schedulers,test: avoid some test branches not being reached and remov…

…e schedulePeerPr (#8087)

close #8073

Signed-off-by: lhy1024 <admin@liudos.us>

Co-authored-by: Hu# <jinhao.hu@pingcap.com>

pkg/schedule/schedulers/grant_hot_region.go

@@ -258,13 +258,13 @@ func newGrantHotRegionHandler(config *grantHotRegionSchedulerConfig) http.Handle
 
 func (s *grantHotRegionScheduler) Schedule(cluster sche.SchedulerCluster, _ bool) ([]*operator.Operator, []plan.Plan) {
 	grantHotRegionCounter.Inc()
-	rw := s.randomRWType()
-	s.prepareForBalance(rw, cluster)
-	return s.dispatch(rw, cluster), nil
+	typ := s.randomType()
+	s.prepareForBalance(typ, cluster)
+	return s.dispatch(typ, cluster), nil
 }
 
-func (s *grantHotRegionScheduler) dispatch(typ utils.RWType, cluster sche.SchedulerCluster) []*operator.Operator {
-	stLoadInfos := s.stLoadInfos[buildResourceType(typ, constant.RegionKind)]
+func (s *grantHotRegionScheduler) dispatch(typ resourceType, cluster sche.SchedulerCluster) []*operator.Operator {
+	stLoadInfos := s.stLoadInfos[typ]
 	infos := make([]*statistics.StoreLoadDetail, len(stLoadInfos))
 	index := 0
 	for _, info := range stLoadInfos {

pkg/schedule/schedulers/hot_region.go

@@ -47,25 +47,26 @@ const (
 	// HotRegionName is balance hot region scheduler name.
 	HotRegionName = "balance-hot-region-scheduler"
 	// HotRegionType is balance hot region scheduler type.
-	HotRegionType          = "hot-region"
-	splitHotReadBuckets    = "split-hot-read-region"
-	splitHotWriteBuckets   = "split-hot-write-region"
-	splitProgressiveRank   = int64(-5)
-	minHotScheduleInterval = time.Second
-	maxHotScheduleInterval = 20 * time.Second
+	HotRegionType           = "hot-region"
+	splitHotReadBuckets     = "split-hot-read-region"
+	splitHotWriteBuckets    = "split-hot-write-region"
+	splitProgressiveRank    = int64(-5)
+	minHotScheduleInterval  = time.Second
+	maxHotScheduleInterval  = 20 * time.Second
+	defaultPendingAmpFactor = 2.0
+	defaultStddevThreshold  = 0.1
+	defaultTopnPosition     = 10
 )
 
 var (
-	// schedulePeerPr the probability of schedule the hot peer.
-	schedulePeerPr = 0.66
 	// pendingAmpFactor will amplify the impact of pending influence, making scheduling slower or even serial when two stores are close together
-	pendingAmpFactor = 2.0
+	pendingAmpFactor = defaultPendingAmpFactor
 	// If the distribution of a dimension is below the corresponding stddev threshold, then scheduling will no longer be based on this dimension,
 	// as it implies that this dimension is sufficiently uniform.
-	stddevThreshold = 0.1
+	stddevThreshold = defaultStddevThreshold
 	// topnPosition is the position of the topn peer in the hot peer list.
 	// We use it to judge whether to schedule the hot peer in some cases.
-	topnPosition = 10
+	topnPosition = defaultTopnPosition
 	// statisticsInterval is the interval to update statistics information.
 	statisticsInterval = time.Second
 )
@@ -120,8 +121,9 @@ type baseHotScheduler struct {
 	// regionPendings stores regionID -> pendingInfluence,
 	// this records regionID which have pending Operator by operation type. During filterHotPeers, the hot peers won't
 	// be selected if its owner region is tracked in this attribute.
-	regionPendings  map[uint64]*pendingInfluence
-	types           []utils.RWType
+	regionPendings map[uint64]*pendingInfluence
+	// types is the resource types that the scheduler considers.
+	types           []resourceType
 	r               *rand.Rand
 	updateReadTime  time.Time
 	updateWriteTime time.Time
@@ -131,26 +133,26 @@ func newBaseHotScheduler(opController *operator.Controller, sampleDuration time.
 	base := NewBaseScheduler(opController)
 	ret := &baseHotScheduler{
 		BaseScheduler:  base,
-		types:          []utils.RWType{utils.Write, utils.Read},
 		regionPendings: make(map[uint64]*pendingInfluence),
 		stHistoryLoads: statistics.NewStoreHistoryLoads(utils.DimLen, sampleDuration, sampleInterval),
 		r:              rand.New(rand.NewSource(time.Now().UnixNano())),
 	}
 	for ty := resourceType(0); ty < resourceTypeLen; ty++ {
+		ret.types = append(ret.types, ty)
 		ret.stLoadInfos[ty] = map[uint64]*statistics.StoreLoadDetail{}
 	}
 	return ret
 }
 
 // prepareForBalance calculate the summary of pending Influence for each store and prepare the load detail for
 // each store, only update read or write load detail
-func (h *baseHotScheduler) prepareForBalance(rw utils.RWType, cluster sche.SchedulerCluster) {
+func (h *baseHotScheduler) prepareForBalance(typ resourceType, cluster sche.SchedulerCluster) {
 	storeInfos := statistics.SummaryStoreInfos(cluster.GetStores())
 	h.summaryPendingInfluence(storeInfos)
 	storesLoads := cluster.GetStoresLoads()
 	isTraceRegionFlow := cluster.GetSchedulerConfig().IsTraceRegionFlow()
 
-	prepare := func(regionStats map[uint64][]*statistics.HotPeerStat, resource constant.ResourceKind) {
+	prepare := func(regionStats map[uint64][]*statistics.HotPeerStat, rw utils.RWType, resource constant.ResourceKind) {
 		ty := buildResourceType(rw, resource)
 		h.stLoadInfos[ty] = statistics.SummaryStoresLoad(
 			storeInfos,
@@ -160,23 +162,25 @@ func (h *baseHotScheduler) prepareForBalance(rw utils.RWType, cluster sche.Sched
 			isTraceRegionFlow,
 			rw, resource)
 	}
-	switch rw {
-	case utils.Read:
+	switch typ {
+	case readLeader, readPeer:
 		// update read statistics
 		if time.Since(h.updateReadTime) >= statisticsInterval {
 			regionRead := cluster.RegionReadStats()
-			prepare(regionRead, constant.LeaderKind)
-			prepare(regionRead, constant.RegionKind)
+			prepare(regionRead, utils.Read, constant.LeaderKind)
+			prepare(regionRead, utils.Read, constant.RegionKind)
 			h.updateReadTime = time.Now()
 		}
-	case utils.Write:
+	case writeLeader, writePeer:
 		// update write statistics
 		if time.Since(h.updateWriteTime) >= statisticsInterval {
 			regionWrite := cluster.RegionWriteStats()
-			prepare(regionWrite, constant.LeaderKind)
-			prepare(regionWrite, constant.RegionKind)
+			prepare(regionWrite, utils.Write, constant.LeaderKind)
+			prepare(regionWrite, utils.Write, constant.RegionKind)
 			h.updateWriteTime = time.Now()
 		}
+	default:
+		log.Error("invalid resource type", zap.String("type", typ.String()))
 	}
 }
 
@@ -223,7 +227,7 @@ func setHotPendingInfluenceMetrics(storeLabel, rwTy, dim string, load float64) {
 	HotPendingSum.WithLabelValues(storeLabel, rwTy, dim).Set(load)
 }
 
-func (h *baseHotScheduler) randomRWType() utils.RWType {
+func (h *baseHotScheduler) randomType() resourceType {
 	return h.types[h.r.Int()%len(h.types)]
 }
 
@@ -324,24 +328,32 @@ func (h *hotScheduler) IsScheduleAllowed(cluster sche.SchedulerCluster) bool {
 
 func (h *hotScheduler) Schedule(cluster sche.SchedulerCluster, _ bool) ([]*operator.Operator, []plan.Plan) {
 	hotSchedulerCounter.Inc()
-	rw := h.randomRWType()
-	return h.dispatch(rw, cluster), nil
+	typ := h.randomType()
+	return h.dispatch(typ, cluster), nil
 }
 
-func (h *hotScheduler) dispatch(typ utils.RWType, cluster sche.SchedulerCluster) []*operator.Operator {
+func (h *hotScheduler) dispatch(typ resourceType, cluster sche.SchedulerCluster) []*operator.Operator {
 	h.Lock()
 	defer h.Unlock()
 	h.updateHistoryLoadConfig(h.conf.GetHistorySampleDuration(), h.conf.GetHistorySampleInterval())
 	h.prepareForBalance(typ, cluster)
-	// it can not move earlier to support to use api and metrics.
-	if h.conf.IsForbidRWType(typ) {
-		return nil
-	}
+	// IsForbidRWType can not be move earlier to support to use api and metrics.
 	switch typ {
-	case utils.Read:
+	case readLeader, readPeer:
+		if h.conf.IsForbidRWType(utils.Read) {
+			return nil
+		}
 		return h.balanceHotReadRegions(cluster)
-	case utils.Write:
-		return h.balanceHotWriteRegions(cluster)
+	case writePeer:
+		if h.conf.IsForbidRWType(utils.Write) {
+			return nil
+		}
+		return h.balanceHotWritePeers(cluster)
+	case writeLeader:
+		if h.conf.IsForbidRWType(utils.Write) {
+			return nil
+		}
+		return h.balanceHotWriteLeaders(cluster)
 	}
 	return nil
 }
@@ -406,19 +418,16 @@ func (h *hotScheduler) balanceHotReadRegions(cluster sche.SchedulerCluster) []*o
 	return nil
 }
 
-func (h *hotScheduler) balanceHotWriteRegions(cluster sche.SchedulerCluster) []*operator.Operator {
-	// prefer to balance by peer
-	s := h.r.Intn(100)
-	switch {
-	case s < int(schedulePeerPr*100):
-		peerSolver := newBalanceSolver(h, cluster, utils.Write, movePeer)
-		ops := peerSolver.solve()
-		if len(ops) > 0 && peerSolver.tryAddPendingInfluence() {
-			return ops
-		}
-	default:
+func (h *hotScheduler) balanceHotWritePeers(cluster sche.SchedulerCluster) []*operator.Operator {
+	peerSolver := newBalanceSolver(h, cluster, utils.Write, movePeer)
+	ops := peerSolver.solve()
+	if len(ops) > 0 && peerSolver.tryAddPendingInfluence() {
+		return ops
 	}
+	return nil
+}
 
+func (h *hotScheduler) balanceHotWriteLeaders(cluster sche.SchedulerCluster) []*operator.Operator {
 	leaderSolver := newBalanceSolver(h, cluster, utils.Write, transferLeader)
 	ops := leaderSolver.solve()
 	if len(ops) > 0 && leaderSolver.tryAddPendingInfluence() {