mvcc: add "etcd_mvcc_put_size_in_bytes" to monitor the throughput of put request.

mvcc/metrics.go

@@ -296,6 +296,14 @@ var (
 	// overridden by mvcc initialization
 	reportCompactRevMu sync.RWMutex
 	reportCompactRev   = func() float64 { return 0 }
+
+	putSizeGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd",
+			Subsystem: "mvcc",
+			Name:      "put_size_in_bytes",
+			Help:      "The total size of put kv pairs seen by this member.",
+		})
 )
 
 func init() {
@@ -325,6 +333,7 @@ func init() {
 	prometheus.MustRegister(hashRevSec)
 	prometheus.MustRegister(currentRev)
 	prometheus.MustRegister(compactRev)
+	prometheus.MustRegister(putSizeGauge)
 }
 
 // ReportEventReceived reports that an event is received.

mvcc/metrics_txn.go

@@ -21,14 +21,15 @@ type metricsTxnWrite struct {
 	ranges  uint
 	puts    uint
 	deletes uint
+	putSize int64
 }
 
 func newMetricsTxnRead(tr TxnRead) TxnRead {
-	return &metricsTxnWrite{&txnReadWrite{tr}, 0, 0, 0}
+	return &metricsTxnWrite{&txnReadWrite{tr}, 0, 0, 0, 0}
 }
 
 func newMetricsTxnWrite(tw TxnWrite) TxnWrite {
-	return &metricsTxnWrite{tw, 0, 0, 0}
+	return &metricsTxnWrite{tw, 0, 0, 0, 0}
 }
 
 func (tw *metricsTxnWrite) Range(key, end []byte, ro RangeOptions) (*RangeResult, error) {
@@ -43,6 +44,8 @@ func (tw *metricsTxnWrite) DeleteRange(key, end []byte) (n, rev int64) {
 
 func (tw *metricsTxnWrite) Put(key, value []byte, lease lease.LeaseID) (rev int64) {
 	tw.puts++
+	size := int64(len(key) + len(value))
+	tw.putSize += size
 	return tw.TxnWrite.Put(key, value, lease)
 }
 
@@ -60,6 +63,7 @@ func (tw *metricsTxnWrite) End() {
 	puts := float64(tw.puts)
 	putCounter.Add(puts)
 	putCounterDebug.Add(puts) // TODO: remove in 3.5 release
+	putSizeGauge.Add(float64(tw.putSize))
 
 	deletes := float64(tw.deletes)
 	deleteCounter.Add(deletes)