diff --git a/pkg/cluster/cluster.go b/pkg/cluster/cluster.go
index 3edefbcaefd..8bd2616f41f 100644
--- a/pkg/cluster/cluster.go
+++ b/pkg/cluster/cluster.go
@@ -59,7 +59,11 @@ func HandleOverlaps(c Cluster, overlaps []*core.RegionInfo) {
 func Collect(c Cluster, region *core.RegionInfo, hasRegionStats bool) {
 	if hasRegionStats {
 		// get region again from root tree. make sure the observed region is the latest.
-		region = c.GetBasicCluster().GetRegion(region.GetID())
+		bc := c.GetBasicCluster()
+		if bc == nil {
+			return
+		}
+		region = bc.GetRegion(region.GetID())
 		if region == nil {
 			return
 		}
diff --git a/pkg/mcs/scheduling/server/cluster.go b/pkg/mcs/scheduling/server/cluster.go
index 76a9d770ce7..5e7a7a6f6a9 100644
--- a/pkg/mcs/scheduling/server/cluster.go
+++ b/pkg/mcs/scheduling/server/cluster.go
@@ -63,6 +63,9 @@ const (
 	regionLabelGCInterval = time.Hour
 	requestTimeout        = 3 * time.Second
 	collectWaitTime       = time.Minute
+
+	// heartbeat relative const
+	hbAsyncRunner = "heartbeat-async-task-runner"
 )
 
 var syncRunner = ratelimit.NewSyncRunner()
@@ -90,7 +93,7 @@ func NewCluster(parentCtx context.Context, persistConfig *config.PersistConfig,
 		clusterID:         clusterID,
 		checkMembershipCh: checkMembershipCh,
 
-		taskRunner:           ratelimit.NewAsyncRunner("heartbeat-async-task-runner", time.Minute),
+		taskRunner:           ratelimit.NewAsyncRunner(hbAsyncRunner, time.Minute),
 		hbConcurrencyLimiter: ratelimit.NewConcurrencyLimiter(uint64(runtime.NumCPU() * 2)),
 	}
 	c.coordinator = schedule.NewCoordinator(ctx, c, hbStreams)
diff --git a/pkg/statistics/region_collection.go b/pkg/statistics/region_collection.go
index 52655b093a2..488763142e1 100644
--- a/pkg/statistics/region_collection.go
+++ b/pkg/statistics/region_collection.go
@@ -157,6 +157,18 @@ func (r *RegionStatistics) RegionStatsNeedUpdate(region *core.RegionInfo) bool {
 		region.IsOversized(int64(r.conf.GetRegionMaxSize()), int64(r.conf.GetRegionMaxKeys())) {
 		return true
 	}
+	// expected to be zero for below type
+	if r.IsRegionStatsType(regionID, PendingPeer) && len(region.GetPendingPeers()) == 0 {
+		return true
+	}
+	if r.IsRegionStatsType(regionID, DownPeer) && len(region.GetDownPeers()) == 0 {
+		return true
+	}
+	if r.IsRegionStatsType(regionID, LearnerPeer) && len(region.GetLearners()) == 0 {
+		return true
+	}
+
+	// merge
 	return r.IsRegionStatsType(regionID, UndersizedRegion) !=
 		region.NeedMerge(int64(r.conf.GetMaxMergeRegionSize()), int64(r.conf.GetMaxMergeRegionKeys()))
 }
diff --git a/server/cluster/cluster.go b/server/cluster/cluster.go
index 95507d8c4aa..d9bf15e4d34 100644
--- a/server/cluster/cluster.go
+++ b/server/cluster/cluster.go
@@ -106,6 +106,9 @@ const (
 	// minSnapshotDurationSec is the minimum duration that a store can tolerate.
 	// It should enlarge the limiter if the snapshot's duration is less than this value.
 	minSnapshotDurationSec = 5
+
+	// heartbeat relative const
+	hbAsyncRunner = "heartbeat-async-task-runner"
 )
 
 // Server is the interface for cluster.
@@ -195,7 +198,7 @@ func NewRaftCluster(ctx context.Context, clusterID uint64, basicCluster *core.Ba
 		etcdClient:           etcdClient,
 		core:                 basicCluster,
 		storage:              storage,
-		taskRunner:           ratelimit.NewAsyncRunner("heartbeat-async-task-runner", time.Minute),
+		taskRunner:           ratelimit.NewAsyncRunner(hbAsyncRunner, time.Minute),
 		hbConcurrencyLimiter: ratelimit.NewConcurrencyLimiter(uint64(runtime.NumCPU() * 2)),
 	}
 }