mvcc/backend: clean up histogram variables

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

mvcc/backend/backend.go

@@ -230,8 +230,9 @@ func (b *backend) Snapshot() Snapshot {
 				} else {
 					plog.Warningf("snapshotting is taking more than %v seconds to finish transferring %v MB [started at %v]", time.Since(start).Seconds(), float64(dbBytes)/float64(1024*1014), start)
 				}
+
 			case <-stopc:
-				snapshotDurations.Observe(time.Since(start).Seconds())
+				snapshotTransferSec.Observe(time.Since(start).Seconds())
 				return
 			}
 		}
@@ -416,7 +417,7 @@ func (b *backend) defrag() error {
 	atomic.StoreInt64(&b.sizeInUse, size-(int64(db.Stats().FreePageN)*int64(db.Info().PageSize)))
 
 	took := time.Since(now)
-	defragDurations.Observe(took.Seconds())
+	defragSec.Observe(took.Seconds())
 
 	size2, sizeInUse2 := b.Size(), b.SizeInUse()
 	if b.lg != nil {

mvcc/backend/batch_tx.go

@@ -220,7 +220,7 @@ func (t *batchTx) commit(stop bool) {
 		err := t.tx.Commit()
 		// gofail: var afterCommit struct{}
 
-		commitDurations.Observe(time.Since(start).Seconds())
+		commitSec.Observe(time.Since(start).Seconds())
 		atomic.AddInt64(&t.backend.commits, 1)
 
 		t.pending = 0

mvcc/backend/metrics.go

@@ -17,7 +17,7 @@ package backend
 import "github.com/prometheus/client_golang/prometheus"
 
 var (
-	commitDurations = prometheus.NewHistogram(prometheus.HistogramOpts{
+	commitSec = prometheus.NewHistogram(prometheus.HistogramOpts{
 		Namespace: "etcd",
 		Subsystem: "disk",
 		Name:      "backend_commit_duration_seconds",
@@ -28,7 +28,7 @@ var (
 		Buckets: prometheus.ExponentialBuckets(0.001, 2, 14),
 	})
 
-	defragDurations = prometheus.NewHistogram(prometheus.HistogramOpts{
+	defragSec = prometheus.NewHistogram(prometheus.HistogramOpts{
 		Namespace: "etcd",
 		Subsystem: "disk",
 		Name:      "backend_defrag_duration_seconds",
@@ -40,7 +40,7 @@ var (
 		Buckets: prometheus.ExponentialBuckets(.1, 2, 13),
 	})
 
-	snapshotDurations = prometheus.NewHistogram(prometheus.HistogramOpts{
+	snapshotTransferSec = prometheus.NewHistogram(prometheus.HistogramOpts{
 		Namespace: "etcd",
 		Subsystem: "disk",
 		Name:      "backend_snapshot_duration_seconds",
@@ -53,7 +53,7 @@ var (
 )
 
 func init() {
-	prometheus.MustRegister(commitDurations)
-	prometheus.MustRegister(defragDurations)
-	prometheus.MustRegister(snapshotDurations)
+	prometheus.MustRegister(commitSec)
+	prometheus.MustRegister(defragSec)
+	prometheus.MustRegister(snapshotTransferSec)
 }