.Registry
+}
+
+// primitives
+
+func (re *realEncoder) putInt8(in int8) {
+	re.raw[re.off] = byte(in)
+	re.off++
+}
+
+func (re *realEncoder) putInt16(in int16) {
+	binary.BigEndian.PutUint16(re.raw[re.off:], uint16(in))
+	re.off += 2
+}
+
+func (re *realEncoder) putInt32(in int32) {
+	binary.BigEndian.PutUint32(re.raw[re.off:], uint32(in))
+	re.off += 4
+}
+
+func (re *realEncoder) putInt64(in int64) {
+	binary.BigEndian.PutUint64(re.raw[re.off:], uint64(in))
+	re.off += 8
+}
+
+func (re *realEncoder) putVarint(in int64) {
+	re.off += binary.PutVarint(re.raw[re.off:], in)
+}
+
+func (re *realEncoder) putArrayLength(in int) error {
+	re.putInt32(int32(in))
+	return nil
+}
+
+func (re *realEncoder) putBool(in bool) {
+	if in {
+		re.putInt8(1)
+		return
+	}
+	re.putInt8(0)
+}
+
+// collection
+
+func (re *realEncoder) putRawBytes(in []byte) error {
+	copy(re.raw[re.off:], in)
+	re.off += len(in)
+	return nil
+}
+
+func (re *realEncoder) putBytes(in []byte) error {
+	if in == nil {
+		re.putInt32(-1)
+		return nil
+	}
+	re.putInt32(int32(len(in)))
+	return re.putRawBytes(in)
+}
+
+func (re *realEncoder) putVarintBytes(in []byte) error {
+	if in == nil {
+		re.putVarint(-1)
+		return nil
+	}
+	re.putVarint(int64(len(in)))
+	return re.putRawBytes(in)
+}
+
+func (re *realEncoder) putString(in string) error {
+	re.putInt16(int16(len(in)))
+	copy(re.raw[re.off:], in)
+	re.off += len(in)
+	return nil
+}
+
+func (re *realEncoder) putNullableString(in *string) error {
+	if in == nil {
+		re.putInt16(-1)
+		return nil
+	}
+	return re.putString(*in)
+}
+
+func (re *realEncoder) putStringArray(in []string) error {
+	err := re.putArrayLength(len(in))
+	if err != nil {
+		return err
+	}
+
+	for _, val := range in {
+		if err := re.putString(val); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (re *realEncoder) putInt32Array(in []int32) error {
+	err := re.putArrayLength(len(in))
+	if err != nil {
+		return err
+	}
+	for _, val := range in {
+		re.putInt32(val)
+	}
+	return nil
+}
+
+func (re *realEncoder) putInt64Array(in []int64) error {
+	err := re.putArrayLength(len(in))
+	if err != nil {
+		return err
+	}
+	for _, val := range in {
+		re.putInt64(val)
+	}
+	return nil
+}
+
+func (re *realEncoder) offset() int {
+	return re.off
+}
+
+// stacks
+
+func (re *realEncoder) push(in pushEncoder) {
+	in.saveOffset(re.off)
+	re.off += in.reserveLength()
+	re.stack = append(re.stack, in)
+}
+
+func (re *realEncoder) pop() error {
+	// this is go's ugly pop pattern (the inverse of append)
+	in := re.stack[len(re.stack)-1]
+	re.stack = re.stack[:len(re.stack)-1]
+
+	return in.run(re.off, re.raw)
+}
+
+// we do record metrics during the real encoder pass
+func (re *realEncoder) metricRegistry() metrics.Registry {
+	return re.registry
+}
diff --git a/vendor/github.com/Shopify/sarama/record.go b/vendor/github.com/Shopify/sarama/record.go
new file mode 100644
index 0000000..cdccfe3
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/record.go
@@ -0,0 +1,116 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"time"
+)
+
+const (
+	isTransactionalMask   = 0x10
+	controlMask           = 0x20
+	maximumRecordOverhead = 5*binary.MaxVarintLen32 + binary.MaxVarintLen64 + 1
+)
+
+//RecordHeader stores key and value for a record header
+type RecordHeader struct {
+	Key   []byte
+	Value []byte
+}
+
+func (h *RecordHeader) encode(pe packetEncoder) error {
+	if err := pe.putVarintBytes(h.Key); err != nil {
+		return err
+	}
+	return pe.putVarintBytes(h.Value)
+}
+
+func (h *RecordHeader) decode(pd packetDecoder) (err error) {
+	if h.Key, err = pd.getVarintBytes(); err != nil {
+		return err
+	}
+
+	if h.Value, err = pd.getVarintBytes(); err != nil {
+		return err
+	}
+	return nil
+}
+
+//Record is kafka record type
+type Record struct {
+	Headers []*RecordHeader
+
+	Attributes     int8
+	TimestampDelta time.Duration
+	OffsetDelta    int64
+	Key            []byte
+	Value          []byte
+	length         varintLengthField
+}
+
+func (r *Record) encode(pe packetEncoder) error {
+	pe.push(&r.length)
+	pe.putInt8(r.Attributes)
+	pe.putVarint(int64(r.TimestampDelta / time.Millisecond))
+	pe.putVarint(r.OffsetDelta)
+	if err := pe.putVarintBytes(r.Key); err != nil {
+		return err
+	}
+	if err := pe.putVarintBytes(r.Value); err != nil {
+		return err
+	}
+	pe.putVarint(int64(len(r.Headers)))
+
+	for _, h := range r.Headers {
+		if err := h.encode(pe); err != nil {
+			return err
+		}
+	}
+
+	return pe.pop()
+}
+
+func (r *Record) decode(pd packetDecoder) (err error) {
+	if err = pd.push(&r.length); err != nil {
+		return err
+	}
+
+	if r.Attributes, err = pd.getInt8(); err != nil {
+		return err
+	}
+
+	timestamp, err := pd.getVarint()
+	if err != nil {
+		return err
+	}
+	r.TimestampDelta = time.Duration(timestamp) * time.Millisecond
+
+	if r.OffsetDelta, err = pd.getVarint(); err != nil {
+		return err
+	}
+
+	if r.Key, err = pd.getVarintBytes(); err != nil {
+		return err
+	}
+
+	if r.Value, err = pd.getVarintBytes(); err != nil {
+		return err
+	}
+
+	numHeaders, err := pd.getVarint()
+	if err != nil {
+		return err
+	}
+
+	if numHeaders >= 0 {
+		r.Headers = make([]*RecordHeader, numHeaders)
+	}
+	for i := int64(0); i < numHeaders; i++ {
+		hdr := new(RecordHeader)
+		if err := hdr.decode(pd); err != nil {
+			return err
+		}
+		r.Headers[i] = hdr
+	}
+
+	return pd.pop()
+}
diff --git a/vendor/github.com/Shopify/sarama/record_batch.go b/vendor/github.com/Shopify/sarama/record_batch.go
new file mode 100644
index 0000000..c653763
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/record_batch.go
@@ -0,0 +1,225 @@
+package sarama
+
+import (
+	"fmt"
+	"time"
+)
+
+const recordBatchOverhead = 49
+
+type recordsArray []*Record
+
+func (e recordsArray) encode(pe packetEncoder) error {
+	for _, r := range e {
+		if err := r.encode(pe); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (e recordsArray) decode(pd packetDecoder) error {
+	for i := range e {
+		rec := &Record{}
+		if err := rec.decode(pd); err != nil {
+			return err
+		}
+		e[i] = rec
+	}
+	return nil
+}
+
+type RecordBatch struct {
+	FirstOffset           int64
+	PartitionLeaderEpoch  int32
+	Version               int8
+	Codec                 CompressionCodec
+	CompressionLevel      int
+	Control               bool
+	LogAppendTime         bool
+	LastOffsetDelta       int32
+	FirstTimestamp        time.Time
+	MaxTimestamp          time.Time
+	ProducerID            int64
+	ProducerEpoch         int16
+	FirstSequence         int32
+	Records               []*Record
+	PartialTrailingRecord bool
+	IsTransactional       bool
+
+	compressedRecords []byte
+	recordsLen        int // uncompressed records size
+}
+
+func (b *RecordBatch) LastOffset() int64 {
+	return b.FirstOffset + int64(b.LastOffsetDelta)
+}
+
+func (b *RecordBatch) encode(pe packetEncoder) error {
+	if b.Version != 2 {
+		return PacketEncodingError{fmt.Sprintf("unsupported compression codec (%d)", b.Codec)}
+	}
+	pe.putInt64(b.FirstOffset)
+	pe.push(&lengthField{})
+	pe.putInt32(b.PartitionLeaderEpoch)
+	pe.putInt8(b.Version)
+	pe.push(newCRC32Field(crcCastagnoli))
+	pe.putInt16(b.computeAttributes())
+	pe.putInt32(b.LastOffsetDelta)
+
+	if err := (Timestamp{&b.FirstTimestamp}).encode(pe); err != nil {
+		return err
+	}
+
+	if err := (Timestamp{&b.MaxTimestamp}).encode(pe); err != nil {
+		return err
+	}
+
+	pe.putInt64(b.ProducerID)
+	pe.putInt16(b.ProducerEpoch)
+	pe.putInt32(b.FirstSequence)
+
+	if err := pe.putArrayLength(len(b.Records)); err != nil {
+		return err
+	}
+
+	if b.compressedRecords == nil {
+		if err := b.encodeRecords(pe); err != nil {
+			return err
+		}
+	}
+	if err := pe.putRawBytes(b.compressedRecords); err != nil {
+		return err
+	}
+
+	if err := pe.pop(); err != nil {
+		return err
+	}
+	return pe.pop()
+}
+
+func (b *RecordBatch) decode(pd packetDecoder) (err error) {
+	if b.FirstOffset, err = pd.getInt64(); err != nil {
+		return err
+	}
+
+	batchLen, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+
+	if b.PartitionLeaderEpoch, err = pd.getInt32(); err != nil {
+		return err
+	}
+
+	if b.Version, err = pd.getInt8(); err != nil {
+		return err
+	}
+
+	crc32Decoder := acquireCrc32Field(crcCastagnoli)
+	defer releaseCrc32Field(crc32Decoder)
+
+	if err = pd.push(crc32Decoder); err != nil {
+		return err
+	}
+
+	attributes, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+	b.Codec = CompressionCodec(int8(attributes) & compressionCodecMask)
+	b.Control = attributes&controlMask == controlMask
+	b.LogAppendTime = attributes&timestampTypeMask == timestampTypeMask
+	b.IsTransactional = attributes&isTransactionalMask == isTransactionalMask
+
+	if b.LastOffsetDelta, err = pd.getInt32(); err != nil {
+		return err
+	}
+
+	if err = (Timestamp{&b.FirstTimestamp}).decode(pd); err != nil {
+		return err
+	}
+
+	if err = (Timestamp{&b.MaxTimestamp}).decode(pd); err != nil {
+		return err
+	}
+
+	if b.ProducerID, err = pd.getInt64(); err != nil {
+		return err
+	}
+
+	if b.ProducerEpoch, err = pd.getInt16(); err != nil {
+		return err
+	}
+
+	if b.FirstSequence, err = pd.getInt32(); err != nil {
+		return err
+	}
+
+	numRecs, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if numRecs >= 0 {
+		b.Records = make([]*Record, numRecs)
+	}
+
+	bufSize := int(batchLen) - recordBatchOverhead
+	recBuffer, err := pd.getRawBytes(bufSize)
+	if err != nil {
+		if err == ErrInsufficientData {
+			b.PartialTrailingRecord = true
+			b.Records = nil
+			return nil
+		}
+		return err
+	}
+
+	if err = pd.pop(); err != nil {
+		return err
+	}
+
+	recBuffer, err = decompress(b.Codec, recBuffer)
+	if err != nil {
+		return err
+	}
+
+	b.recordsLen = len(recBuffer)
+	err = decode(recBuffer, recordsArray(b.Records))
+	if err == ErrInsufficientData {
+		b.PartialTrailingRecord = true
+		b.Records = nil
+		return nil
+	}
+	return err
+}
+
+func (b *RecordBatch) encodeRecords(pe packetEncoder) error {
+	var raw []byte
+	var err error
+	if raw, err = encode(recordsArray(b.Records), pe.metricRegistry()); err != nil {
+		return err
+	}
+	b.recordsLen = len(raw)
+
+	b.compressedRecords, err = compress(b.Codec, b.CompressionLevel, raw)
+	return err
+}
+
+func (b *RecordBatch) computeAttributes() int16 {
+	attr := int16(b.Codec) & int16(compressionCodecMask)
+	if b.Control {
+		attr |= controlMask
+	}
+	if b.LogAppendTime {
+		attr |= timestampTypeMask
+	}
+	if b.IsTransactional {
+		attr |= isTransactionalMask
+	}
+	return attr
+}
+
+func (b *RecordBatch) addRecord(r *Record) {
+	b.Records = append(b.Records, r)
+}
diff --git a/vendor/github.com/Shopify/sarama/records.go b/vendor/github.com/Shopify/sarama/records.go
new file mode 100644
index 0000000..98160c7
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/records.go
@@ -0,0 +1,204 @@
+package sarama
+
+import "fmt"
+
+const (
+	unknownRecords = iota
+	legacyRecords
+	defaultRecords
+
+	magicOffset = 16
+	magicLength = 1
+)
+
+// Records implements a union type containing either a RecordBatch or a legacy MessageSet.
+type Records struct {
+	recordsType int
+	MsgSet      *MessageSet
+	RecordBatch *RecordBatch
+}
+
+func newLegacyRecords(msgSet *MessageSet) Records {
+	return Records{recordsType: legacyRecords, MsgSet: msgSet}
+}
+
+func newDefaultRecords(batch *RecordBatch) Records {
+	return Records{recordsType: defaultRecords, RecordBatch: batch}
+}
+
+// setTypeFromFields sets type of Records depending on which of MsgSet or RecordBatch is not nil.
+// The first return value indicates whether both fields are nil (and the type is not set).
+// If both fields are not nil, it returns an error.
+func (r *Records) setTypeFromFields() (bool, error) {
+	if r.MsgSet == nil && r.RecordBatch == nil {
+		return true, nil
+	}
+	if r.MsgSet != nil && r.RecordBatch != nil {
+		return false, fmt.Errorf("both MsgSet and RecordBatch are set, but record type is unknown")
+	}
+	r.recordsType = defaultRecords
+	if r.MsgSet != nil {
+		r.recordsType = legacyRecords
+	}
+	return false, nil
+}
+
+func (r *Records) encode(pe packetEncoder) error {
+	if r.recordsType == unknownRecords {
+		if empty, err := r.setTypeFromFields(); err != nil || empty {
+			return err
+		}
+	}
+
+	switch r.recordsType {
+	case legacyRecords:
+		if r.MsgSet == nil {
+			return nil
+		}
+		return r.MsgSet.encode(pe)
+	case defaultRecords:
+		if r.RecordBatch == nil {
+			return nil
+		}
+		return r.RecordBatch.encode(pe)
+	}
+
+	return fmt.Errorf("unknown records type: %v", r.recordsType)
+}
+
+func (r *Records) setTypeFromMagic(pd packetDecoder) error {
+	magic, err := magicValue(pd)
+	if err != nil {
+		return err
+	}
+
+	r.recordsType = defaultRecords
+	if magic < 2 {
+		r.recordsType = legacyRecords
+	}
+
+	return nil
+}
+
+func (r *Records) decode(pd packetDecoder) error {
+	if r.recordsType == unknownRecords {
+		if err := r.setTypeFromMagic(pd); err != nil {
+			return err
+		}
+	}
+
+	switch r.recordsType {
+	case legacyRecords:
+		r.MsgSet = &MessageSet{}
+		return r.MsgSet.decode(pd)
+	case defaultRecords:
+		r.RecordBatch = &RecordBatch{}
+		return r.RecordBatch.decode(pd)
+	}
+	return fmt.Errorf("unknown records type: %v", r.recordsType)
+}
+
+func (r *Records) numRecords() (int, error) {
+	if r.recordsType == unknownRecords {
+		if empty, err := r.setTypeFromFields(); err != nil || empty {
+			return 0, err
+		}
+	}
+
+	switch r.recordsType {
+	case legacyRecords:
+		if r.MsgSet == nil {
+			return 0, nil
+		}
+		return len(r.MsgSet.Messages), nil
+	case defaultRecords:
+		if r.RecordBatch == nil {
+			return 0, nil
+		}
+		return len(r.RecordBatch.Records), nil
+	}
+	return 0, fmt.Errorf("unknown records type: %v", r.recordsType)
+}
+
+func (r *Records) isPartial() (bool, error) {
+	if r.recordsType == unknownRecords {
+		if empty, err := r.setTypeFromFields(); err != nil || empty {
+			return false, err
+		}
+	}
+
+	switch r.recordsType {
+	case unknownRecords:
+		return false, nil
+	case legacyRecords:
+		if r.MsgSet == nil {
+			return false, nil
+		}
+		return r.MsgSet.PartialTrailingMessage, nil
+	case defaultRecords:
+		if r.RecordBatch == nil {
+			return false, nil
+		}
+		return r.RecordBatch.PartialTrailingRecord, nil
+	}
+	return false, fmt.Errorf("unknown records type: %v", r.recordsType)
+}
+
+func (r *Records) isControl() (bool, error) {
+	if r.recordsType == unknownRecords {
+		if empty, err := r.setTypeFromFields(); err != nil || empty {
+			return false, err
+		}
+	}
+
+	switch r.recordsType {
+	case legacyRecords:
+		return false, nil
+	case defaultRecords:
+		if r.RecordBatch == nil {
+			return false, nil
+		}
+		return r.RecordBatch.Control, nil
+	}
+	return false, fmt.Errorf("unknown records type: %v", r.recordsType)
+}
+
+func (r *Records) isOverflow() (bool, error) {
+	if r.recordsType == unknownRecords {
+		if empty, err := r.setTypeFromFields(); err != nil || empty {
+			return false, err
+		}
+	}
+
+	switch r.recordsType {
+	case unknownRecords:
+		return false, nil
+	case legacyRecords:
+		if r.MsgSet == nil {
+			return false, nil
+		}
+		return r.MsgSet.OverflowMessage, nil
+	case defaultRecords:
+		return false, nil
+	}
+	return false, fmt.Errorf("unknown records type: %v", r.recordsType)
+}
+
+func magicValue(pd packetDecoder) (int8, error) {
+	return pd.peekInt8(magicOffset)
+}
+
+func (r *Records) getControlRecord() (ControlRecord, error) {
+	if r.RecordBatch == nil || len(r.RecordBatch.Records) <= 0 {
+		return ControlRecord{}, fmt.Errorf("cannot get control record, record batch is empty")
+	}
+
+	firstRecord := r.RecordBatch.Records[0]
+	controlRecord := ControlRecord{}
+	err := controlRecord.decode(&realDecoder{raw: firstRecord.Key}, &realDecoder{raw: firstRecord.Value})
+	if err != nil {
+		return ControlRecord{}, err
+	}
+
+	return controlRecord, nil
+}
diff --git a/vendor/github.com/Shopify/sarama/request.go b/vendor/github.com/Shopify/sarama/request.go
new file mode 100644
index 0000000..97437d6
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/request.go
@@ -0,0 +1,171 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+type protocolBody interface {
+	encoder
+	versionedDecoder
+	key() int16
+	version() int16
+	requiredVersion() KafkaVersion
+}
+
+type request struct {
+	correlationID int32
+	clientID      string
+	body          protocolBody
+}
+
+func (r *request) encode(pe packetEncoder) error {
+	pe.push(&lengthField{})
+	pe.putInt16(r.body.key())
+	pe.putInt16(r.body.version())
+	pe.putInt32(r.correlationID)
+
+	err := pe.putString(r.clientID)
+	if err != nil {
+		return err
+	}
+
+	err = r.body.encode(pe)
+	if err != nil {
+		return err
+	}
+
+	return pe.pop()
+}
+
+func (r *request) decode(pd packetDecoder) (err error) {
+	key, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+
+	version, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+
+	r.correlationID, err = pd.getInt32()
+	if err != nil {
+		return err
+	}
+
+	r.clientID, err = pd.getString()
+	if err != nil {
+		return err
+	}
+
+	r.body = allocateBody(key, version)
+	if r.body == nil {
+		return PacketDecodingError{fmt.Sprintf("unknown request key (%d)", key)}
+	}
+
+	return r.body.decode(pd, version)
+}
+
+func decodeRequest(r io.Reader) (*request, int, error) {
+	var (
+		bytesRead   int
+		lengthBytes = make([]byte, 4)
+	)
+
+	if _, err := io.ReadFull(r, lengthBytes); err != nil {
+		return nil, bytesRead, err
+	}
+
+	bytesRead += len(lengthBytes)
+	length := int32(binary.BigEndian.Uint32(lengthBytes))
+
+	if length <= 4 || length > MaxRequestSize {
+		return nil, bytesRead, PacketDecodingError{fmt.Sprintf("message of length %d too large or too small", length)}
+	}
+
+	encodedReq := make([]byte, length)
+	if _, err := io.ReadFull(r, encodedReq); err != nil {
+		return nil, bytesRead, err
+	}
+
+	bytesRead += len(encodedReq)
+
+	req := &request{}
+	if err := decode(encodedReq, req); err != nil {
+		return nil, bytesRead, err
+	}
+
+	return req, bytesRead, nil
+}
+
+func allocateBody(key, version int16) protocolBody {
+	switch key {
+	case 0:
+		return &ProduceRequest{}
+	case 1:
+		return &FetchRequest{}
+	case 2:
+		return &OffsetRequest{Version: version}
+	case 3:
+		return &MetadataRequest{}
+	case 8:
+		return &OffsetCommitRequest{Version: version}
+	case 9:
+		return &OffsetFetchRequest{}
+	case 10:
+		return &FindCoordinatorRequest{}
+	case 11:
+		return &JoinGroupRequest{}
+	case 12:
+		return &HeartbeatRequest{}
+	case 13:
+		return &LeaveGroupRequest{}
+	case 14:
+		return &SyncGroupRequest{}
+	case 15:
+		return &DescribeGroupsRequest{}
+	case 16:
+		return &ListGroupsRequest{}
+	case 17:
+		return &SaslHandshakeRequest{}
+	case 18:
+		return &ApiVersionsRequest{}
+	case 19:
+		return &CreateTopicsRequest{}
+	case 20:
+		return &DeleteTopicsRequest{}
+	case 21:
+		return &DeleteRecordsRequest{}
+	case 22:
+		return &InitProducerIDRequest{}
+	case 24:
+		return &AddPartitionsToTxnRequest{}
+	case 25:
+		return &AddOffsetsToTxnRequest{}
+	case 26:
+		return &EndTxnRequest{}
+	case 28:
+		return &TxnOffsetCommitRequest{}
+	case 29:
+		return &DescribeAclsRequest{}
+	case 30:
+		return &CreateAclsRequest{}
+	case 31:
+		return &DeleteAclsRequest{}
+	case 32:
+		return &DescribeConfigsRequest{}
+	case 33:
+		return &AlterConfigsRequest{}
+	case 35:
+		return &DescribeLogDirsRequest{}
+	case 36:
+		return &SaslAuthenticateRequest{}
+	case 37:
+		return &CreatePartitionsRequest{}
+	case 42:
+		return &DeleteGroupsRequest{}
+	}
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/response_header.go b/vendor/github.com/Shopify/sarama/response_header.go
new file mode 100644
index 0000000..7a75918
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/response_header.go
@@ -0,0 +1,24 @@
+package sarama
+
+import "fmt"
+
+const responseLengthSize = 4
+const correlationIDSize = 4
+
+type responseHeader struct {
+	length        int32
+	correlationID int32
+}
+
+func (r *responseHeader) decode(pd packetDecoder) (err error) {
+	r.length, err = pd.getInt32()
+	if err != nil {
+		return err
+	}
+	if r.length <= 4 || r.length > MaxResponseSize {
+		return PacketDecodingError{fmt.Sprintf("message of length %d too large or too small", r.length)}
+	}
+
+	r.correlationID, err = pd.getInt32()
+	return err
+}
diff --git a/vendor/github.com/Shopify/sarama/sarama.go b/vendor/github.com/Shopify/sarama/sarama.go
new file mode 100644
index 0000000..1e0277a
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/sarama.go
@@ -0,0 +1,106 @@
+/*
+Package sarama is a pure Go client library for dealing with Apache Kafka (versions 0.8 and later). It includes a high-level
+API for easily producing and consuming messages, and a low-level API for controlling bytes on the wire when the high-level
+API is insufficient. Usage examples for the high-level APIs are provided inline with their full documentation.
+
+To produce messages, use either the AsyncProducer or the SyncProducer. The AsyncProducer accepts messages on a channel
+and produces them asynchronously in the background as efficiently as possible; it is preferred in most cases.
+The SyncProducer provides a method which will block until Kafka acknowledges the message as produced. This can be
+useful but comes with two caveats: it will generally be less efficient, and the actual durability guarantees
+depend on the configured value of `Producer.RequiredAcks`. There are configurations where a message acknowledged by the
+SyncProducer can still sometimes be lost.
+
+To consume messages, use Consumer or Consumer-Group API.
+
+For lower-level needs, the Broker and Request/Response objects permit precise control over each connection
+and message sent on the wire; the Client provides higher-level metadata management that is shared between
+the producers and the consumer. The Request/Response objects and properties are mostly undocumented, as they line up
+exactly with the protocol fields documented by Kafka at
+https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol
+
+Metrics are exposed through https://github.com/rcrowley/go-metrics library in a local registry.
+
+Broker related metrics:
+
+	+----------------------------------------------+------------+---------------------------------------------------------------+
+	| Name                                         | Type       | Description                                                   |
+	+----------------------------------------------+------------+---------------------------------------------------------------+
+	| incoming-byte-rate                           | meter      | Bytes/second read off all brokers                             |
+	| incoming-byte-rate-for-broker-<broker-id>    | meter      | Bytes/second read off a given broker                          |
+	| outgoing-byte-rate                           | meter      | Bytes/second written off all brokers                          |
+	| outgoing-byte-rate-for-broker-<broker-id>    | meter      | Bytes/second written off a given broker                       |
+	| request-rate                                 | meter      | Requests/second sent to all brokers                           |
+	| request-rate-for-broker-<broker-id>          | meter      | Requests/second sent to a given broker                        |
+	| request-size                                 | histogram  | Distribution of the request size in bytes for all brokers     |
+	| request-size-for-broker-<broker-id>          | histogram  | Distribution of the request size in bytes for a given broker  |
+	| request-latency-in-ms                        | histogram  | Distribution of the request latency in ms for all brokers     |
+	| request-latency-in-ms-for-broker-<broker-id> | histogram  | Distribution of the request latency in ms for a given broker  |
+	| response-rate                                | meter      | Responses/second received from all brokers                    |
+	| response-rate-for-broker-<broker-id>         | meter      | Responses/second received from a given broker                 |
+	| response-size                                | histogram  | Distribution of the response size in bytes for all brokers    |
+	| response-size-for-broker-<broker-id>         | histogram  | Distribution of the response size in bytes for a given broker |
+	+----------------------------------------------+------------+---------------------------------------------------------------+
+
+Note that we do not gather specific metrics for seed brokers but they are part of the "all brokers" metrics.
+
+Producer related metrics:
+
+	+-------------------------------------------+------------+--------------------------------------------------------------------------------------+
+	| Name                                      | Type       | Description                                                                          |
+	+-------------------------------------------+------------+--------------------------------------------------------------------------------------+
+	| batch-size                                | histogram  | Distribution of the number of bytes sent per partition per request for all topics    |
+	| batch-size-for-topic-<topic>              | histogram  | Distribution of the number of bytes sent per partition per request for a given topic |
+	| record-send-rate                          | meter      | Records/second sent to all topics                                                    |
+	| record-send-rate-for-topic-<topic>        | meter      | Records/second sent to a given topic                                                 |
+	| records-per-request                       | histogram  | Distribution of the number of records sent per request for all topics                |
+	| records-per-request-for-topic-<topic>     | histogram  | Distribution of the number of records sent per request for a given topic             |
+	| compression-ratio                         | histogram  | Distribution of the compression ratio times 100 of record batches for all topics     |
+	| compression-ratio-for-topic-<topic>       | histogram  | Distribution of the compression ratio times 100 of record batches for a given topic  |
+	+-------------------------------------------+------------+--------------------------------------------------------------------------------------+
+
+Consumer related metrics:
+
+	+-------------------------------------------+------------+--------------------------------------------------------------------------------------+
+	| Name                                      | Type       | Description                                                                          |
+	+-------------------------------------------+------------+--------------------------------------------------------------------------------------+
+	| consumer-batch-size                       | histogram  | Distribution of the number of messages in a batch                                    |
+	+-------------------------------------------+------------+--------------------------------------------------------------------------------------+
+
+*/
+package sarama
+
+import (
+	"io/ioutil"
+	"log"
+)
+
+var (
+	// Logger is the instance of a StdLogger interface that Sarama writes connection
+	// management events to. By default it is set to discard all log messages via ioutil.Discard,
+	// but you can set it to redirect wherever you want.
+	Logger StdLogger = log.New(ioutil.Discard, "[Sarama] ", log.LstdFlags)
+
+	// PanicHandler is called for recovering from panics spawned internally to the library (and thus
+	// not recoverable by the caller's goroutine). Defaults to nil, which means panics are not recovered.
+	PanicHandler func(interface{})
+
+	// MaxRequestSize is the maximum size (in bytes) of any request that Sarama will attempt to send. Trying
+	// to send a request larger than this will result in an PacketEncodingError. The default of 100 MiB is aligned
+	// with Kafka's default `socket.request.max.bytes`, which is the largest request the broker will attempt
+	// to process.
+	MaxRequestSize int32 = 100 * 1024 * 1024
+
+	// MaxResponseSize is the maximum size (in bytes) of any response that Sarama will attempt to parse. If
+	// a broker returns a response message larger than this value, Sarama will return a PacketDecodingError to
+	// protect the client from running out of memory. Please note that brokers do not have any natural limit on
+	// the size of responses they send. In particular, they can send arbitrarily large fetch responses to consumers
+	// (see https://issues.apache.org/jira/browse/KAFKA-2063).
+	MaxResponseSize int32 = 100 * 1024 * 1024
+)
+
+// StdLogger is used to log error messages.
+type StdLogger interface {
+	Print(v ...interface{})
+	Printf(format string, v ...interface{})
+	Println(v ...interface{})
+}
diff --git a/vendor/github.com/Shopify/sarama/sasl_authenticate_request.go b/vendor/github.com/Shopify/sarama/sasl_authenticate_request.go
new file mode 100644
index 0000000..54c8b09
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/sasl_authenticate_request.go
@@ -0,0 +1,29 @@
+package sarama
+
+type SaslAuthenticateRequest struct {
+	SaslAuthBytes []byte
+}
+
+// APIKeySASLAuth is the API key for the SaslAuthenticate Kafka API
+const APIKeySASLAuth = 36
+
+func (r *SaslAuthenticateRequest) encode(pe packetEncoder) error {
+	return pe.putBytes(r.SaslAuthBytes)
+}
+
+func (r *SaslAuthenticateRequest) decode(pd packetDecoder, version int16) (err error) {
+	r.SaslAuthBytes, err = pd.getBytes()
+	return err
+}
+
+func (r *SaslAuthenticateRequest) key() int16 {
+	return APIKeySASLAuth
+}
+
+func (r *SaslAuthenticateRequest) version() int16 {
+	return 0
+}
+
+func (r *SaslAuthenticateRequest) requiredVersion() KafkaVersion {
+	return V1_0_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/sasl_authenticate_response.go b/vendor/github.com/Shopify/sarama/sasl_authenticate_response.go
new file mode 100644
index 0000000..0038c3f
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/sasl_authenticate_response.go
@@ -0,0 +1,44 @@
+package sarama
+
+type SaslAuthenticateResponse struct {
+	Err           KError
+	ErrorMessage  *string
+	SaslAuthBytes []byte
+}
+
+func (r *SaslAuthenticateResponse) encode(pe packetEncoder) error {
+	pe.putInt16(int16(r.Err))
+	if err := pe.putNullableString(r.ErrorMessage); err != nil {
+		return err
+	}
+	return pe.putBytes(r.SaslAuthBytes)
+}
+
+func (r *SaslAuthenticateResponse) decode(pd packetDecoder, version int16) error {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+
+	r.Err = KError(kerr)
+
+	if r.ErrorMessage, err = pd.getNullableString(); err != nil {
+		return err
+	}
+
+	r.SaslAuthBytes, err = pd.getBytes()
+
+	return err
+}
+
+func (r *SaslAuthenticateResponse) key() int16 {
+	return APIKeySASLAuth
+}
+
+func (r *SaslAuthenticateResponse) version() int16 {
+	return 0
+}
+
+func (r *SaslAuthenticateResponse) requiredVersion() KafkaVersion {
+	return V1_0_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/sasl_handshake_request.go b/vendor/github.com/Shopify/sarama/sasl_handshake_request.go
new file mode 100644
index 0000000..fe5ba05
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/sasl_handshake_request.go
@@ -0,0 +1,34 @@
+package sarama
+
+type SaslHandshakeRequest struct {
+	Mechanism string
+	Version   int16
+}
+
+func (r *SaslHandshakeRequest) encode(pe packetEncoder) error {
+	if err := pe.putString(r.Mechanism); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *SaslHandshakeRequest) decode(pd packetDecoder, version int16) (err error) {
+	if r.Mechanism, err = pd.getString(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *SaslHandshakeRequest) key() int16 {
+	return 17
+}
+
+func (r *SaslHandshakeRequest) version() int16 {
+	return r.Version
+}
+
+func (r *SaslHandshakeRequest) requiredVersion() KafkaVersion {
+	return V0_10_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/sasl_handshake_response.go b/vendor/github.com/Shopify/sarama/sasl_handshake_response.go
new file mode 100644
index 0000000..ef290d4
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/sasl_handshake_response.go
@@ -0,0 +1,38 @@
+package sarama
+
+type SaslHandshakeResponse struct {
+	Err               KError
+	EnabledMechanisms []string
+}
+
+func (r *SaslHandshakeResponse) encode(pe packetEncoder) error {
+	pe.putInt16(int16(r.Err))
+	return pe.putStringArray(r.EnabledMechanisms)
+}
+
+func (r *SaslHandshakeResponse) decode(pd packetDecoder, version int16) error {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+
+	r.Err = KError(kerr)
+
+	if r.EnabledMechanisms, err = pd.getStringArray(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (r *SaslHandshakeResponse) key() int16 {
+	return 17
+}
+
+func (r *SaslHandshakeResponse) version() int16 {
+	return 0
+}
+
+func (r *SaslHandshakeResponse) requiredVersion() KafkaVersion {
+	return V0_10_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/sticky_assignor_user_data.go b/vendor/github.com/Shopify/sarama/sticky_assignor_user_data.go
new file mode 100644
index 0000000..bb0c82c
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/sticky_assignor_user_data.go
@@ -0,0 +1,124 @@
+package sarama
+
+type topicPartitionAssignment struct {
+	Topic     string
+	Partition int32
+}
+
+type StickyAssignorUserData interface {
+	partitions() []topicPartitionAssignment
+	hasGeneration() bool
+	generation() int
+}
+
+//StickyAssignorUserDataV0 holds topic partition information for an assignment
+type StickyAssignorUserDataV0 struct {
+	Topics map[string][]int32
+
+	topicPartitions []topicPartitionAssignment
+}
+
+func (m *StickyAssignorUserDataV0) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(m.Topics)); err != nil {
+		return err
+	}
+
+	for topic, partitions := range m.Topics {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putInt32Array(partitions); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m *StickyAssignorUserDataV0) decode(pd packetDecoder) (err error) {
+	var topicLen int
+	if topicLen, err = pd.getArrayLength(); err != nil {
+		return
+	}
+
+	m.Topics = make(map[string][]int32, topicLen)
+	for i := 0; i < topicLen; i++ {
+		var topic string
+		if topic, err = pd.getString(); err != nil {
+			return
+		}
+		if m.Topics[topic], err = pd.getInt32Array(); err != nil {
+			return
+		}
+	}
+	m.topicPartitions = populateTopicPartitions(m.Topics)
+	return nil
+}
+
+func (m *StickyAssignorUserDataV0) partitions() []topicPartitionAssignment { return m.topicPartitions }
+func (m *StickyAssignorUserDataV0) hasGeneration() bool                    { return false }
+func (m *StickyAssignorUserDataV0) generation() int                        { return defaultGeneration }
+
+//StickyAssignorUserDataV1 holds topic partition information for an assignment
+type StickyAssignorUserDataV1 struct {
+	Topics     map[string][]int32
+	Generation int32
+
+	topicPartitions []topicPartitionAssignment
+}
+
+func (m *StickyAssignorUserDataV1) encode(pe packetEncoder) error {
+	if err := pe.putArrayLength(len(m.Topics)); err != nil {
+		return err
+	}
+
+	for topic, partitions := range m.Topics {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putInt32Array(partitions); err != nil {
+			return err
+		}
+	}
+
+	pe.putInt32(m.Generation)
+	return nil
+}
+
+func (m *StickyAssignorUserDataV1) decode(pd packetDecoder) (err error) {
+	var topicLen int
+	if topicLen, err = pd.getArrayLength(); err != nil {
+		return
+	}
+
+	m.Topics = make(map[string][]int32, topicLen)
+	for i := 0; i < topicLen; i++ {
+		var topic string
+		if topic, err = pd.getString(); err != nil {
+			return
+		}
+		if m.Topics[topic], err = pd.getInt32Array(); err != nil {
+			return
+		}
+	}
+
+	m.Generation, err = pd.getInt32()
+	if err != nil {
+		return err
+	}
+	m.topicPartitions = populateTopicPartitions(m.Topics)
+	return nil
+}
+
+func (m *StickyAssignorUserDataV1) partitions() []topicPartitionAssignment { return m.topicPartitions }
+func (m *StickyAssignorUserDataV1) hasGeneration() bool                    { return true }
+func (m *StickyAssignorUserDataV1) generation() int                        { return int(m.Generation) }
+
+func populateTopicPartitions(topics map[string][]int32) []topicPartitionAssignment {
+	topicPartitions := make([]topicPartitionAssignment, 0)
+	for topic, partitions := range topics {
+		for _, partition := range partitions {
+			topicPartitions = append(topicPartitions, topicPartitionAssignment{Topic: topic, Partition: partition})
+		}
+	}
+	return topicPartitions
+}
diff --git a/vendor/github.com/Shopify/sarama/sync_group_request.go b/vendor/github.com/Shopify/sarama/sync_group_request.go
new file mode 100644
index 0000000..fe20708
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/sync_group_request.go
@@ -0,0 +1,100 @@
+package sarama
+
+type SyncGroupRequest struct {
+	GroupId          string
+	GenerationId     int32
+	MemberId         string
+	GroupAssignments map[string][]byte
+}
+
+func (r *SyncGroupRequest) encode(pe packetEncoder) error {
+	if err := pe.putString(r.GroupId); err != nil {
+		return err
+	}
+
+	pe.putInt32(r.GenerationId)
+
+	if err := pe.putString(r.MemberId); err != nil {
+		return err
+	}
+
+	if err := pe.putArrayLength(len(r.GroupAssignments)); err != nil {
+		return err
+	}
+	for memberId, memberAssignment := range r.GroupAssignments {
+		if err := pe.putString(memberId); err != nil {
+			return err
+		}
+		if err := pe.putBytes(memberAssignment); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *SyncGroupRequest) decode(pd packetDecoder, version int16) (err error) {
+	if r.GroupId, err = pd.getString(); err != nil {
+		return
+	}
+	if r.GenerationId, err = pd.getInt32(); err != nil {
+		return
+	}
+	if r.MemberId, err = pd.getString(); err != nil {
+		return
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if n == 0 {
+		return nil
+	}
+
+	r.GroupAssignments = make(map[string][]byte)
+	for i := 0; i < n; i++ {
+		memberId, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		memberAssignment, err := pd.getBytes()
+		if err != nil {
+			return err
+		}
+
+		r.GroupAssignments[memberId] = memberAssignment
+	}
+
+	return nil
+}
+
+func (r *SyncGroupRequest) key() int16 {
+	return 14
+}
+
+func (r *SyncGroupRequest) version() int16 {
+	return 0
+}
+
+func (r *SyncGroupRequest) requiredVersion() KafkaVersion {
+	return V0_9_0_0
+}
+
+func (r *SyncGroupRequest) AddGroupAssignment(memberId string, memberAssignment []byte) {
+	if r.GroupAssignments == nil {
+		r.GroupAssignments = make(map[string][]byte)
+	}
+
+	r.GroupAssignments[memberId] = memberAssignment
+}
+
+func (r *SyncGroupRequest) AddGroupAssignmentMember(memberId string, memberAssignment *ConsumerGroupMemberAssignment) error {
+	bin, err := encode(memberAssignment, nil)
+	if err != nil {
+		return err
+	}
+
+	r.AddGroupAssignment(memberId, bin)
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/sync_group_response.go b/vendor/github.com/Shopify/sarama/sync_group_response.go
new file mode 100644
index 0000000..194b382
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/sync_group_response.go
@@ -0,0 +1,41 @@
+package sarama
+
+type SyncGroupResponse struct {
+	Err              KError
+	MemberAssignment []byte
+}
+
+func (r *SyncGroupResponse) GetMemberAssignment() (*ConsumerGroupMemberAssignment, error) {
+	assignment := new(ConsumerGroupMemberAssignment)
+	err := decode(r.MemberAssignment, assignment)
+	return assignment, err
+}
+
+func (r *SyncGroupResponse) encode(pe packetEncoder) error {
+	pe.putInt16(int16(r.Err))
+	return pe.putBytes(r.MemberAssignment)
+}
+
+func (r *SyncGroupResponse) decode(pd packetDecoder, version int16) (err error) {
+	kerr, err := pd.getInt16()
+	if err != nil {
+		return err
+	}
+
+	r.Err = KError(kerr)
+
+	r.MemberAssignment, err = pd.getBytes()
+	return
+}
+
+func (r *SyncGroupResponse) key() int16 {
+	return 14
+}
+
+func (r *SyncGroupResponse) version() int16 {
+	return 0
+}
+
+func (r *SyncGroupResponse) requiredVersion() KafkaVersion {
+	return V0_9_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/sync_producer.go b/vendor/github.com/Shopify/sarama/sync_producer.go
new file mode 100644
index 0000000..021c5a0
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/sync_producer.go
@@ -0,0 +1,149 @@
+package sarama
+
+import "sync"
+
+// SyncProducer publishes Kafka messages, blocking until they have been acknowledged. It routes messages to the correct
+// broker, refreshing metadata as appropriate, and parses responses for errors. You must call Close() on a producer
+// to avoid leaks, it may not be garbage-collected automatically when it passes out of scope.
+//
+// The SyncProducer comes with two caveats: it will generally be less efficient than the AsyncProducer, and the actual
+// durability guarantee provided when a message is acknowledged depend on the configured value of `Producer.RequiredAcks`.
+// There are configurations where a message acknowledged by the SyncProducer can still sometimes be lost.
+//
+// For implementation reasons, the SyncProducer requires `Producer.Return.Errors` and `Producer.Return.Successes` to
+// be set to true in its configuration.
+type SyncProducer interface {
+
+	// SendMessage produces a given message, and returns only when it either has
+	// succeeded or failed to produce. It will return the partition and the offset
+	// of the produced message, or an error if the message failed to produce.
+	SendMessage(msg *ProducerMessage) (partition int32, offset int64, err error)
+
+	// SendMessages produces a given set of messages, and returns only when all
+	// messages in the set have either succeeded or failed. Note that messages
+	// can succeed and fail individually; if some succeed and some fail,
+	// SendMessages will return an error.
+	SendMessages(msgs []*ProducerMessage) error
+
+	// Close shuts down the producer and waits for any buffered messages to be
+	// flushed. You must call this function before a producer object passes out of
+	// scope, as it may otherwise leak memory. You must call this before calling
+	// Close on the underlying client.
+	Close() error
+}
+
+type syncProducer struct {
+	producer *asyncProducer
+	wg       sync.WaitGroup
+}
+
+// NewSyncProducer creates a new SyncProducer using the given broker addresses and configuration.
+func NewSyncProducer(addrs []string, config *Config) (SyncProducer, error) {
+	if config == nil {
+		config = NewConfig()
+		config.Producer.Return.Successes = true
+	}
+
+	if err := verifyProducerConfig(config); err != nil {
+		return nil, err
+	}
+
+	p, err := NewAsyncProducer(addrs, config)
+	if err != nil {
+		return nil, err
+	}
+	return newSyncProducerFromAsyncProducer(p.(*asyncProducer)), nil
+}
+
+// NewSyncProducerFromClient creates a new SyncProducer using the given client. It is still
+// necessary to call Close() on the underlying client when shutting down this producer.
+func NewSyncProducerFromClient(client Client) (SyncProducer, error) {
+	if err := verifyProducerConfig(client.Config()); err != nil {
+		return nil, err
+	}
+
+	p, err := NewAsyncProducerFromClient(client)
+	if err != nil {
+		return nil, err
+	}
+	return newSyncProducerFromAsyncProducer(p.(*asyncProducer)), nil
+}
+
+func newSyncProducerFromAsyncProducer(p *asyncProducer) *syncProducer {
+	sp := &syncProducer{producer: p}
+
+	sp.wg.Add(2)
+	go withRecover(sp.handleSuccesses)
+	go withRecover(sp.handleErrors)
+
+	return sp
+}
+
+func verifyProducerConfig(config *Config) error {
+	if !config.Producer.Return.Errors {
+		return ConfigurationError("Producer.Return.Errors must be true to be used in a SyncProducer")
+	}
+	if !config.Producer.Return.Successes {
+		return ConfigurationError("Producer.Return.Successes must be true to be used in a SyncProducer")
+	}
+	return nil
+}
+
+func (sp *syncProducer) SendMessage(msg *ProducerMessage) (partition int32, offset int64, err error) {
+	expectation := make(chan *ProducerError, 1)
+	msg.expectation = expectation
+	sp.producer.Input() <- msg
+
+	if err := <-expectation; err != nil {
+		return -1, -1, err.Err
+	}
+
+	return msg.Partition, msg.Offset, nil
+}
+
+func (sp *syncProducer) SendMessages(msgs []*ProducerMessage) error {
+	expectations := make(chan chan *ProducerError, len(msgs))
+	go func() {
+		for _, msg := range msgs {
+			expectation := make(chan *ProducerError, 1)
+			msg.expectation = expectation
+			sp.producer.Input() <- msg
+			expectations <- expectation
+		}
+		close(expectations)
+	}()
+
+	var errors ProducerErrors
+	for expectation := range expectations {
+		if err := <-expectation; err != nil {
+			errors = append(errors, err)
+		}
+	}
+
+	if len(errors) > 0 {
+		return errors
+	}
+	return nil
+}
+
+func (sp *syncProducer) handleSuccesses() {
+	defer sp.wg.Done()
+	for msg := range sp.producer.Successes() {
+		expectation := msg.expectation
+		expectation <- nil
+	}
+}
+
+func (sp *syncProducer) handleErrors() {
+	defer sp.wg.Done()
+	for err := range sp.producer.Errors() {
+		expectation := err.Msg.expectation
+		expectation <- err
+	}
+}
+
+func (sp *syncProducer) Close() error {
+	sp.producer.AsyncClose()
+	sp.wg.Wait()
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/timestamp.go b/vendor/github.com/Shopify/sarama/timestamp.go
new file mode 100644
index 0000000..372278d
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/timestamp.go
@@ -0,0 +1,40 @@
+package sarama
+
+import (
+	"fmt"
+	"time"
+)
+
+type Timestamp struct {
+	*time.Time
+}
+
+func (t Timestamp) encode(pe packetEncoder) error {
+	timestamp := int64(-1)
+
+	if !t.Before(time.Unix(0, 0)) {
+		timestamp = t.UnixNano() / int64(time.Millisecond)
+	} else if !t.IsZero() {
+		return PacketEncodingError{fmt.Sprintf("invalid timestamp (%v)", t)}
+	}
+
+	pe.putInt64(timestamp)
+	return nil
+}
+
+func (t Timestamp) decode(pd packetDecoder) error {
+	millis, err := pd.getInt64()
+	if err != nil {
+		return err
+	}
+
+	// negative timestamps are invalid, in these cases we should return
+	// a zero time
+	timestamp := time.Time{}
+	if millis >= 0 {
+		timestamp = time.Unix(millis/1000, (millis%1000)*int64(time.Millisecond))
+	}
+
+	*t.Time = timestamp
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/txn_offset_commit_request.go b/vendor/github.com/Shopify/sarama/txn_offset_commit_request.go
new file mode 100644
index 0000000..71e95b8
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/txn_offset_commit_request.go
@@ -0,0 +1,126 @@
+package sarama
+
+type TxnOffsetCommitRequest struct {
+	TransactionalID string
+	GroupID         string
+	ProducerID      int64
+	ProducerEpoch   int16
+	Topics          map[string][]*PartitionOffsetMetadata
+}
+
+func (t *TxnOffsetCommitRequest) encode(pe packetEncoder) error {
+	if err := pe.putString(t.TransactionalID); err != nil {
+		return err
+	}
+	if err := pe.putString(t.GroupID); err != nil {
+		return err
+	}
+	pe.putInt64(t.ProducerID)
+	pe.putInt16(t.ProducerEpoch)
+
+	if err := pe.putArrayLength(len(t.Topics)); err != nil {
+		return err
+	}
+	for topic, partitions := range t.Topics {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putArrayLength(len(partitions)); err != nil {
+			return err
+		}
+		for _, partition := range partitions {
+			if err := partition.encode(pe); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (t *TxnOffsetCommitRequest) decode(pd packetDecoder, version int16) (err error) {
+	if t.TransactionalID, err = pd.getString(); err != nil {
+		return err
+	}
+	if t.GroupID, err = pd.getString(); err != nil {
+		return err
+	}
+	if t.ProducerID, err = pd.getInt64(); err != nil {
+		return err
+	}
+	if t.ProducerEpoch, err = pd.getInt16(); err != nil {
+		return err
+	}
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	t.Topics = make(map[string][]*PartitionOffsetMetadata)
+	for i := 0; i < n; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		m, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+
+		t.Topics[topic] = make([]*PartitionOffsetMetadata, m)
+
+		for j := 0; j < m; j++ {
+			partitionOffsetMetadata := new(PartitionOffsetMetadata)
+			if err := partitionOffsetMetadata.decode(pd, version); err != nil {
+				return err
+			}
+			t.Topics[topic][j] = partitionOffsetMetadata
+		}
+	}
+
+	return nil
+}
+
+func (a *TxnOffsetCommitRequest) key() int16 {
+	return 28
+}
+
+func (a *TxnOffsetCommitRequest) version() int16 {
+	return 0
+}
+
+func (a *TxnOffsetCommitRequest) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
+
+type PartitionOffsetMetadata struct {
+	Partition int32
+	Offset    int64
+	Metadata  *string
+}
+
+func (p *PartitionOffsetMetadata) encode(pe packetEncoder) error {
+	pe.putInt32(p.Partition)
+	pe.putInt64(p.Offset)
+	if err := pe.putNullableString(p.Metadata); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (p *PartitionOffsetMetadata) decode(pd packetDecoder, version int16) (err error) {
+	if p.Partition, err = pd.getInt32(); err != nil {
+		return err
+	}
+	if p.Offset, err = pd.getInt64(); err != nil {
+		return err
+	}
+	if p.Metadata, err = pd.getNullableString(); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/vendor/github.com/Shopify/sarama/txn_offset_commit_response.go b/vendor/github.com/Shopify/sarama/txn_offset_commit_response.go
new file mode 100644
index 0000000..6c980f4
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/txn_offset_commit_response.go
@@ -0,0 +1,83 @@
+package sarama
+
+import (
+	"time"
+)
+
+type TxnOffsetCommitResponse struct {
+	ThrottleTime time.Duration
+	Topics       map[string][]*PartitionError
+}
+
+func (t *TxnOffsetCommitResponse) encode(pe packetEncoder) error {
+	pe.putInt32(int32(t.ThrottleTime / time.Millisecond))
+	if err := pe.putArrayLength(len(t.Topics)); err != nil {
+		return err
+	}
+
+	for topic, e := range t.Topics {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putArrayLength(len(e)); err != nil {
+			return err
+		}
+		for _, partitionError := range e {
+			if err := partitionError.encode(pe); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (t *TxnOffsetCommitResponse) decode(pd packetDecoder, version int16) (err error) {
+	throttleTime, err := pd.getInt32()
+	if err != nil {
+		return err
+	}
+	t.ThrottleTime = time.Duration(throttleTime) * time.Millisecond
+
+	n, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+
+	t.Topics = make(map[string][]*PartitionError)
+
+	for i := 0; i < n; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+
+		m, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+
+		t.Topics[topic] = make([]*PartitionError, m)
+
+		for j := 0; j < m; j++ {
+			t.Topics[topic][j] = new(PartitionError)
+			if err := t.Topics[topic][j].decode(pd, version); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (a *TxnOffsetCommitResponse) key() int16 {
+	return 28
+}
+
+func (a *TxnOffsetCommitResponse) version() int16 {
+	return 0
+}
+
+func (a *TxnOffsetCommitResponse) requiredVersion() KafkaVersion {
+	return V0_11_0_0
+}
diff --git a/vendor/github.com/Shopify/sarama/utils.go b/vendor/github.com/Shopify/sarama/utils.go
new file mode 100644
index 0000000..9392793
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/utils.go
@@ -0,0 +1,227 @@
+package sarama
+
+import (
+	"bufio"
+	"fmt"
+	"net"
+	"regexp"
+)
+
+type none struct{}
+
+// make []int32 sortable so we can sort partition numbers
+type int32Slice []int32
+
+func (slice int32Slice) Len() int {
+	return len(slice)
+}
+
+func (slice int32Slice) Less(i, j int) bool {
+	return slice[i] < slice[j]
+}
+
+func (slice int32Slice) Swap(i, j int) {
+	slice[i], slice[j] = slice[j], slice[i]
+}
+
+func dupInt32Slice(input []int32) []int32 {
+	ret := make([]int32, 0, len(input))
+	for _, val := range input {
+		ret = append(ret, val)
+	}
+	return ret
+}
+
+func withRecover(fn func()) {
+	defer func() {
+		handler := PanicHandler
+		if handler != nil {
+			if err := recover(); err != nil {
+				handler(err)
+			}
+		}
+	}()
+
+	fn()
+}
+
+func safeAsyncClose(b *Broker) {
+	tmp := b // local var prevents clobbering in goroutine
+	go withRecover(func() {
+		if connected, _ := tmp.Connected(); connected {
+			if err := tmp.Close(); err != nil {
+				Logger.Println("Error closing broker", tmp.ID(), ":", err)
+			}
+		}
+	})
+}
+
+// Encoder is a simple interface for any type that can be encoded as an array of bytes
+// in order to be sent as the key or value of a Kafka message. Length() is provided as an
+// optimization, and must return the same as len() on the result of Encode().
+type Encoder interface {
+	Encode() ([]byte, error)
+	Length() int
+}
+
+// make strings and byte slices encodable for convenience so they can be used as keys
+// and/or values in kafka messages
+
+// StringEncoder implements the Encoder interface for Go strings so that they can be used
+// as the Key or Value in a ProducerMessage.
+type StringEncoder string
+
+func (s StringEncoder) Encode() ([]byte, error) {
+	return []byte(s), nil
+}
+
+func (s StringEncoder) Length() int {
+	return len(s)
+}
+
+// ByteEncoder implements the Encoder interface for Go byte slices so that they can be used
+// as the Key or Value in a ProducerMessage.
+type ByteEncoder []byte
+
+func (b ByteEncoder) Encode() ([]byte, error) {
+	return b, nil
+}
+
+func (b ByteEncoder) Length() int {
+	return len(b)
+}
+
+// bufConn wraps a net.Conn with a buffer for reads to reduce the number of
+// reads that trigger syscalls.
+type bufConn struct {
+	net.Conn
+	buf *bufio.Reader
+}
+
+func newBufConn(conn net.Conn) *bufConn {
+	return &bufConn{
+		Conn: conn,
+		buf:  bufio.NewReader(conn),
+	}
+}
+
+func (bc *bufConn) Read(b []byte) (n int, err error) {
+	return bc.buf.Read(b)
+}
+
+// KafkaVersion instances represent versions of the upstream Kafka broker.
+type KafkaVersion struct {
+	// it's a struct rather than just typing the array directly to make it opaque and stop people
+	// generating their own arbitrary versions
+	version [4]uint
+}
+
+func newKafkaVersion(major, minor, veryMinor, patch uint) KafkaVersion {
+	return KafkaVersion{
+		version: [4]uint{major, minor, veryMinor, patch},
+	}
+}
+
+// IsAtLeast return true if and only if the version it is called on is
+// greater than or equal to the version passed in:
+//    V1.IsAtLeast(V2) // false
+//    V2.IsAtLeast(V1) // true
+func (v KafkaVersion) IsAtLeast(other KafkaVersion) bool {
+	for i := range v.version {
+		if v.version[i] > other.version[i] {
+			return true
+		} else if v.version[i] < other.version[i] {
+			return false
+		}
+	}
+	return true
+}
+
+// Effective constants defining the supported kafka versions.
+var (
+	V0_8_2_0  = newKafkaVersion(0, 8, 2, 0)
+	V0_8_2_1  = newKafkaVersion(0, 8, 2, 1)
+	V0_8_2_2  = newKafkaVersion(0, 8, 2, 2)
+	V0_9_0_0  = newKafkaVersion(0, 9, 0, 0)
+	V0_9_0_1  = newKafkaVersion(0, 9, 0, 1)
+	V0_10_0_0 = newKafkaVersion(0, 10, 0, 0)
+	V0_10_0_1 = newKafkaVersion(0, 10, 0, 1)
+	V0_10_1_0 = newKafkaVersion(0, 10, 1, 0)
+	V0_10_1_1 = newKafkaVersion(0, 10, 1, 1)
+	V0_10_2_0 = newKafkaVersion(0, 10, 2, 0)
+	V0_10_2_1 = newKafkaVersion(0, 10, 2, 1)
+	V0_11_0_0 = newKafkaVersion(0, 11, 0, 0)
+	V0_11_0_1 = newKafkaVersion(0, 11, 0, 1)
+	V0_11_0_2 = newKafkaVersion(0, 11, 0, 2)
+	V1_0_0_0  = newKafkaVersion(1, 0, 0, 0)
+	V1_1_0_0  = newKafkaVersion(1, 1, 0, 0)
+	V1_1_1_0  = newKafkaVersion(1, 1, 1, 0)
+	V2_0_0_0  = newKafkaVersion(2, 0, 0, 0)
+	V2_0_1_0  = newKafkaVersion(2, 0, 1, 0)
+	V2_1_0_0  = newKafkaVersion(2, 1, 0, 0)
+	V2_2_0_0  = newKafkaVersion(2, 2, 0, 0)
+	V2_3_0_0  = newKafkaVersion(2, 3, 0, 0)
+	V2_4_0_0  = newKafkaVersion(2, 4, 0, 0)
+
+	SupportedVersions = []KafkaVersion{
+		V0_8_2_0,
+		V0_8_2_1,
+		V0_8_2_2,
+		V0_9_0_0,
+		V0_9_0_1,
+		V0_10_0_0,
+		V0_10_0_1,
+		V0_10_1_0,
+		V0_10_1_1,
+		V0_10_2_0,
+		V0_10_2_1,
+		V0_11_0_0,
+		V0_11_0_1,
+		V0_11_0_2,
+		V1_0_0_0,
+		V1_1_0_0,
+		V1_1_1_0,
+		V2_0_0_0,
+		V2_0_1_0,
+		V2_1_0_0,
+		V2_2_0_0,
+		V2_3_0_0,
+		V2_4_0_0,
+	}
+	MinVersion = V0_8_2_0
+	MaxVersion = V2_4_0_0
+)
+
+//ParseKafkaVersion parses and returns kafka version or error from a string
+func ParseKafkaVersion(s string) (KafkaVersion, error) {
+	if len(s) < 5 {
+		return MinVersion, fmt.Errorf("invalid version `%s`", s)
+	}
+	var major, minor, veryMinor, patch uint
+	var err error
+	if s[0] == '0' {
+		err = scanKafkaVersion(s, `^0\.\d+\.\d+\.\d+$`, "0.%d.%d.%d", [3]*uint{&minor, &veryMinor, &patch})
+	} else {
+		err = scanKafkaVersion(s, `^\d+\.\d+\.\d+$`, "%d.%d.%d", [3]*uint{&major, &minor, &veryMinor})
+	}
+	if err != nil {
+		return MinVersion, err
+	}
+	return newKafkaVersion(major, minor, veryMinor, patch), nil
+}
+
+func scanKafkaVersion(s string, pattern string, format string, v [3]*uint) error {
+	if !regexp.MustCompile(pattern).MatchString(s) {
+		return fmt.Errorf("invalid version `%s`", s)
+	}
+	_, err := fmt.Sscanf(s, format, v[0], v[1], v[2])
+	return err
+}
+
+func (v KafkaVersion) String() string {
+	if v.version[0] == 0 {
+		return fmt.Sprintf("0.%d.%d.%d", v.version[1], v.version[2], v.version[3])
+	}
+
+	return fmt.Sprintf("%d.%d.%d", v.version[0], v.version[1], v.version[2])
+}
diff --git a/vendor/github.com/Shopify/sarama/zstd.go b/vendor/github.com/Shopify/sarama/zstd.go
new file mode 100644
index 0000000..58880e2
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/zstd.go
@@ -0,0 +1,27 @@
+package sarama
+
+import (
+	"github.com/klauspost/compress/zstd"
+	"sync"
+)
+
+var (
+	zstdDec *zstd.Decoder
+	zstdEnc *zstd.Encoder
+
+	zstdEncOnce, zstdDecOnce sync.Once
+)
+
+func zstdDecompress(dst, src []byte) ([]byte, error) {
+	zstdDecOnce.Do(func() {
+		zstdDec, _ = zstd.NewReader(nil)
+	})
+	return zstdDec.DecodeAll(src, dst)
+}
+
+func zstdCompress(dst, src []byte) ([]byte, error) {
+	zstdEncOnce.Do(func() {
+		zstdEnc, _ = zstd.NewWriter(nil, zstd.WithZeroFrames(true))
+	})
+	return zstdEnc.EncodeAll(src, dst), nil
+}