From 84138e4b876908274f68cedbb4c5e4c57472ee34 Mon Sep 17 00:00:00 2001
From: okJiang <819421878@qq.com>
Date: Thu, 22 Aug 2024 15:27:13 +0800
Subject: [PATCH] heartbeat: reduce unnecessary `RunTask` (#8559)

ref tikv/pd#7897

Signed-off-by: okJiang <819421878@qq.com>

Co-authored-by: ti-chi-bot[bot] <108142056+ti-chi-bot[bot]@users.noreply.github.com>
---
 pkg/cluster/cluster.go               | 32 +++++++++++++---------------
 pkg/mcs/scheduling/server/cluster.go | 21 ++++++++++--------
 server/cluster/cluster.go            | 26 +++++++++++-----------
 3 files changed, 41 insertions(+), 38 deletions(-)

diff --git a/pkg/cluster/cluster.go b/pkg/cluster/cluster.go
index ddba8f89fb6..b1abe4677df 100644
--- a/pkg/cluster/cluster.go
+++ b/pkg/cluster/cluster.go
@@ -74,22 +74,20 @@ func HandleOverlaps(ctx context.Context, c Cluster, overlaps []*core.RegionInfo)
 }
 
 // Collect collects the cluster information.
-func Collect(ctx context.Context, c Cluster, region *core.RegionInfo, hasRegionStats bool) {
-	if hasRegionStats {
-		// get region again from root tree. make sure the observed region is the latest.
-		bc := c.GetBasicCluster()
-		if bc == nil {
-			return
-		}
-		region = bc.GetRegion(region.GetID())
-		if region == nil {
-			return
-		}
-		select {
-		case <-ctx.Done():
-			return
-		default:
-		}
-		c.GetRegionStats().Observe(region, c.GetBasicCluster().GetRegionStores(region))
+func Collect(ctx context.Context, c Cluster, region *core.RegionInfo) {
+	// get region again from root tree. make sure the observed region is the latest.
+	bc := c.GetBasicCluster()
+	if bc == nil {
+		return
+	}
+	region = bc.GetRegion(region.GetID())
+	if region == nil {
+		return
+	}
+	select {
+	case <-ctx.Done():
+		return
+	default:
 	}
+	c.GetRegionStats().Observe(region, c.GetBasicCluster().GetRegionStores(region))
 }
diff --git a/pkg/mcs/scheduling/server/cluster.go b/pkg/mcs/scheduling/server/cluster.go
index 31120ae6082..0dcb26a1a1f 100644
--- a/pkg/mcs/scheduling/server/cluster.go
+++ b/pkg/mcs/scheduling/server/cluster.go
@@ -631,7 +631,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 				regionID,
 				ratelimit.ObserveRegionStatsAsync,
 				func(ctx context.Context) {
-					cluster.Collect(ctx, c, region, hasRegionStats)
+					cluster.Collect(ctx, c, region)
 				},
 			)
 		}
@@ -679,14 +679,17 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 		)
 	}
 	tracer.OnSaveCacheFinished()
-	// handle region stats
-	ctx.TaskRunner.RunTask(
-		regionID,
-		ratelimit.CollectRegionStatsAsync,
-		func(ctx context.Context) {
-			cluster.Collect(ctx, c, region, hasRegionStats)
-		},
-	)
+	if hasRegionStats {
+		// handle region stats
+		ctx.TaskRunner.RunTask(
+			regionID,
+			ratelimit.CollectRegionStatsAsync,
+			func(ctx context.Context) {
+				cluster.Collect(ctx, c, region)
+			},
+		)
+	}
+
 	tracer.OnCollectRegionStatsFinished()
 	return nil
 }
diff --git a/server/cluster/cluster.go b/server/cluster/cluster.go
index 9e12b158f42..9e85a0f1d84 100644
--- a/server/cluster/cluster.go
+++ b/server/cluster/cluster.go
@@ -1062,7 +1062,7 @@ func (c *RaftCluster) processRegionHeartbeat(ctx *core.MetaProcessContext, regio
 				regionID,
 				ratelimit.ObserveRegionStatsAsync,
 				func(ctx context.Context) {
-					cluster.Collect(ctx, c, region, hasRegionStats)
+					cluster.Collect(ctx, c, region)
 				},
 			)
 		}
@@ -1119,17 +1119,19 @@ func (c *RaftCluster) processRegionHeartbeat(ctx *core.MetaProcessContext, regio
 	}
 
 	tracer.OnSaveCacheFinished()
-	// handle region stats
-	ctx.MiscRunner.RunTask(
-		regionID,
-		ratelimit.CollectRegionStatsAsync,
-		func(ctx context.Context) {
-			// TODO: Due to the accuracy requirements of the API "/regions/check/xxx",
-			// region stats needs to be collected in API mode.
-			// We need to think of a better way to reduce this part of the cost in the future.
-			cluster.Collect(ctx, c, region, hasRegionStats)
-		},
-	)
+	if hasRegionStats {
+		// handle region stats
+		ctx.MiscRunner.RunTask(
+			regionID,
+			ratelimit.CollectRegionStatsAsync,
+			func(ctx context.Context) {
+				// TODO: Due to the accuracy requirements of the API "/regions/check/xxx",
+				// region stats needs to be collected in API mode.
+				// We need to think of a better way to reduce this part of the cost in the future.
+				cluster.Collect(ctx, c, region)
+			},
+		)
+	}
 
 	tracer.OnCollectRegionStatsFinished()
 	if c.storage != nil {