scheduler: make SrcToleranceRatio and DstToleranceRatio enable fo…

…r `stddev` (#5546) ref #5545 Signed-off-by: lhy1024 <[email protected]> Co-authored-by: Ti Chi Robot <[email protected]>
tikv · Sep 23, 2022 · 85ace3d · 85ace3d
1 parent 02f5639
commit 85ace3d
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Showing 4 changed files with 26 additions and 12 deletions.
diff --git a/server/schedulers/hot_region.go b/server/schedulers/hot_region.go
@@ -545,6 +545,9 @@ func (bs *balanceSolver) isValid() bool {
 }
 
 func (bs *balanceSolver) filterUniformStoreV1() (string, bool) {
+	if !bs.enableExpectation() {
+		return "", false
+	}
 	// Because region is available for src and dst, so stddev is the same for both, only need to calcurate one.
 	isUniformFirstPriority, isUniformSecondPriority := bs.isUniformFirstPriority(bs.cur.srcStore), bs.isUniformSecondPriority(bs.cur.srcStore)
 	if isUniformFirstPriority && isUniformSecondPriority {
@@ -973,6 +976,10 @@ func (bs *balanceSolver) checkByPriorityAndToleranceFirstOnly(loads []float64, f
 	return f(bs.firstPriority)
 }
 
+func (bs *balanceSolver) enableExpectation() bool {
+	return bs.sche.conf.GetDstToleranceRatio() > 0 && bs.sche.conf.GetSrcToleranceRatio() > 0
+}
+
 func (bs *balanceSolver) isUniformFirstPriority(store *statistics.StoreLoadDetail) bool {
 	// first priority should be more uniform than second priority
 	return store.IsUniform(bs.firstPriority, stddevThreshold*0.5)

diff --git a/server/schedulers/hot_region_config.go b/server/schedulers/hot_region_config.go
@@ -118,20 +118,24 @@ type hotRegionSchedulerConfig struct {
 
 	// rank step ratio decide the step when calculate rank
 	// step = max current * rank step ratio
-	ByteRateRankStepRatio  float64  `json:"byte-rate-rank-step-ratio"`
-	KeyRateRankStepRatio   float64  `json:"key-rate-rank-step-ratio"`
-	QueryRateRankStepRatio float64  `json:"query-rate-rank-step-ratio"`
-	CountRankStepRatio     float64  `json:"count-rank-step-ratio"`
-	GreatDecRatio          float64  `json:"great-dec-ratio"`
-	MinorDecRatio          float64  `json:"minor-dec-ratio"` // only for v1
-	SrcToleranceRatio      float64  `json:"src-tolerance-ratio"`
-	DstToleranceRatio      float64  `json:"dst-tolerance-ratio"`
-	ReadPriorities         []string `json:"read-priorities"`
+	ByteRateRankStepRatio  float64 `json:"byte-rate-rank-step-ratio"`
+	KeyRateRankStepRatio   float64 `json:"key-rate-rank-step-ratio"`
+	QueryRateRankStepRatio float64 `json:"query-rate-rank-step-ratio"`
+	CountRankStepRatio     float64 `json:"count-rank-step-ratio"`
+	GreatDecRatio          float64 `json:"great-dec-ratio"`
+	MinorDecRatio          float64 `json:"minor-dec-ratio"` // only for v1
+
+	// If SrcToleranceRatio and DstToleranceRatio are zero,
+	// it means hot region scheduler will not consider about expectation and variance.
+	SrcToleranceRatio float64 `json:"src-tolerance-ratio"`
+	DstToleranceRatio float64 `json:"dst-tolerance-ratio"`
 
 	// For first priority of write leader, it is better to consider key rate or query rather than byte
 	WriteLeaderPriorities []string `json:"write-leader-priorities"`
 	WritePeerPriorities   []string `json:"write-peer-priorities"`
-	StrictPickingStore    bool     `json:"strict-picking-store,string"` // only for v1
+	ReadPriorities        []string `json:"read-priorities"`
+
+	StrictPickingStore bool `json:"strict-picking-store,string"` // only for v1
 
 	// Separately control whether to start hotspot scheduling for TiFlash
 	EnableForTiFlash bool `json:"enable-for-tiflash,string"`

diff --git a/server/schedulers/hot_region_test.go b/server/schedulers/hot_region_test.go
@@ -1978,8 +1978,8 @@ func TestHotScheduleWithStddev(t *testing.T) {
 	opt := config.NewTestOptions()
 	hb, err := schedule.CreateScheduler(statistics.Write.String(), schedule.NewOperatorController(ctx, nil, nil), storage.NewStorageWithMemoryBackend(), nil)
 	re.NoError(err)
-	hb.(*hotScheduler).conf.SetDstToleranceRatio(0.0)
-	hb.(*hotScheduler).conf.SetSrcToleranceRatio(0.0)
+	hb.(*hotScheduler).conf.SetDstToleranceRatio(1.0)
+	hb.(*hotScheduler).conf.SetSrcToleranceRatio(1.0)
 	tc := mockcluster.NewCluster(ctx, opt)
 	tc.SetClusterVersion(versioninfo.MinSupportedVersion(versioninfo.Version4_0))
 	tc.SetHotRegionCacheHitsThreshold(0)

diff --git a/server/schedulers/hot_region_v2.go b/server/schedulers/hot_region_v2.go
@@ -92,6 +92,9 @@ func (bs *balanceSolver) pickCheckPolicyV2() {
 }
 
 func (bs *balanceSolver) filterUniformStoreV2() (string, bool) {
+	if !bs.enableExpectation() {
+		return "", false
+	}
 	// Because region is available for src and dst, so stddev is the same for both, only need to calcurate one.
 	isUniformFirstPriority, isUniformSecondPriority := bs.isUniformFirstPriority(bs.cur.srcStore), bs.isUniformSecondPriority(bs.cur.srcStore)
 	if isUniformFirstPriority && isUniformSecondPriority {