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Signed-off-by: yisaer <disxiaofei@163.com>

server/statistics/hot_cache.go

@@ -46,7 +46,7 @@ func NewHotCache(ctx context.Context) *HotCache {
 	return w
 }
 
-// ExpiredItems returns the items which are already expired.
+// ExpiredItems returns the items which are already expired.:
 func (w *HotCache) ExpiredItems(region *core.RegionInfo) (expiredItems []*HotPeerStat) {
 	expiredItems = append(expiredItems, w.writeFlow.ExpiredItems(region)...)
 	expiredItems = append(expiredItems, w.readFlow.ExpiredItems(region)...)

server/statistics/hot_peer_cache.go

@@ -33,7 +33,6 @@ const (
 	// WriteReportInterval indicates the interval between write interval
 	WriteReportInterval = RegionHeartBeatReportInterval
 	// ReadReportInterval indicates the interval between read stats report
-	// TODO: use StoreHeartBeatReportInterval in future
 	ReadReportInterval = StoreHeartBeatReportInterval
 
 	rollingWindowsSize = 5
@@ -208,7 +207,7 @@ func (f *hotPeerCache) CheckPeerFlow(peer *core.PeerInfo, region *core.RegionInf
 		loads[i] = deltaLoads[i] / float64(interval)
 	}
 	justTransferLeader := f.justTransferLeader(region)
-	// transfer read leader or remove write peer
+	// remove peer
 	isExpired := f.isPeerExpired(peer, region)
 	oldItem := f.getOldHotPeerStat(region.GetID(), storeID)
 	if isExpired && oldItem != nil {
@@ -284,14 +283,7 @@ func (f *hotPeerCache) getOldHotPeerStat(regionID, storeID uint64) *HotPeerStat
 
 func (f *hotPeerCache) isPeerExpired(peer *core.PeerInfo, region *core.RegionInfo) bool {
 	storeID := peer.GetStoreID()
-	switch f.kind {
-	case WriteFlow:
-		return region.GetStorePeer(storeID) == nil
-	//TODO: make readFlow isPeerExpired condition as same as the writeFlow
-	case ReadFlow:
-		return region.GetLeader().GetStoreId() != storeID
-	}
-	return false
+	return region.GetStorePeer(storeID) == nil
 }
 
 func (f *hotPeerCache) calcHotThresholds(storeID uint64) []float64 {
@@ -444,6 +436,8 @@ func (f *hotPeerCache) updateHotPeerStat(newItem, oldItem *HotPeerStat, deltaLoa
 		newItem.lastTransferLeaderTime = time.Now()
 		// skip the first heartbeat flow statistic after transfer leader, because its statistics are calculated by the last leader in this store and are inaccurate
 		// maintain anticount and hotdegree to avoid store threshold and hot peer are unstable.
+		// For write stat, as the stat is send by region heartbeat, the first heartbeat will be skipped.
+		// For read stat, as the stat is send by store heartbeat, the first heartbeat won't be skipped.
 		if newItem.Kind == WriteFlow {
 			newItem.HotDegree = oldItem.HotDegree
 			newItem.AntiCount = oldItem.AntiCount

server/statistics/hot_peer_cache_test.go

@@ -67,19 +67,19 @@ const (
 )
 
 type testCacheCase struct {
-	kind     FlowKind
-	operator operator
-	expect   int
+	kind       FlowKind
+	operator   operator
+	expect     int
+	needDelete bool
 }
 
 func (t *testHotPeerCache) TestCache(c *C) {
 	tests := []*testCacheCase{
-		{ReadFlow, transferLeader, 2},
-		{ReadFlow, movePeer, 1},
-		{ReadFlow, addReplica, 1},
-		{WriteFlow, transferLeader, 3},
-		{WriteFlow, movePeer, 4},
-		{WriteFlow, addReplica, 4},
+		{ReadFlow, movePeer, 1, false},
+		{ReadFlow, addReplica, 1, true},
+		{WriteFlow, transferLeader, 3, true},
+		{WriteFlow, movePeer, 4, true},
+		{WriteFlow, addReplica, 4, true},
 	}
 	for _, t := range tests {
 		testCache(c, t)
@@ -100,7 +100,7 @@ func testCache(c *C, t *testCacheCase) {
 	res := checkAndUpdate(c, cache, region, t.expect)
 	checkHit(c, cache, region, t.kind, true) // hit cache
 	if t.expect != defaultSize[t.kind] {
-		checkNeedDelete(c, res, srcStore)
+		checkNeedDelete(c, res, srcStore, t.needDelete)
 	}
 }
 
@@ -127,10 +127,10 @@ func checkHit(c *C, cache *hotPeerCache, region *core.RegionInfo, kind FlowKind,
 	}
 }
 
-func checkNeedDelete(c *C, ret []*HotPeerStat, storeID uint64) {
+func checkNeedDelete(c *C, ret []*HotPeerStat, storeID uint64, needDelete bool) {
 	for _, item := range ret {
 		if item.StoreID == storeID {
-			c.Assert(item.needDelete, IsTrue)
+			c.Assert(item.needDelete, Equals, needDelete)
 			return
 		}
 	}