Throttler: refactor stats variables (#15574)

Signed-off-by: Shlomi Noach <[email protected]>

go/vt/vttablet/tabletserver/throttle/check.go

@@ -58,6 +58,11 @@ const (
 	selfCheckInterval = 250 * time.Millisecond
 )
 
+var (
+	statsThrottlerCheckAnyTotal = stats.NewCounter("ThrottlerCheckAnyTotal", "total number of checks")
+	statsThrottlerCheckAnyError = stats.GetOrNewCounter("ThrottlerCheckAnyError", "total number of failed checks")
+)
+
 // CheckFlags provide hints for a check
 type CheckFlags struct {
 	ReadCheck             bool
@@ -151,11 +156,11 @@ func (check *ThrottlerCheck) Check(ctx context.Context, appName string, storeTyp
 	check.throttler.markRecentApp(appName, remoteAddr)
 	if !throttlerapp.VitessName.Equals(appName) {
 		go func(statusCode int) {
-			stats.GetOrNewCounter("ThrottlerCheckAnyTotal", "total number of checks").Add(1)
+			statsThrottlerCheckAnyTotal.Add(1)
 			stats.GetOrNewCounter(fmt.Sprintf("ThrottlerCheckAny%s%sTotal", textutil.SingleWordCamel(storeType), textutil.SingleWordCamel(storeName)), "").Add(1)
 
 			if statusCode != http.StatusOK {
-				stats.GetOrNewCounter("ThrottlerCheckAnyError", "total number of failed checks").Add(1)
+				statsThrottlerCheckAnyError.Add(1)
 				stats.GetOrNewCounter(fmt.Sprintf("ThrottlerCheckAny%s%sError", textutil.SingleWordCamel(storeType), textutil.SingleWordCamel(storeName)), "").Add(1)
 			}
 		}(checkResult.StatusCode)

go/vt/vttablet/tabletserver/throttle/throttler.go

@@ -111,6 +111,12 @@ var (
 	throttleTabletTypes         = "replica"
 )
 
+var (
+	statsThrottlerHeartbeatRequests    = stats.NewCounter("ThrottlerHeartbeatRequests", "heartbeat requests")
+	statsThrottlerRecentlyChecked      = stats.NewCounter("ThrottlerRecentlyChecked", "recently checked")
+	statsThrottlerProbeRecentlyChecked = stats.NewCounter("ThrottlerProbeRecentlyChecked", "probe recently checked")
+)
+
 func init() {
 	servenv.OnParseFor("vtcombo", registerThrottlerFlags)
 	servenv.OnParseFor("vttablet", registerThrottlerFlags)
@@ -577,7 +583,7 @@ func (throttler *Throttler) requestHeartbeats() {
 		return
 	}
 	go throttler.heartbeatWriter.RequestHeartbeats()
-	go stats.GetOrNewCounter("ThrottlerHeartbeatRequests", "heartbeat requests").Add(1)
+	statsThrottlerHeartbeatRequests.Add(1)
 }
 
 // stimulatePrimaryThrottler sends a check request to the primary tablet in the shard, to stimulate
@@ -852,7 +858,7 @@ func (throttler *Throttler) generateTabletProbeFunction(ctx context.Context, clu
 			// We have just probed a tablet, and it reported back that someone just recently "check"ed it.
 			// We therefore renew the heartbeats lease.
 			throttler.requestHeartbeats()
-			go stats.GetOrNewCounter("ThrottlerProbeRecentlyChecked", "probe recently checked").Add(1)
+			statsThrottlerProbeRecentlyChecked.Add(1)
 		}
 		return mySQLThrottleMetric
 	}
@@ -1256,7 +1262,7 @@ func (throttler *Throttler) checkStore(ctx context.Context, appName string, stor
 		// We mark the fact that someone just made a check. If this is a REPLICA or RDONLY tables, this will be reported back
 		// to the PRIMARY so that it knows it must renew the heartbeat lease.
 		checkResult.RecentlyChecked = true
-		go stats.GetOrNewCounter("ThrottlerRecentlyChecked", "recently checked").Add(1)
+		statsThrottlerRecentlyChecked.Add(1)
 	}
 
 	return checkResult