ethdb: add write delay meters

ethdb/database.go

@@ -30,6 +30,7 @@ import (
 	"github.com/syndtr/goleveldb/leveldb/iterator"
 	"github.com/syndtr/goleveldb/leveldb/opt"
 
+	"fmt"
 	gometrics "github.com/rcrowley/go-metrics"
 )
 
@@ -42,9 +43,11 @@ type LDBDatabase struct {
 	getTimer        gometrics.Timer // Timer for measuring the database get request counts and latencies
 	putTimer        gometrics.Timer // Timer for measuring the database put request counts and latencies
 	delTimer        gometrics.Timer // Timer for measuring the database delete request counts and latencies
+	writeDelayTimer gometrics.Timer // Timer for measuring the write delay duration due to database compaction
 	missMeter       gometrics.Meter // Meter for measuring the missed database get requests
 	readMeter       gometrics.Meter // Meter for measuring the database get request data usage
 	writeMeter      gometrics.Meter // Meter for measuring the database put request data usage
+	writeDelayMeter gometrics.Meter // Meter for measuring the write delay number due to database compaction
 	compTimeMeter   gometrics.Meter // Meter for measuring the total time spent in database compaction
 	compReadMeter   gometrics.Meter // Meter for measuring the data read during compaction
 	compWriteMeter  gometrics.Meter // Meter for measuring the data written during compaction
@@ -186,6 +189,9 @@ func (db *LDBDatabase) Meter(prefix string) {
 	db.missMeter = metrics.NewMeter(prefix + "user/misses")
 	db.readMeter = metrics.NewMeter(prefix + "user/reads")
 	db.writeMeter = metrics.NewMeter(prefix + "user/writes")
+
+	db.writeDelayTimer = metrics.NewTimer(prefix + "compact/writedelay/duration")
+	db.writeDelayMeter = metrics.NewMeter(prefix + "compact/writedelay/counter")
 	db.compTimeMeter = metrics.NewMeter(prefix + "compact/time")
 	db.compReadMeter = metrics.NewMeter(prefix + "compact/input")
 	db.compWriteMeter = metrics.NewMeter(prefix + "compact/output")
@@ -213,7 +219,7 @@ func (db *LDBDatabase) meter(refresh time.Duration) {
 	// Create the counters to store current and previous values
 	counters := make([][]float64, 2)
 	for i := 0; i < 2; i++ {
-		counters[i] = make([]float64, 3)
+		counters[i] = make([]float64, 5)
 	}
 	// Iterate ad infinitum and collect the stats
 	for i := 1; ; i++ {
@@ -262,6 +268,23 @@ func (db *LDBDatabase) meter(refresh time.Duration) {
 		if db.compWriteMeter != nil {
 			db.compWriteMeter.Mark(int64((counters[i%2][2] - counters[(i-1)%2][2]) * 1024 * 1024))
 		}
+
+		// Stat write delay.
+		writeDelay, err := db.db.GetProperty("leveldb.writedelay")
+		if err != nil {
+			db.log.Error("Failed to read database write delay statistic", "err", err)
+			return
+		}
+		if n, err := fmt.Sscanf(writeDelay, "DelayN: %f Delay(sec):%.5f", &counters[i%2][3], &counters[i%2][4]); n != 2 || err != nil {
+			db.log.Error("Write delay statistic not found")
+			return
+		}
+		if db.writeDelayTimer != nil {
+			db.writeDelayTimer.Update(time.Duration(int64((counters[i%2][4] - counters[(i-1)%2][4]) * 1000 * 1000 * 1000)))
+		}
+		if db.writeDelayMeter != nil {
+			db.writeDelayMeter.Mark(int64((counters[i%2][3] - counters[(i-1)%2][3])))
+		}
 		// Sleep a bit, then repeat the stats collection
 		select {
 		case errc := <-db.quitChan: