store: remove stores that have no region before balance

pkg/store/copr/BUILD.bazel

@@ -81,7 +81,7 @@ go_test(
     embed = [":copr"],
     flaky = True,
     race = "on",
-    shard_count = 29,
+    shard_count = 30,
     deps = [
         "//pkg/kv",
         "//pkg/store/driver/backoff",
@@ -91,6 +91,7 @@ go_test(
         "//pkg/util/trxevents",
         "@com_github_pingcap_errors//:errors",
         "@com_github_pingcap_kvproto//pkg/coprocessor",
+        "@com_github_pingcap_kvproto//pkg/metapb",
         "@com_github_pingcap_kvproto//pkg/mpp",
         "@com_github_stathat_consistent//:consistent",
         "@com_github_stretchr_testify//require",

pkg/store/copr/batch_coprocessor.go

@@ -304,7 +304,7 @@ func balanceBatchCopTaskWithContinuity(storeTaskMap map[uint64]*batchCopTask, ca
 //
 // The second balance strategy: Not only consider the region count between TiFlash stores, but also try to make the regions' range continuous(stored in TiFlash closely).
 // If balanceWithContinuity is true, the second balance strategy is enable.
-func balanceBatchCopTask(ctx context.Context, aliveStores []*tikv.Store, originalTasks []*batchCopTask, balanceWithContinuity bool, balanceContinuousRegionCount int64) []*batchCopTask {
+func balanceBatchCopTask(aliveStores []*tikv.Store, originalTasks []*batchCopTask, balanceWithContinuity bool, balanceContinuousRegionCount int64) []*batchCopTask {
 	if len(originalTasks) == 0 {
 		log.Info("Batch cop task balancer got an empty task set.")
 		return originalTasks
@@ -819,12 +819,24 @@ func filterAllStoresAccordingToTiFlashReplicaRead(allStores []uint64, aliveStore
 	return
 }
 
+func getAllUsedTiFlashStores(allTiFlashStores []*tikv.Store, allUsedTiFlashStoresMap map[uint64]struct{}) []*tikv.Store {
+	allUsedTiFlashStores := make([]*tikv.Store, 0, len(allUsedTiFlashStoresMap))
+	for _, store := range allTiFlashStores {
+		_, ok := allUsedTiFlashStoresMap[store.StoreID()]
+		if ok {
+			allUsedTiFlashStores = append(allUsedTiFlashStores, store)
+		}
+	}
+	return allUsedTiFlashStores
+}
+
 // getAliveStoresAndStoreIDs gets alive TiFlash stores and their IDs.
 // If tiflashReplicaReadPolicy is not all_replicas, it will also return the IDs of the alive TiFlash stores in TiDB zone.
-func getAliveStoresAndStoreIDs(ctx context.Context, cache *RegionCache, ttl time.Duration, store *kvStore, tiflashReplicaReadPolicy tiflash.ReplicaRead, tidbZone string) (aliveStores *aliveStoresBundle) {
+func getAliveStoresAndStoreIDs(ctx context.Context, cache *RegionCache, allUsedTiFlashStoresMap map[uint64]struct{}, ttl time.Duration, store *kvStore, tiflashReplicaReadPolicy tiflash.ReplicaRead, tidbZone string) (aliveStores *aliveStoresBundle) {
 	aliveStores = new(aliveStoresBundle)
 	allTiFlashStores := cache.RegionCache.GetTiFlashStores(tikv.LabelFilterNoTiFlashWriteNode)
-	aliveStores.storesInAllZones = filterAliveStores(ctx, allTiFlashStores, ttl, store)
+	allUsedTiFlashStores := getAllUsedTiFlashStores(allTiFlashStores, allUsedTiFlashStoresMap)
+	aliveStores.storesInAllZones = filterAliveStores(ctx, allUsedTiFlashStores, ttl, store)
 
 	if !tiflashReplicaReadPolicy.IsAllReplicas() {
 		aliveStores.storeIDsInTiDBZone = make(map[uint64]struct{}, len(aliveStores.storesInAllZones))
@@ -849,11 +861,28 @@ func getAliveStoresAndStoreIDs(ctx context.Context, cache *RegionCache, ttl time
 // 1. tiflash_replica_read policy
 // 2. whether the store is alive
 // After filtering, it will build the RegionInfo.
-func filterAccessibleStoresAndBuildRegionInfo(cache *RegionCache, bo *Backoffer, task *copTask, rpcCtx *tikv.RPCContext, aliveStores *aliveStoresBundle, isTiDBLabelZoneSet bool, tiflashReplicaReadPolicy tiflash.ReplicaRead, regionInfoNeedsReloadOnSendFail []RegionInfo, regionsInOtherZones []uint64, maxRemoteReadCountAllowed int, tidbZone string) (regionInfo RegionInfo, _ []RegionInfo, _ []uint64, err error) {
+func filterAccessibleStoresAndBuildRegionInfo(
+	cache *RegionCache,
+	allStores []uint64,
+	bo *Backoffer,
+	task *copTask,
+	rpcCtx *tikv.RPCContext,
+	aliveStores *aliveStoresBundle,
+	tiflashReplicaReadPolicy tiflash.ReplicaRead,
+	regionInfoNeedsReloadOnSendFail []RegionInfo,
+	regionsInOtherZones []uint64,
+	maxRemoteReadCountAllowed int,
+	tidbZone string) (regionInfo RegionInfo, _ []RegionInfo, _ []uint64, err error) {
 	needCrossZoneAccess := false
-	allStores, _ := cache.GetAllValidTiFlashStores(task.region, rpcCtx.Store, tikv.LabelFilterNoTiFlashWriteNode)
 	allStores, needCrossZoneAccess = filterAllStoresAccordingToTiFlashReplicaRead(allStores, aliveStores, tiflashReplicaReadPolicy)
-	regionInfo = RegionInfo{Region: task.region, Meta: rpcCtx.Meta, Ranges: task.ranges, AllStores: allStores, PartitionIndex: task.partitionIndex}
+
+	regionInfo = RegionInfo{
+		Region:         task.region,
+		Meta:           rpcCtx.Meta,
+		Ranges:         task.ranges,
+		AllStores:      allStores,
+		PartitionIndex: task.partitionIndex}
+
 	if needCrossZoneAccess {
 		regionsInOtherZones = append(regionsInOtherZones, task.region.GetID())
 		regionInfoNeedsReloadOnSendFail = append(regionInfoNeedsReloadOnSendFail, regionInfo)
@@ -862,7 +891,9 @@ func filterAccessibleStoresAndBuildRegionInfo(cache *RegionCache, bo *Backoffer,
 			for i := 0; i < 3 && i < len(regionsInOtherZones); i++ {
 				regionIDErrMsg += fmt.Sprintf("%d, ", regionsInOtherZones[i])
 			}
-			err = errors.Errorf("no less than %d region(s) can not be accessed by TiFlash in the zone [%s]: %setc", len(regionsInOtherZones), tidbZone, regionIDErrMsg)
+			err = errors.Errorf(
+				"no less than %d region(s) can not be accessed by TiFlash in the zone [%s]: %setc",
+				len(regionsInOtherZones), tidbZone, regionIDErrMsg)
 			// We need to reload the region cache here to avoid the failure throughout the region cache refresh TTL.
 			cache.OnSendFailForBatchRegions(bo, rpcCtx.Store, regionInfoNeedsReloadOnSendFail, true, err)
 			return regionInfo, nil, nil, err
@@ -895,10 +926,7 @@ func buildBatchCopTasksCore(bo *backoff.Backoffer, store *kvStore, rangesForEach
 	if !isTiDBLabelZoneSet {
 		tiflashReplicaReadPolicy = tiflash.AllReplicas
 	}
-	aliveStores = getAliveStoresAndStoreIDs(bo.GetCtx(), cache, ttl, store, tiflashReplicaReadPolicy, tidbZone)
-	if tiflashReplicaReadPolicy.IsClosestReplicas() {
-		maxRemoteReadCountAllowed = len(aliveStores.storeIDsInTiDBZone) * tiflash.MaxRemoteReadCountPerNodeForClosestReplicas
-	}
+
 	for {
 		var tasks []*copTask
 		rangesLen = 0
@@ -919,17 +947,16 @@ func buildBatchCopTasksCore(bo *backoff.Backoffer, store *kvStore, rangesForEach
 			}
 		}
 
-		var batchTasks []*batchCopTask
-		var regionIDsInOtherZones []uint64
-		var regionInfosNeedReloadOnSendFail []RegionInfo
-		storeTaskMap := make(map[string]*batchCopTask)
+		rpcCtxs := make([]*tikv.RPCContext, 0, len(tasks))
+		usedTiFlashStores := make([][]uint64, 0, len(tasks))
+		usedTiFlashStoresMap := make(map[uint64]struct{}, 0)
 		needRetry := false
-		storeIDsUnionSetForAllTasks := make(map[uint64]struct{})
 		for _, task := range tasks {
 			rpcCtx, err := cache.GetTiFlashRPCContext(bo.TiKVBackoffer(), task.region, isMPP, tikv.LabelFilterNoTiFlashWriteNode)
 			if err != nil {
 				return nil, errors.Trace(err)
 			}
+
 			// When rpcCtx is nil, it's not only attributed to the miss region, but also
 			// some TiFlash stores crash and can't be recovered.
 			// That is not an error that can be easily recovered, so we regard this error
@@ -941,36 +968,62 @@ func buildBatchCopTasksCore(bo *backoff.Backoffer, store *kvStore, rangesForEach
 				// Then `splitRegion` will reloads these regions.
 				continue
 			}
+
+			allStores, _ := cache.GetAllValidTiFlashStores(task.region, rpcCtx.Store, tikv.LabelFilterNoTiFlashWriteNode)
+			for _, storeID := range allStores {
+				usedTiFlashStoresMap[storeID] = struct{}{}
+			}
+			rpcCtxs = append(rpcCtxs, rpcCtx)
+			usedTiFlashStores = append(usedTiFlashStores, allStores)
+		}
+
+		if needRetry {
+			// As mentioned above, nil rpcCtx is always attributed to failed stores.
+			// It's equal to long poll the store but get no response. Here we'd better use
+			// TiFlash error to trigger the TiKV fallback mechanism.
+			err := bo.Backoff(tikv.BoTiFlashRPC(), errors.New("Cannot find region with TiFlash peer"))
+			if err != nil {
+				return nil, errors.Trace(err)
+			}
+			continue
+		}
+
+		aliveStores = getAliveStoresAndStoreIDs(bo.GetCtx(), cache, usedTiFlashStoresMap, ttl, store, tiflashReplicaReadPolicy, tidbZone)
+		if tiflashReplicaReadPolicy.IsClosestReplicas() {
+			if len(aliveStores.storeIDsInTiDBZone) == 0 {
+				return nil, errors.Errorf("There is no region in tidb zone(%s)", tidbZone)
+			}
+			maxRemoteReadCountAllowed = len(aliveStores.storeIDsInTiDBZone) * tiflash.MaxRemoteReadCountPerNodeForClosestReplicas
+		}
+
+		var batchTasks []*batchCopTask
+		var regionIDsInOtherZones []uint64
+		var regionInfosNeedReloadOnSendFail []RegionInfo
+		storeTaskMap := make(map[string]*batchCopTask)
+		storeIDsUnionSetForAllTasks := make(map[uint64]struct{})
+		for idx, task := range tasks {
+			var err error
 			var regionInfo RegionInfo
-			regionInfo, regionInfosNeedReloadOnSendFail, regionIDsInOtherZones, err = filterAccessibleStoresAndBuildRegionInfo(cache, bo, task, rpcCtx, aliveStores, isTiDBLabelZoneSet, tiflashReplicaReadPolicy, regionInfosNeedReloadOnSendFail, regionIDsInOtherZones, maxRemoteReadCountAllowed, tidbZone)
+			regionInfo, regionInfosNeedReloadOnSendFail, regionIDsInOtherZones, err = filterAccessibleStoresAndBuildRegionInfo(cache, usedTiFlashStores[idx], bo, task, rpcCtxs[idx], aliveStores, tiflashReplicaReadPolicy, regionInfosNeedReloadOnSendFail, regionIDsInOtherZones, maxRemoteReadCountAllowed, tidbZone)
 			if err != nil {
 				return nil, err
 			}
-			if batchCop, ok := storeTaskMap[rpcCtx.Addr]; ok {
+			if batchCop, ok := storeTaskMap[rpcCtxs[idx].Addr]; ok {
 				batchCop.regionInfos = append(batchCop.regionInfos, regionInfo)
 			} else {
 				batchTask := &batchCopTask{
-					storeAddr:   rpcCtx.Addr,
+					storeAddr:   rpcCtxs[idx].Addr,
 					cmdType:     cmdType,
-					ctx:         rpcCtx,
+					ctx:         rpcCtxs[idx],
 					regionInfos: []RegionInfo{regionInfo},
 				}
-				storeTaskMap[rpcCtx.Addr] = batchTask
+				storeTaskMap[rpcCtxs[idx].Addr] = batchTask
 			}
 			for _, storeID := range regionInfo.AllStores {
 				storeIDsUnionSetForAllTasks[storeID] = struct{}{}
 			}
 		}
-		if needRetry {
-			// As mentioned above, nil rpcCtx is always attributed to failed stores.
-			// It's equal to long poll the store but get no response. Here we'd better use
-			// TiFlash error to trigger the TiKV fallback mechanism.
-			err := bo.Backoff(tikv.BoTiFlashRPC(), errors.New("Cannot find region with TiFlash peer"))
-			if err != nil {
-				return nil, errors.Trace(err)
-			}
-			continue
-		}
+
 		if len(regionIDsInOtherZones) != 0 {
 			warningMsg := fmt.Sprintf("total %d region(s) can not be accessed by TiFlash in the zone [%s]:", len(regionIDsInOtherZones), tidbZone)
 			regionIDErrMsg := ""
@@ -998,7 +1051,7 @@ func buildBatchCopTasksCore(bo *backoff.Backoffer, store *kvStore, rangesForEach
 				storesUnionSetForAllTasks = append(storesUnionSetForAllTasks, store)
 			}
 		}
-		batchTasks = balanceBatchCopTask(bo.GetCtx(), storesUnionSetForAllTasks, batchTasks, balanceWithContinuity, balanceContinuousRegionCount)
+		batchTasks = balanceBatchCopTask(storesUnionSetForAllTasks, batchTasks, balanceWithContinuity, balanceContinuousRegionCount)
 		balanceElapsed := time.Since(balanceStart)
 		if log.GetLevel() <= zap.DebugLevel {
 			msg := "After region balance:"

pkg/store/copr/batch_coprocessor_test.go

@@ -23,12 +23,15 @@ import (
 	"time"
 
 	"github.com/pingcap/errors"
+	"github.com/pingcap/kvproto/pkg/metapb"
 	"github.com/pingcap/tidb/pkg/kv"
 	"github.com/pingcap/tidb/pkg/store/driver/backoff"
 	"github.com/pingcap/tidb/pkg/util/logutil"
 	"github.com/stathat/consistent"
 	"github.com/stretchr/testify/require"
+	"github.com/tikv/client-go/v2/testutils"
 	"github.com/tikv/client-go/v2/tikv"
+	"github.com/tikv/client-go/v2/tikvrpc"
 	"go.uber.org/zap"
 )
 
@@ -125,13 +128,13 @@ func TestBalanceBatchCopTaskWithContinuity(t *testing.T) {
 func TestBalanceBatchCopTaskWithEmptyTaskSet(t *testing.T) {
 	{
 		var nilTaskSet []*batchCopTask
-		nilResult := balanceBatchCopTask(nil, nil, nilTaskSet, false, 0)
+		nilResult := balanceBatchCopTask(nil, nilTaskSet, false, 0)
 		require.True(t, nilResult == nil)
 	}
 
 	{
 		emptyTaskSet := make([]*batchCopTask, 0)
-		emptyResult := balanceBatchCopTask(nil, nil, emptyTaskSet, false, 0)
+		emptyResult := balanceBatchCopTask(nil, emptyTaskSet, false, 0)
 		require.True(t, emptyResult != nil)
 		require.True(t, len(emptyResult) == 0)
 	}
@@ -282,3 +285,38 @@ func TestTopoFetcherBackoff(t *testing.T) {
 	require.GreaterOrEqual(t, dura, 30*time.Second)
 	require.LessOrEqual(t, dura, 50*time.Second)
 }
+
+func TestGetAllUsedTiFlashStores(t *testing.T) {
+	mockClient, _, pdClient, err := testutils.NewMockTiKV("", nil)
+	require.NoError(t, err)
+	defer func() {
+		pdClient.Close()
+		err = mockClient.Close()
+		require.NoError(t, err)
+	}()
+
+	pdCli := tikv.NewCodecPDClient(tikv.ModeTxn, pdClient)
+	defer pdCli.Close()
+
+	cache := NewRegionCache(tikv.NewRegionCache(pdCli))
+	defer cache.Close()
+
+	label1 := metapb.StoreLabel{Key: tikvrpc.EngineLabelKey, Value: tikvrpc.EngineLabelTiFlash}
+	label2 := metapb.StoreLabel{Key: tikvrpc.EngineRoleLabelKey, Value: tikvrpc.EngineLabelTiFlashCompute}
+
+	cache.SetRegionCacheStore(1, "192.168.1.1", "", tikvrpc.TiFlash, 1, []*metapb.StoreLabel{&label1, &label2})
+	cache.SetRegionCacheStore(2, "192.168.1.2", "192.168.1.3", tikvrpc.TiFlash, 1, []*metapb.StoreLabel{&label1, &label2})
+	cache.SetRegionCacheStore(3, "192.168.1.3", "192.168.1.2", tikvrpc.TiFlash, 1, []*metapb.StoreLabel{&label1, &label2})
+
+	allUsedTiFlashStoresMap := make(map[uint64]struct{})
+	allUsedTiFlashStoresMap[2] = struct{}{}
+	allUsedTiFlashStoresMap[3] = struct{}{}
+	allTiFlashStores := cache.RegionCache.GetTiFlashStores(tikv.LabelFilterNoTiFlashWriteNode)
+	require.Equal(t, 3, len(allTiFlashStores))
+	allUsedTiFlashStores := getAllUsedTiFlashStores(allTiFlashStores, allUsedTiFlashStoresMap)
+	require.Equal(t, len(allUsedTiFlashStoresMap), len(allUsedTiFlashStores))
+	for _, store := range allUsedTiFlashStores {
+		_, ok := allUsedTiFlashStoresMap[store.StoreID()]
+		require.True(t, ok)
+	}
+}