diff --git a/vendor/go.etcd.io/etcd/mvcc/metrics.go b/vendor/go.etcd.io/etcd/mvcc/metrics.go
new file mode 100644
index 0000000..7526ee4
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/metrics.go
@@ -0,0 +1,336 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"sync"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	rangeCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "mvcc",
+			Name:      "range_total",
+			Help:      "Total number of ranges seen by this member.",
+		})
+	rangeCounterDebug = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "range_total",
+			Help:      "Total number of ranges seen by this member.",
+		})
+
+	putCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "mvcc",
+			Name:      "put_total",
+			Help:      "Total number of puts seen by this member.",
+		})
+	// TODO: remove in 3.5 release
+	putCounterDebug = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "put_total",
+			Help:      "Total number of puts seen by this member.",
+		})
+
+	deleteCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "mvcc",
+			Name:      "delete_total",
+			Help:      "Total number of deletes seen by this member.",
+		})
+	// TODO: remove in 3.5 release
+	deleteCounterDebug = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "delete_total",
+			Help:      "Total number of deletes seen by this member.",
+		})
+
+	txnCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "mvcc",
+			Name:      "txn_total",
+			Help:      "Total number of txns seen by this member.",
+		})
+	txnCounterDebug = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "txn_total",
+			Help:      "Total number of txns seen by this member.",
+		})
+
+	keysGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "keys_total",
+			Help:      "Total number of keys.",
+		})
+
+	watchStreamGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "watch_stream_total",
+			Help:      "Total number of watch streams.",
+		})
+
+	watcherGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "watcher_total",
+			Help:      "Total number of watchers.",
+		})
+
+	slowWatcherGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "slow_watcher_total",
+			Help:      "Total number of unsynced slow watchers.",
+		})
+
+	totalEventsCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "events_total",
+			Help:      "Total number of events sent by this member.",
+		})
+
+	pendingEventsGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "pending_events_total",
+			Help:      "Total number of pending events to be sent.",
+		})
+
+	indexCompactionPauseMs = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "index_compaction_pause_duration_milliseconds",
+			Help:      "Bucketed histogram of index compaction pause duration.",
+
+			// lowest bucket start of upper bound 0.5 ms with factor 2
+			// highest bucket start of 0.5 ms * 2^13 == 4.096 sec
+			Buckets: prometheus.ExponentialBuckets(0.5, 2, 14),
+		})
+
+	dbCompactionPauseMs = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "db_compaction_pause_duration_milliseconds",
+			Help:      "Bucketed histogram of db compaction pause duration.",
+
+			// lowest bucket start of upper bound 1 ms with factor 2
+			// highest bucket start of 1 ms * 2^12 == 4.096 sec
+			Buckets: prometheus.ExponentialBuckets(1, 2, 13),
+		})
+
+	dbCompactionTotalMs = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "db_compaction_total_duration_milliseconds",
+			Help:      "Bucketed histogram of db compaction total duration.",
+
+			// lowest bucket start of upper bound 100 ms with factor 2
+			// highest bucket start of 100 ms * 2^13 == 8.192 sec
+			Buckets: prometheus.ExponentialBuckets(100, 2, 14),
+		})
+
+	dbCompactionKeysCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "db_compaction_keys_total",
+			Help:      "Total number of db keys compacted.",
+		})
+
+	dbTotalSize = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "mvcc",
+		Name:      "db_total_size_in_bytes",
+		Help:      "Total size of the underlying database physically allocated in bytes.",
+	},
+		func() float64 {
+			reportDbTotalSizeInBytesMu.RLock()
+			defer reportDbTotalSizeInBytesMu.RUnlock()
+			return reportDbTotalSizeInBytes()
+		},
+	)
+	// overridden by mvcc initialization
+	reportDbTotalSizeInBytesMu sync.RWMutex
+	reportDbTotalSizeInBytes   = func() float64 { return 0 }
+
+	// TODO: remove this in v3.5
+	dbTotalSizeDebug = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "mvcc",
+		Name:      "db_total_size_in_bytes",
+		Help:      "Total size of the underlying database physically allocated in bytes.",
+	},
+		func() float64 {
+			reportDbTotalSizeInBytesDebugMu.RLock()
+			defer reportDbTotalSizeInBytesDebugMu.RUnlock()
+			return reportDbTotalSizeInBytesDebug()
+		},
+	)
+	// overridden by mvcc initialization
+	reportDbTotalSizeInBytesDebugMu sync.RWMutex
+	reportDbTotalSizeInBytesDebug   = func() float64 { return 0 }
+
+	dbTotalSizeInUse = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "mvcc",
+		Name:      "db_total_size_in_use_in_bytes",
+		Help:      "Total size of the underlying database logically in use in bytes.",
+	},
+		func() float64 {
+			reportDbTotalSizeInUseInBytesMu.RLock()
+			defer reportDbTotalSizeInUseInBytesMu.RUnlock()
+			return reportDbTotalSizeInUseInBytes()
+		},
+	)
+	// overridden by mvcc initialization
+	reportDbTotalSizeInUseInBytesMu sync.RWMutex
+	reportDbTotalSizeInUseInBytes   = func() float64 { return 0 }
+
+	dbOpenReadTxN = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "mvcc",
+		Name:      "db_open_read_transactions",
+		Help:      "The number of currently open read transactions",
+	},
+
+		func() float64 {
+			reportDbOpenReadTxNMu.RLock()
+			defer reportDbOpenReadTxNMu.RUnlock()
+			return reportDbOpenReadTxN()
+		},
+	)
+	// overridden by mvcc initialization
+	reportDbOpenReadTxNMu sync.RWMutex
+	reportDbOpenReadTxN   = func() float64 { return 0 }
+
+	hashSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "mvcc",
+		Name:      "hash_duration_seconds",
+		Help:      "The latency distribution of storage hash operation.",
+
+		// 100 MB usually takes 100 ms, so start with 10 MB of 10 ms
+		// lowest bucket start of upper bound 0.01 sec (10 ms) with factor 2
+		// highest bucket start of 0.01 sec * 2^14 == 163.84 sec
+		Buckets: prometheus.ExponentialBuckets(.01, 2, 15),
+	})
+
+	hashRevSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "mvcc",
+		Name:      "hash_rev_duration_seconds",
+		Help:      "The latency distribution of storage hash by revision operation.",
+
+		// 100 MB usually takes 100 ms, so start with 10 MB of 10 ms
+		// lowest bucket start of upper bound 0.01 sec (10 ms) with factor 2
+		// highest bucket start of 0.01 sec * 2^14 == 163.84 sec
+		Buckets: prometheus.ExponentialBuckets(.01, 2, 15),
+	})
+
+	currentRev = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "mvcc",
+		Name:      "current_revision",
+		Help:      "The current revision of store.",
+	},
+		func() float64 {
+			reportCurrentRevMu.RLock()
+			defer reportCurrentRevMu.RUnlock()
+			return reportCurrentRev()
+		},
+	)
+	// overridden by mvcc initialization
+	reportCurrentRevMu sync.RWMutex
+	reportCurrentRev   = func() float64 { return 0 }
+
+	compactRev = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "mvcc",
+		Name:      "compact_revision",
+		Help:      "The revision of the last compaction in store.",
+	},
+		func() float64 {
+			reportCompactRevMu.RLock()
+			defer reportCompactRevMu.RUnlock()
+			return reportCompactRev()
+		},
+	)
+	// overridden by mvcc initialization
+	reportCompactRevMu sync.RWMutex
+	reportCompactRev   = func() float64 { return 0 }
+)
+
+func init() {
+	prometheus.MustRegister(rangeCounter)
+	prometheus.MustRegister(rangeCounterDebug)
+	prometheus.MustRegister(putCounter)
+	prometheus.MustRegister(putCounterDebug)
+	prometheus.MustRegister(deleteCounter)
+	prometheus.MustRegister(deleteCounterDebug)
+	prometheus.MustRegister(txnCounter)
+	prometheus.MustRegister(txnCounterDebug)
+	prometheus.MustRegister(keysGauge)
+	prometheus.MustRegister(watchStreamGauge)
+	prometheus.MustRegister(watcherGauge)
+	prometheus.MustRegister(slowWatcherGauge)
+	prometheus.MustRegister(totalEventsCounter)
+	prometheus.MustRegister(pendingEventsGauge)
+	prometheus.MustRegister(indexCompactionPauseMs)
+	prometheus.MustRegister(dbCompactionPauseMs)
+	prometheus.MustRegister(dbCompactionTotalMs)
+	prometheus.MustRegister(dbCompactionKeysCounter)
+	prometheus.MustRegister(dbTotalSize)
+	prometheus.MustRegister(dbTotalSizeDebug)
+	prometheus.MustRegister(dbTotalSizeInUse)
+	prometheus.MustRegister(dbOpenReadTxN)
+	prometheus.MustRegister(hashSec)
+	prometheus.MustRegister(hashRevSec)
+	prometheus.MustRegister(currentRev)
+	prometheus.MustRegister(compactRev)
+}
+
+// ReportEventReceived reports that an event is received.
+// This function should be called when the external systems received an
+// event from mvcc.Watcher.
+func ReportEventReceived(n int) {
+	pendingEventsGauge.Sub(float64(n))
+	totalEventsCounter.Add(float64(n))
+}