metrics: add statement deadlock detect duration (#14444) (#14484)

pingcap · Jan 16, 2020 · 1c279e9 · 1c279e9
1 parent 0d84245
commit 1c279e9
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Showing 3 changed files with 19 additions and 0 deletions.
diff --git a/executor/adapter.go b/executor/adapter.go
@@ -442,6 +442,7 @@ func (a *ExecStmt) handlePessimisticDML(ctx context.Context, e Executor) error {
 	}
 	txnCtx := sctx.GetSessionVars().TxnCtx
 	for {
+		startPointGetLocking := time.Now()
 		_, err = a.handleNoDelayExecutor(ctx, e)
 		if !txn.Valid() {
 			return err
@@ -450,6 +451,9 @@ func (a *ExecStmt) handlePessimisticDML(ctx context.Context, e Executor) error {
 			// It is possible the DML has point get plan that locks the key.
 			e, err = a.handlePessimisticLockError(ctx, err)
 			if err != nil {
+				if ErrDeadlock.Equal(err) {
+					metrics.StatementDeadlockDetectDuration.Observe(time.Since(startPointGetLocking).Seconds())
+				}
 				return err
 			}
 			continue
@@ -464,12 +468,16 @@ func (a *ExecStmt) handlePessimisticDML(ctx context.Context, e Executor) error {
 		}
 		seVars := sctx.GetSessionVars()
 		lockCtx := newLockCtx(seVars, seVars.LockWaitTimeout)
+		startLocking := time.Now()
 		err = txn.LockKeys(ctx, lockCtx, keys...)
 		if err == nil {
 			return nil
 		}
 		e, err = a.handlePessimisticLockError(ctx, err)
 		if err != nil {
+			if ErrDeadlock.Equal(err) {
+				metrics.StatementDeadlockDetectDuration.Observe(time.Since(startLocking).Seconds())
+			}
 			return err
 		}
 	}

diff --git a/metrics/metrics.go b/metrics/metrics.go
@@ -133,6 +133,7 @@ func RegisterMetrics() {
 	prometheus.MustRegister(TimeJumpBackCounter)
 	prometheus.MustRegister(TransactionCounter)
 	prometheus.MustRegister(TransactionDuration)
+	prometheus.MustRegister(StatementDeadlockDetectDuration)
 	prometheus.MustRegister(UpdateSelfVersionHistogram)
 	prometheus.MustRegister(UpdateStatsCounter)
 	prometheus.MustRegister(WatchOwnerCounter)

diff --git a/metrics/session.go b/metrics/session.go
@@ -97,6 +97,16 @@ var (
 			Help:      "Bucketed histogram of a transaction execution duration, including retry.",
 			Buckets:   prometheus.ExponentialBuckets(0.001, 2, 20), // 1ms ~ 1049s
 		}, []string{LblSQLType, LblType})
+
+	StatementDeadlockDetectDuration = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: "tidb",
+			Subsystem: "session",
+			Name:      "statement_deadlock_detect_duration_seconds",
+			Help:      "Bucketed histogram of a statement deadlock detect duration.",
+			Buckets:   prometheus.ExponentialBuckets(0.001, 2, 20), // 1ms ~ 1049s
+		},
+	)
 )
 
 // Label constants.