From 7676a0968ccc4a24e316852ad9f278743d89092a Mon Sep 17 00:00:00 2001
From: wangleixin1 <wangleixin1@jd.com>
Date: Wed, 7 Aug 2024 20:01:43 +0800
Subject: [PATCH] feat: clear_metrics

---
 .../prometheusbackend/prometheusbackend.go    | 10 ++++
 go/vt/vtgate/scatter_conn.go                  | 47 +++++++++++++------
 go/vt/vtgate/vtgate.go                        | 17 +++++++
 3 files changed, 59 insertions(+), 15 deletions(-)

diff --git a/go/stats/prometheusbackend/prometheusbackend.go b/go/stats/prometheusbackend/prometheusbackend.go
index 62165e117c1..cadb86c3f2b 100644
--- a/go/stats/prometheusbackend/prometheusbackend.go
+++ b/go/stats/prometheusbackend/prometheusbackend.go
@@ -18,7 +18,9 @@ package prometheusbackend
 
 import (
 	"expvar"
+	"net/http"
 	"strings"
+	"vitess.io/vitess/go/vt/vtgate"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -41,8 +43,16 @@ var (
 func Init(namespace string) {
 	servenv.HTTPHandle("/metrics", promhttp.Handler())
 	be.namespace = namespace
+	servenv.HTTPHandleFunc("/clear/metrics", ClearMetricsHandler)
+
 	stats.Register(be.publishPrometheusMetric)
 }
+func ClearMetricsHandler(w http.ResponseWriter, r *http.Request) {
+
+	vtgate.ClearMetrics()
+	log.Infof("All vtgate Prometheus metrics have been cleared.")
+	w.Write([]byte("All vtgate  Prometheus metrics have been cleared."))
+}
 
 // publishPrometheusMetric is used to publish the metric to Prometheus.
 func (be PromBackend) publishPrometheusMetric(name string, v expvar.Var) {
diff --git a/go/vt/vtgate/scatter_conn.go b/go/vt/vtgate/scatter_conn.go
index 8b571f7b67d..697348c3dd5 100644
--- a/go/vt/vtgate/scatter_conn.go
+++ b/go/vt/vtgate/scatter_conn.go
@@ -72,24 +72,41 @@ type shardActionFunc func(rs *srvtopo.ResolvedShard, i int) error
 // the results and errors for the caller.
 type shardActionTransactionFunc func(rs *srvtopo.ResolvedShard, i int, shardActionInfo *shardActionInfo) (*shardActionInfo, error)
 
+var (
+	vttabletTimings = stats.NewMultiTimings(
+		"VttabletCall",
+		"Scatter connection timings",
+		[]string{"Operation", "Keyspace", "ShardName", "DbType"})
+	tabletCallErrorCount = stats.NewCountersWithMultiLabels(
+		"VttabletCallErrorCount",
+		"Error count from tablet calls in scatter conns",
+		[]string{"Operation", "Keyspace", "ShardName", "DbType"})
+)
+
 // NewScatterConn creates a new ScatterConn.
 func NewScatterConn(statsName string, txConn *TxConn, gw *TabletGateway) *ScatterConn {
 	// this only works with TabletGateway
-	tabletCallErrorCountStatsName := ""
-	if statsName != "" {
-		tabletCallErrorCountStatsName = statsName + "ErrorCount"
-	}
-	return &ScatterConn{
-		timings: stats.NewMultiTimings(
-			statsName,
-			"Scatter connection timings",
-			[]string{"Operation", "Keyspace", "ShardName", "DbType"}),
-		tabletCallErrorCount: stats.NewCountersWithMultiLabels(
-			tabletCallErrorCountStatsName,
-			"Error count from tablet calls in scatter conns",
-			[]string{"Operation", "Keyspace", "ShardName", "DbType"}),
-		txConn:  txConn,
-		gateway: gw,
+	if statsName == "" {
+		return &ScatterConn{
+			timings: stats.NewMultiTimings(
+				statsName,
+				"Scatter connection timings",
+				[]string{"Operation", "Keyspace", "ShardName", "DbType"}),
+			tabletCallErrorCount: stats.NewCountersWithMultiLabels(
+				"",
+				"Error count from tablet calls in scatter conns",
+				[]string{"Operation", "Keyspace", "ShardName", "DbType"}),
+			txConn:  txConn,
+			gateway: gw,
+		}
+	} else {
+
+		return &ScatterConn{
+			timings:              vttabletTimings,
+			tabletCallErrorCount: tabletCallErrorCount,
+			txConn:               txConn,
+			gateway:              gw,
+		}
 	}
 }
 
diff --git a/go/vt/vtgate/vtgate.go b/go/vt/vtgate/vtgate.go
index 7d28c0e9697..a38393ef8fb 100644
--- a/go/vt/vtgate/vtgate.go
+++ b/go/vt/vtgate/vtgate.go
@@ -216,6 +216,23 @@ var (
 		[]string{"Operation", "Keyspace", "DbType"})
 )
 
+func ClearMetrics() {
+	vschemaCounters.ResetAll()
+	errorCounts.ResetAll()
+	warnings.ResetAll()
+	vstreamSkewDelayCount.Reset()
+	vindexUnknownParams.Reset()
+	timings.Reset()
+	rowsReturned.ResetAll()
+	rowsAffected.ResetAll()
+	queriesProcessed.ResetAll()
+	queriesRouted.ResetAll()
+	queriesProcessedByTable.ResetAll()
+	queriesRoutedByTable.ResetAll()
+	vttabletTimings.Reset()
+	tabletCallErrorCount.ResetAll()
+}
+
 // VTGate is the rpc interface to vtgate. Only one instance
 // can be created. It implements vtgateservice.VTGateService
 // VTGate exposes multiple generations of interfaces.