diff --git a/vendor/go.etcd.io/etcd/etcdserver/metrics.go b/vendor/go.etcd.io/etcd/etcdserver/metrics.go
new file mode 100644
index 0000000..e0c0cde
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/metrics.go
@@ -0,0 +1,221 @@
+// 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 etcdserver
+
+import (
+	goruntime "runtime"
+	"time"
+
+	"go.etcd.io/etcd/pkg/runtime"
+	"go.etcd.io/etcd/version"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"go.uber.org/zap"
+)
+
+var (
+	hasLeader = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "has_leader",
+		Help:      "Whether or not a leader exists. 1 is existence, 0 is not.",
+	})
+	isLeader = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "is_leader",
+		Help:      "Whether or not this member is a leader. 1 if is, 0 otherwise.",
+	})
+	leaderChanges = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "leader_changes_seen_total",
+		Help:      "The number of leader changes seen.",
+	})
+	isLearner = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "is_learner",
+		Help:      "Whether or not this member is a learner. 1 if is, 0 otherwise.",
+	})
+	learnerPromoteFailed = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "learner_promote_failures",
+		Help:      "The total number of failed learner promotions (likely learner not ready) while this member is leader.",
+	},
+		[]string{"Reason"},
+	)
+	learnerPromoteSucceed = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "learner_promote_successes",
+		Help:      "The total number of successful learner promotions while this member is leader.",
+	})
+	heartbeatSendFailures = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "heartbeat_send_failures_total",
+		Help:      "The total number of leader heartbeat send failures (likely overloaded from slow disk).",
+	})
+	slowApplies = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "slow_apply_total",
+		Help:      "The total number of slow apply requests (likely overloaded from slow disk).",
+	})
+	applySnapshotInProgress = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "snapshot_apply_in_progress_total",
+		Help:      "1 if the server is applying the incoming snapshot. 0 if none.",
+	})
+	proposalsCommitted = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "proposals_committed_total",
+		Help:      "The total number of consensus proposals committed.",
+	})
+	proposalsApplied = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "proposals_applied_total",
+		Help:      "The total number of consensus proposals applied.",
+	})
+	proposalsPending = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "proposals_pending",
+		Help:      "The current number of pending proposals to commit.",
+	})
+	proposalsFailed = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "proposals_failed_total",
+		Help:      "The total number of failed proposals seen.",
+	})
+	slowReadIndex = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "slow_read_indexes_total",
+		Help:      "The total number of pending read indexes not in sync with leader's or timed out read index requests.",
+	})
+	readIndexFailed = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "read_indexes_failed_total",
+		Help:      "The total number of failed read indexes seen.",
+	})
+	leaseExpired = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "server",
+		Name:      "lease_expired_total",
+		Help:      "The total number of expired leases.",
+	})
+	quotaBackendBytes = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "quota_backend_bytes",
+		Help:      "Current backend storage quota size in bytes.",
+	})
+	currentVersion = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "version",
+		Help:      "Which version is running. 1 for 'server_version' label with current version.",
+	},
+		[]string{"server_version"})
+	currentGoVersion = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "go_version",
+		Help:      "Which Go version server is running with. 1 for 'server_go_version' label with current version.",
+	},
+		[]string{"server_go_version"})
+	serverID = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "id",
+		Help:      "Server or member ID in hexadecimal format. 1 for 'server_id' label with current ID.",
+	},
+		[]string{"server_id"})
+)
+
+func init() {
+	prometheus.MustRegister(hasLeader)
+	prometheus.MustRegister(isLeader)
+	prometheus.MustRegister(leaderChanges)
+	prometheus.MustRegister(heartbeatSendFailures)
+	prometheus.MustRegister(slowApplies)
+	prometheus.MustRegister(applySnapshotInProgress)
+	prometheus.MustRegister(proposalsCommitted)
+	prometheus.MustRegister(proposalsApplied)
+	prometheus.MustRegister(proposalsPending)
+	prometheus.MustRegister(proposalsFailed)
+	prometheus.MustRegister(slowReadIndex)
+	prometheus.MustRegister(readIndexFailed)
+	prometheus.MustRegister(leaseExpired)
+	prometheus.MustRegister(quotaBackendBytes)
+	prometheus.MustRegister(currentVersion)
+	prometheus.MustRegister(currentGoVersion)
+	prometheus.MustRegister(serverID)
+	prometheus.MustRegister(isLearner)
+	prometheus.MustRegister(learnerPromoteSucceed)
+	prometheus.MustRegister(learnerPromoteFailed)
+
+	currentVersion.With(prometheus.Labels{
+		"server_version": version.Version,
+	}).Set(1)
+	currentGoVersion.With(prometheus.Labels{
+		"server_go_version": goruntime.Version(),
+	}).Set(1)
+}
+
+func monitorFileDescriptor(lg *zap.Logger, done <-chan struct{}) {
+	ticker := time.NewTicker(5 * time.Second)
+	defer ticker.Stop()
+	for {
+		used, err := runtime.FDUsage()
+		if err != nil {
+			if lg != nil {
+				lg.Warn("failed to get file descriptor usage", zap.Error(err))
+			} else {
+				plog.Errorf("cannot monitor file descriptor usage (%v)", err)
+			}
+			return
+		}
+		limit, err := runtime.FDLimit()
+		if err != nil {
+			if lg != nil {
+				lg.Warn("failed to get file descriptor limit", zap.Error(err))
+			} else {
+				plog.Errorf("cannot monitor file descriptor usage (%v)", err)
+			}
+			return
+		}
+		if used >= limit/5*4 {
+			if lg != nil {
+				lg.Warn("80% of file descriptors are used", zap.Uint64("used", used), zap.Uint64("limit", limit))
+			} else {
+				plog.Warningf("80%% of the file descriptor limit is used [used = %d, limit = %d]", used, limit)
+			}
+		}
+		select {
+		case <-ticker.C:
+		case <-done:
+			return
+		}
+	}
+}