diff --git a/vendor/github.com/Shopify/sarama/client.go b/vendor/github.com/Shopify/sarama/client.go
new file mode 100644
index 0000000..c0918ba
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/client.go
@@ -0,0 +1,1112 @@
+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. It will return a
+	// locally cached value if it's available. You can call RefreshController
+	// to update the cached value. Requires Kafka 0.10 or higher.
+	Controller() (*Broker, error)
+
+	// RefreshController retrieves the cluster controller from fresh metadata
+	// and stores it in the local cache. Requires Kafka 0.10 or higher.
+	RefreshController() (*Broker, error)
+
+	// Brokers returns the current set of active brokers as retrieved from cluster metadata.
+	Brokers() []*Broker
+
+	// Broker returns the active Broker if available for the broker ID.
+	Broker(brokerID int32) (*Broker, error)
+
+	// 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)
+
+	// RefreshBrokers takes a list of addresses to be used as seed brokers.
+	// Existing broker connections are closed and the updated list of seed brokers
+	// will be used for the next metadata fetch.
+	RefreshBrokers(addrs []string) 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),
+	}
+
+	client.randomizeSeedBrokers(addrs)
+
+	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) Broker(brokerID int32) (*Broker, error) {
+	client.lock.RLock()
+	defer client.lock.RUnlock()
+	broker, ok := client.brokers[brokerID]
+	if !ok {
+		return nil, ErrBrokerNotFound
+	}
+	_ = broker.Open(client.conf)
+	return broker, nil
+}
+
+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) RefreshBrokers(addrs []string) error {
+	if client.Closed() {
+		return ErrClosedClient
+	}
+
+	client.lock.Lock()
+	defer client.lock.Unlock()
+
+	for _, broker := range client.brokers {
+		_ = broker.Close()
+		delete(client.brokers, broker.ID())
+	}
+
+	client.seedBrokers = nil
+	client.deadSeeds = nil
+
+	client.randomizeSeedBrokers(addrs)
+
+	return nil
+}
+
+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 topic == "" {
+			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
+}
+
+// deregisterController removes the cached controllerID
+func (client *client) deregisterController() {
+	client.lock.Lock()
+	defer client.lock.Unlock()
+	delete(client.brokers, client.controllerID)
+}
+
+// RefreshController retrieves the cluster controller from fresh metadata
+// and stores it in the local cache. Requires Kafka 0.10 or higher.
+func (client *client) RefreshController() (*Broker, error) {
+	if client.Closed() {
+		return nil, ErrClosedClient
+	}
+
+	client.deregisterController()
+
+	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
+
+func (client *client) randomizeSeedBrokers(addrs []string) {
+	random := rand.New(rand.NewSource(time.Now().UnixNano()))
+	for _, index := range random.Perm(len(addrs)) {
+		client.seedBrokers = append(client.seedBrokers, NewBroker(addrs[index]))
+	}
+}
+
+func (client *client) updateBroker(brokers []*Broker) {
+	currentBroker := make(map[int32]*Broker, len(brokers))
+
+	for _, broker := range brokers {
+		currentBroker[broker.ID()] = broker
+		if client.brokers[broker.ID()] == nil { // add new broker
+			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() { // replace broker with new address
+			safeAsyncClose(client.brokers[broker.ID()])
+			client.brokers[broker.ID()] = broker
+			Logger.Printf("client/brokers replaced registered broker #%d with %s", broker.ID(), broker.Addr())
+		}
+	}
+
+	for id, broker := range client.brokers {
+		if _, exist := currentBroker[id]; !exist { // remove old broker
+			safeAsyncClose(broker)
+			delete(client.brokers, id)
+			Logger.Printf("client/broker remove invalid broker #%d with %s", broker.ID(), broker.Addr())
+		}
+	}
+}
+
+// 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 {
+	var 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", 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 := 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 == ErrSASLAuthenticationFailed {
+				Logger.Println("client/metadata failed SASL authentication")
+				return err
+			}
+
+			if err == 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
+	// - if some brokers is not exist in it, remove old broker
+	// - otherwise ignore it, replacing our existing one would just bounce the connection
+	client.updateBroker(data.Brokers)
+
+	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
+}