From f786b6ba161222bd76af576ad09b04163b8371a1 Mon Sep 17 00:00:00 2001
From: Gyuho Lee <leegyuho@amazon.com>
Date: Thu, 8 Aug 2019 13:04:38 -0700
Subject: [PATCH] etcdserver: add
 "etcd_server_snapshot_apply_in_progress_total"

Signed-off-by: Gyuho Lee <leegyuho@amazon.com>
---
 etcdserver/metrics.go | 7 +++++++
 etcdserver/server.go  | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/etcdserver/metrics.go b/etcdserver/metrics.go
index a868331fb..e7f4a3747 100644
--- a/etcdserver/metrics.go
+++ b/etcdserver/metrics.go
@@ -76,6 +76,12 @@ var (
 		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",
@@ -153,6 +159,7 @@ func init() {
 	prometheus.MustRegister(leaderChanges)
 	prometheus.MustRegister(heartbeatSendFailures)
 	prometheus.MustRegister(slowApplies)
+	prometheus.MustRegister(applySnapshotInProgress)
 	prometheus.MustRegister(proposalsCommitted)
 	prometheus.MustRegister(proposalsApplied)
 	prometheus.MustRegister(proposalsPending)
diff --git a/etcdserver/server.go b/etcdserver/server.go
index 81ed45afe..76b802b2e 100644
--- a/etcdserver/server.go
+++ b/etcdserver/server.go
@@ -1113,6 +1113,7 @@ func (s *EtcdServer) applySnapshot(ep *etcdProgress, apply *apply) {
 	if raft.IsEmptySnap(apply.snapshot) {
 		return
 	}
+	applySnapshotInProgress.Inc()
 
 	lg := s.getLogger()
 	if lg != nil {
@@ -1138,6 +1139,7 @@ func (s *EtcdServer) applySnapshot(ep *etcdProgress, apply *apply) {
 		} else {
 			plog.Infof("finished applying incoming snapshot at index %d", ep.snapi)
 		}
+		applySnapshotInProgress.Dec()
 	}()
 
 	if apply.snapshot.Metadata.Index <= ep.appliedi {