scheduler: fix scheduler save config

pkg/schedule/schedulers/evict_leader.go

@@ -181,7 +181,7 @@ func newEvictLeaderScheduler(opController *operator.Controller, conf *evictLeade
 	}
 }
 
-// EvictStores returns the IDs of the evict-stores.
+// EvictStoreIDs returns the IDs of the evict-stores.
 func (s *evictLeaderScheduler) EvictStoreIDs() []uint64 {
 	return s.conf.getStores()
 }

pkg/schedule/schedulers/scheduler.go

@@ -124,16 +124,16 @@
 		return nil, errs.ErrSchedulerCreateFuncNotRegistered.FastGenByArgs(typ)
 	}
 
-	s, err := fn(oc, storage, dec, removeSchedulerCb...)
-	if err != nil {
-		return nil, err
-	}
+	return fn(oc, storage, dec, removeSchedulerCb...)
+}
+
+// SaveSchedulerConfig saves the config of the specified scheduler.
+func SaveSchedulerConfig(storage endpoint.ConfigStorage, s Scheduler) error {
 	data, err := s.EncodeConfig()
 	if err != nil {
-		return nil, err
+		return err
 	}
-	err = storage.SaveSchedulerConfig(s.GetName(), data)
-	return s, err
+	return storage.SaveSchedulerConfig(s.GetName(), data)
 }
 
 // FindSchedulerTypeByName finds the type of the specified name.

pkg/schedule/schedulers/scheduler_controller.go

@@ -138,6 +138,10 @@
 	}
 
 	c.schedulerHandlers[name] = scheduler
+	if err := SaveSchedulerConfig(c.storage, scheduler); err != nil {
+		log.Error("can not save HTTP scheduler config", zap.String("scheduler-name", scheduler.GetName()), errs.ZapError(err))
+		return err
+	}
 	c.cluster.GetSchedulerConfig().AddSchedulerCfg(scheduler.GetType(), args)
 	return nil
 }
@@ -188,6 +192,10 @@
 	c.wg.Add(1)
 	go c.runScheduler(s)
 	c.schedulers[s.Scheduler.GetName()] = s
+	if err := SaveSchedulerConfig(c.storage, scheduler); err != nil {
+		log.Error("can not save scheduler config", zap.String("scheduler-name", scheduler.GetName()), errs.ZapError(err))
+		return err
+	}
 	c.cluster.GetSchedulerConfig().AddSchedulerCfg(s.Scheduler.GetType(), args)
 	return nil
 }

server/cluster/cluster_test.go

@@ -3111,8 +3111,9 @@ func TestPersistScheduler(t *testing.T) {
 	// whether the schedulers added or removed in dynamic way are recorded in opt
 	_, newOpt, err := newTestScheduleConfig()
 	re.NoError(err)
-	_, err = schedulers.CreateScheduler(schedulers.ShuffleRegionType, oc, storage, schedulers.ConfigJSONDecoder([]byte("null")))
+	shuffle, err := schedulers.CreateScheduler(schedulers.ShuffleRegionType, oc, storage, schedulers.ConfigJSONDecoder([]byte("null")))
 	re.NoError(err)
+	re.NoError(controller.AddScheduler(shuffle))
 	// suppose we add a new default enable scheduler
 	sc.DefaultSchedulers = append(sc.DefaultSchedulers, sc.SchedulerConfig{Type: "shuffle-region"})
 	defer func() {

tests/server/cluster/cluster_test.go

@@ -37,6 +37,7 @@ import (
 	"github.com/tikv/pd/pkg/mock/mockid"
 	sc "github.com/tikv/pd/pkg/schedule/config"
 	"github.com/tikv/pd/pkg/schedule/operator"
+	"github.com/tikv/pd/pkg/schedule/schedulers"
 	"github.com/tikv/pd/pkg/storage"
 	"github.com/tikv/pd/pkg/syncer"
 	"github.com/tikv/pd/pkg/tso"
@@ -47,6 +48,7 @@ import (
 	"github.com/tikv/pd/server/cluster"
 	"github.com/tikv/pd/server/config"
 	"github.com/tikv/pd/tests"
+	"github.com/tikv/pd/tests/server/api"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -1275,6 +1277,119 @@ func TestStaleTermHeartbeat(t *testing.T) {
 	re.NoError(err)
 }
 
+func TestTransferLeaderForScheduler(t *testing.T) {
+	re := require.New(t)
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	re.NoError(failpoint.Enable("github.com/tikv/pd/pkg/schedule/changeCoordinatorTicker", `return(true)`))
+	tc, err := tests.NewTestCluster(ctx, 2)
+	defer tc.Destroy()
+	re.NoError(err)
+	err = tc.RunInitialServers()
+	re.NoError(err)
+	tc.WaitLeader()
+	// start
+	leaderServer := tc.GetServer(tc.GetLeader())
+	re.NoError(leaderServer.BootstrapCluster())
+	rc := leaderServer.GetServer().GetRaftCluster()
+	re.NotNil(rc)
+
+	storesNum := 2
+	grpcPDClient := testutil.MustNewGrpcClient(re, leaderServer.GetAddr())
+	for i := 1; i <= storesNum; i++ {
+		store := &metapb.Store{
+			Id:      uint64(i),
+			Address: "127.0.0.1:" + strconv.Itoa(i),
+		}
+		resp, err := putStore(grpcPDClient, leaderServer.GetClusterID(), store)
+		re.NoError(err)
+		re.Equal(pdpb.ErrorType_OK, resp.GetHeader().GetError().GetType())
+	}
+	// region heartbeat
+	id := leaderServer.GetAllocator()
+	putRegionWithLeader(re, rc, id, 1)
+
+	time.Sleep(time.Second)
+	re.True(leaderServer.GetRaftCluster().IsPrepared())
+	// Add evict leader scheduler
+	api.MustAddScheduler(re, leaderServer.GetAddr(), schedulers.EvictLeaderName, map[string]interface{}{
+		"store_id": 1,
+	})
+	api.MustAddScheduler(re, leaderServer.GetAddr(), schedulers.EvictLeaderName, map[string]interface{}{
+		"store_id": 2,
+	})
+	// Check scheduler updated.
+	schedulersController := rc.GetCoordinator().GetSchedulersController()
+	re.Len(schedulersController.GetSchedulerNames(), 6)
+	checkEvictLeaderSchedulerExist(re, schedulersController, true)
+	checkEvictLeaderStoreIDs(re, schedulersController, []uint64{1, 2})
+
+	// transfer PD leader to another PD
+	tc.ResignLeader()
+	rc.Stop()
+	tc.WaitLeader()
+	leaderServer = tc.GetServer(tc.GetLeader())
+	rc1 := leaderServer.GetServer().GetRaftCluster()
+	rc1.Start(leaderServer.GetServer())
+	re.NoError(err)
+	re.NotNil(rc1)
+	// region heartbeat
+	id = leaderServer.GetAllocator()
+	putRegionWithLeader(re, rc1, id, 1)
+	time.Sleep(time.Second)
+	re.True(leaderServer.GetRaftCluster().IsPrepared())
+	// Check scheduler updated.
+	schedulersController = rc1.GetCoordinator().GetSchedulersController()
+	re.Len(schedulersController.GetSchedulerNames(), 6)
+	checkEvictLeaderSchedulerExist(re, schedulersController, true)
+	checkEvictLeaderStoreIDs(re, schedulersController, []uint64{1, 2})
+
+	// transfer PD leader back to the previous PD
+	tc.ResignLeader()
+	rc1.Stop()
+	tc.WaitLeader()
+	leaderServer = tc.GetServer(tc.GetLeader())
+	rc = leaderServer.GetServer().GetRaftCluster()
+	rc.Start(leaderServer.GetServer())
+	re.NotNil(rc)
+	// region heartbeat
+	id = leaderServer.GetAllocator()
+	putRegionWithLeader(re, rc, id, 1)
+	time.Sleep(time.Second)
+	re.True(leaderServer.GetRaftCluster().IsPrepared())
+	// Check scheduler updated
+	schedulersController = rc.GetCoordinator().GetSchedulersController()
+	re.Len(schedulersController.GetSchedulerNames(), 6)
+	checkEvictLeaderSchedulerExist(re, schedulersController, true)
+	checkEvictLeaderStoreIDs(re, schedulersController, []uint64{1, 2})
+
+	re.NoError(failpoint.Disable("github.com/tikv/pd/pkg/schedule/changeCoordinatorTicker"))
+}
+
+func checkEvictLeaderSchedulerExist(re *require.Assertions, sc *schedulers.Controller, exist bool) {
+	testutil.Eventually(re, func() bool {
+		if !exist {
+			return sc.GetScheduler(schedulers.EvictLeaderName) == nil
+		}
+		return sc.GetScheduler(schedulers.EvictLeaderName) != nil
+	})
+}
+
+func checkEvictLeaderStoreIDs(re *require.Assertions, sc *schedulers.Controller, expected []uint64) {
+	handler, ok := sc.GetSchedulerHandlers()[schedulers.EvictLeaderName]
+	re.True(ok)
+	h, ok := handler.(interface {
+		EvictStoreIDs() []uint64
+	})
+	re.True(ok)
+	var evictStoreIDs []uint64
+	testutil.Eventually(re, func() bool {
+		evictStoreIDs = h.EvictStoreIDs()
+		return len(evictStoreIDs) == len(expected)
+	})
+	re.ElementsMatch(evictStoreIDs, expected)
+}
+
 func putRegionWithLeader(re *require.Assertions, rc *cluster.RaftCluster, id id.Allocator, storeID uint64) {
 	for i := 0; i < 3; i++ {
 		regionID, err := id.Alloc()