unit(dm): add Kill func for unit (pingcap#4035)

close pingcap#3737

dm/dm/unit/unit.go

@@ -48,6 +48,8 @@ type Unit interface {
 	// Close shuts down the process and closes the unit, after that can not call Process to resume
 	// The implementation should not block for a long time.
 	Close()
+	// Kill shuts down the process and closes the unit without graceful.
+	Kill()
 	// Pause does some cleanups and the unit can be resumed later. The caller will make sure Process has returned.
 	// The implementation should not block for a long time.
 	Pause()

dm/dm/worker/hub_test.go

@@ -20,5 +20,5 @@ import (
 func (t *testServer) testConidtionHub(c *C, s *Server) {
 	// test condition hub
 	c.Assert(GetConditionHub(), NotNil)
-	c.Assert(GetConditionHub().w, DeepEquals, s.getWorker(true))
+	c.Assert(GetConditionHub().w, DeepEquals, s.getSourceWorker(true))
 }

dm/dm/worker/join.go

@@ -108,7 +108,8 @@ func (s *Server) KeepAlive() {
 		failpoint.Label("bypass")
 
 		// TODO: report the error.
-		err := s.stopWorker("", true)
+		// when lost keepalive, stop the worker without graceful. this is to fix https://github.com/pingcap/tiflow/issues/3737
+		err := s.stopSourceWorker("", true, false)
 		if err != nil {
 			log.L().Error("fail to stop worker", zap.Error(err))
 			return // return if failed to stop the worker.

dm/dm/worker/server.go

@@ -300,7 +300,7 @@ func (s *Server) observeRelayConfig(ctx context.Context, rev int64) error {
 					}
 					rev = rev1
 					if relaySource == nil {
-						if w := s.getWorker(true); w != nil && w.startedRelayBySourceCfg {
+						if w := s.getSourceWorker(true); w != nil && w.startedRelayBySourceCfg {
 							break
 						}
 						log.L().Info("didn't found relay config after etcd retryable error. Will stop relay now")
@@ -314,7 +314,7 @@ func (s *Server) observeRelayConfig(ctx context.Context, rev int64) error {
 							s.Lock()
 							defer s.Unlock()
 
-							if w := s.getWorker(false); w != nil && w.cfg.SourceID == relaySource.SourceID {
+							if w := s.getSourceWorker(false); w != nil && w.cfg.SourceID == relaySource.SourceID {
 								// we may face both relay config and subtask bound changed in a compaction error, so here
 								// we check if observeSourceBound has started a worker
 								// TODO: add a test for this situation
@@ -325,7 +325,7 @@ func (s *Server) observeRelayConfig(ctx context.Context, rev int64) error {
 								}
 								return nil
 							}
-							err = s.stopWorker("", false)
+							err = s.stopSourceWorker("", false, true)
 							if err != nil {
 								log.L().Error("fail to stop worker", zap.Error(err))
 								return err // return if failed to stop the worker.
@@ -403,7 +403,7 @@ func (s *Server) observeSourceBound(ctx context.Context, rev int64) error {
 							s.Lock()
 							defer s.Unlock()
 
-							if w := s.getWorker(false); w != nil && w.cfg.SourceID == bound.Source {
+							if w := s.getSourceWorker(false); w != nil && w.cfg.SourceID == bound.Source {
 								// we may face both relay config and subtask bound changed in a compaction error, so here
 								// we check if observeRelayConfig has started a worker
 								// TODO: add a test for this situation
@@ -414,7 +414,7 @@ func (s *Server) observeSourceBound(ctx context.Context, rev int64) error {
 								}
 								return nil
 							}
-							err = s.stopWorker("", false)
+							err = s.stopSourceWorker("", false, true)
 							if err != nil {
 								log.L().Error("fail to stop worker", zap.Error(err))
 								return err // return if failed to stop the worker.
@@ -441,30 +441,33 @@ func (s *Server) observeSourceBound(ctx context.Context, rev int64) error {
 }
 
 func (s *Server) doClose() {
-	s.cancel()
-	// close server in advance, stop receiving source bound and relay bound
-	s.wg.Wait()
-
 	s.Lock()
 	defer s.Unlock()
+
 	if s.closed.Load() {
 		return
 	}
-	// close worker and wait for return
-	if w := s.getWorker(false); w != nil {
-		w.Close()
+	// stop server in advance, stop receiving source bound and relay bound
+	s.cancel()
+	s.wg.Wait()
+	// stop worker and wait for return(we already lock the whole Sever, so no need use lock to get source worker)
+	if w := s.getSourceWorker(false); w != nil {
+		w.Stop(true)
 	}
 	s.closed.Store(true)
 }
 
 // Close close the RPC server, this function can be called multiple times.
 func (s *Server) Close() {
+	s.doClose() // we should stop current sync first, otherwise master may schedule task on new worker while we are closing
 	s.stopKeepAlive()
-	s.doClose()
+	if s.etcdClient != nil {
+		s.etcdClient.Close()
+	}
 }
 
 // if needLock is false, we should make sure Server has been locked in caller.
-func (s *Server) getWorker(needLock bool) *SourceWorker {
+func (s *Server) getSourceWorker(needLock bool) *SourceWorker {
 	if needLock {
 		s.Lock()
 		defer s.Unlock()
@@ -497,7 +500,7 @@ func (s *Server) setSourceStatus(source string, err error, needLock bool) {
 		defer s.Unlock()
 	}
 	// now setSourceStatus will be concurrently called. skip setting a source status if worker has been closed
-	if s.getWorker(false) == nil && source != "" {
+	if s.getSourceWorker(false) == nil && source != "" {
 		return
 	}
 	s.sourceStatus = pb.SourceStatus{
@@ -515,12 +518,12 @@ func (s *Server) setSourceStatus(source string, err error, needLock bool) {
 
 // if sourceID is set to "", worker will be closed directly
 // if sourceID is not "", we will check sourceID with w.cfg.SourceID.
-func (s *Server) stopWorker(sourceID string, needLock bool) error {
+func (s *Server) stopSourceWorker(sourceID string, needLock, graceful bool) error {
 	if needLock {
 		s.Lock()
 		defer s.Unlock()
 	}
-	w := s.getWorker(false)
+	w := s.getSourceWorker(false)
 	if w == nil {
 		log.L().Warn("worker has not been started, no need to stop", zap.String("source", sourceID))
 		return nil // no need to stop because not started yet
@@ -531,7 +534,7 @@ func (s *Server) stopWorker(sourceID string, needLock bool) error {
 	s.UpdateKeepAliveTTL(s.cfg.KeepAliveTTL)
 	s.setWorker(nil, false)
 	s.setSourceStatus("", nil, false)
-	w.Close()
+	w.Stop(graceful)
 	return nil
 }
 
@@ -659,7 +662,7 @@ func (s *Server) enableHandleSubtasks(sourceCfg *config.SourceConfig, needLock b
 func (s *Server) disableHandleSubtasks(source string) error {
 	s.Lock()
 	defer s.Unlock()
-	w := s.getWorker(false)
+	w := s.getSourceWorker(false)
 	if w == nil {
 		log.L().Warn("worker has already stopped before DisableHandleSubtasks", zap.String("source", source))
 		return nil
@@ -676,7 +679,7 @@ func (s *Server) disableHandleSubtasks(source string) error {
 	var err error
 	if !w.relayEnabled.Load() {
 		log.L().Info("relay is not enabled after disabling subtask, so stop worker")
-		err = s.stopWorker(source, false)
+		err = s.stopSourceWorker(source, false, true)
 	}
 	return err
 }
@@ -721,7 +724,7 @@ func (s *Server) enableRelay(sourceCfg *config.SourceConfig, needLock bool) erro
 func (s *Server) disableRelay(source string) error {
 	s.Lock()
 	defer s.Unlock()
-	w := s.getWorker(false)
+	w := s.getSourceWorker(false)
 	if w == nil {
 		log.L().Warn("worker has already stopped before DisableRelay", zap.Any("relaySource", source))
 		return nil
@@ -731,7 +734,7 @@ func (s *Server) disableRelay(source string) error {
 	var err error
 	if !w.subTaskEnabled.Load() {
 		log.L().Info("subtask is not enabled after disabling relay, so stop worker")
-		err = s.stopWorker(source, false)
+		err = s.stopSourceWorker(source, false, true)
 	}
 	return err
 }
@@ -747,7 +750,7 @@ func (s *Server) QueryStatus(ctx context.Context, req *pb.QueryStatusRequest) (*
 		SourceStatus: &sourceStatus,
 	}
 
-	w := s.getWorker(true)
+	w := s.getSourceWorker(true)
 	if w == nil {
 		log.L().Warn("fail to call QueryStatus, because no mysql source is being handled in the worker")
 		resp.Result = false
@@ -769,7 +772,7 @@ func (s *Server) QueryStatus(ctx context.Context, req *pb.QueryStatusRequest) (*
 // PurgeRelay implements WorkerServer.PurgeRelay.
 func (s *Server) PurgeRelay(ctx context.Context, req *pb.PurgeRelayRequest) (*pb.CommonWorkerResponse, error) {
 	log.L().Info("", zap.String("request", "PurgeRelay"), zap.Stringer("payload", req))
-	w := s.getWorker(true)
+	w := s.getSourceWorker(true)
 	if w == nil {
 		log.L().Warn("fail to call StartSubTask, because no mysql source is being handled in the worker")
 		return makeCommonWorkerResponse(terror.ErrWorkerNoStart.Generate()), nil
@@ -786,7 +789,7 @@ func (s *Server) PurgeRelay(ctx context.Context, req *pb.PurgeRelayRequest) (*pb
 func (s *Server) OperateSchema(ctx context.Context, req *pb.OperateWorkerSchemaRequest) (*pb.CommonWorkerResponse, error) {
 	log.L().Info("", zap.String("request", "OperateSchema"), zap.Stringer("payload", req))
 
-	w := s.getWorker(true)
+	w := s.getSourceWorker(true)
 	if w == nil {
 		log.L().Warn("fail to call OperateSchema, because no mysql source is being handled in the worker")
 		return makeCommonWorkerResponse(terror.ErrWorkerNoStart.Generate()), nil
@@ -813,7 +816,7 @@ func (s *Server) getOrStartWorker(cfg *config.SourceConfig, needLock bool) (*Sou
 		defer s.Unlock()
 	}
 
-	if w := s.getWorker(false); w != nil {
+	if w := s.getSourceWorker(false); w != nil {
 		if w.cfg.SourceID == cfg.SourceID {
 			log.L().Info("mysql source is being handled", zap.String("sourceID", s.worker.cfg.SourceID))
 			return w, nil
@@ -904,7 +907,7 @@ func getMinLocForSubTask(ctx context.Context, subTaskCfg config.SubTaskConfig) (
 func (s *Server) HandleError(ctx context.Context, req *pb.HandleWorkerErrorRequest) (*pb.CommonWorkerResponse, error) {
 	log.L().Info("", zap.String("request", "HandleError"), zap.Stringer("payload", req))
 
-	w := s.getWorker(true)
+	w := s.getSourceWorker(true)
 	if w == nil {
 		log.L().Warn("fail to call HandleError, because no mysql source is being handled in the worker")
 		return makeCommonWorkerResponse(terror.ErrWorkerNoStart.Generate()), nil

dm/dm/worker/server_test.go

@@ -208,7 +208,7 @@ func (t *testServer) TestServer(c *C) {
 	_, err = ha.DeleteSubTaskStage(s.etcdClient, ha.NewSubTaskStage(pb.Stage_Stopped, sourceCfg.SourceID, subtaskCfg.Name))
 	c.Assert(err, IsNil)
 	c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
-		return s.getWorker(true).subTaskHolder.findSubTask(subtaskCfg.Name) == nil
+		return s.getSourceWorker(true).subTaskHolder.findSubTask(subtaskCfg.Name) == nil
 	}), IsTrue)
 
 	dupServer := NewServer(cfg)
@@ -337,13 +337,13 @@ func (t *testServer) TestHandleSourceBoundAfterError(c *C) {
 	_, err = ha.PutSourceCfg(etcdCli, sourceCfg)
 	c.Assert(err, IsNil)
 	c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
-		return s.getWorker(true) != nil
+		return s.getSourceWorker(true) != nil
 	}), IsTrue)
 
 	_, err = ha.DeleteSourceBound(etcdCli, s.cfg.Name)
 	c.Assert(err, IsNil)
 	c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
-		return s.getWorker(true) == nil
+		return s.getSourceWorker(true) == nil
 	}), IsTrue)
 }
 
@@ -413,19 +413,19 @@ func (t *testServer) TestWatchSourceBoundEtcdCompact(c *C) {
 	}()
 	// step 4.1: should stop the running worker, source bound has been deleted, should stop this worker
 	c.Assert(utils.WaitSomething(20, 100*time.Millisecond, func() bool {
-		return s.getWorker(true) == nil
+		return s.getSourceWorker(true) == nil
 	}), IsTrue)
 	// step 4.2: put a new source bound, source should be started
 	_, err = ha.PutSourceBound(etcdCli, sourceBound)
 	c.Assert(err, IsNil)
 	c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
-		return s.getWorker(true) != nil
+		return s.getSourceWorker(true) != nil
 	}), IsTrue)
-	cfg2 := s.getWorker(true).cfg
+	cfg2 := s.getSourceWorker(true).cfg
 	c.Assert(cfg2, DeepEquals, sourceCfg)
 	cancel1()
 	wg.Wait()
-	c.Assert(s.stopWorker(sourceCfg.SourceID, true), IsNil)
+	c.Assert(s.stopSourceWorker(sourceCfg.SourceID, true, true), IsNil)
 	// step 5: start observeSourceBound from compacted revision again, should start worker
 	ctx2, cancel2 := context.WithCancel(ctx)
 	wg.Add(1)
@@ -434,9 +434,9 @@ func (t *testServer) TestWatchSourceBoundEtcdCompact(c *C) {
 		c.Assert(s.observeSourceBound(ctx2, startRev), IsNil)
 	}()
 	c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
-		return s.getWorker(true) != nil
+		return s.getSourceWorker(true) != nil
 	}), IsTrue)
-	cfg2 = s.getWorker(true).cfg
+	cfg2 = s.getSourceWorker(true).cfg
 	c.Assert(cfg2, DeepEquals, sourceCfg)
 	cancel2()
 	wg.Wait()
@@ -480,13 +480,13 @@ func (t *testServer) testOperateWorker(c *C, s *Server, dir string, start bool)
 		c.Assert(err, IsNil)
 		// worker should be started and without error
 		c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
-			w := s.getWorker(true)
+			w := s.getSourceWorker(true)
 			return w != nil && !w.closed.Load()
 		}), IsTrue)
 		c.Assert(s.getSourceStatus(true).Result, IsNil)
 	} else {
 		// worker should be started before stopped
-		w := s.getWorker(true)
+		w := s.getSourceWorker(true)
 		c.Assert(w, NotNil)
 		c.Assert(w.closed.Load(), IsFalse)
 		_, err := ha.DeleteRelayConfig(s.etcdClient, w.name)
@@ -495,7 +495,7 @@ func (t *testServer) testOperateWorker(c *C, s *Server, dir string, start bool)
 		c.Assert(err, IsNil)
 		// worker should be closed and without error
 		c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
-			currentWorker := s.getWorker(true)
+			currentWorker := s.getSourceWorker(true)
 			return currentWorker == nil && w.closed.Load()
 		}), IsTrue)
 		c.Assert(s.getSourceStatus(true).Result, IsNil)
@@ -506,7 +506,7 @@ func (t *testServer) testRetryConnectMaster(c *C, s *Server, etcd *embed.Etcd, d
 	etcd.Close()
 	time.Sleep(6 * time.Second)
 	// When worker server fail to keepalive with etcd, server should close its worker
-	c.Assert(s.getWorker(true), IsNil)
+	c.Assert(s.getSourceWorker(true), IsNil)
 	c.Assert(s.getSourceStatus(true).Result, IsNil)
 	ETCD, err := createMockETCD(dir, "http://"+hostName)
 	c.Assert(err, IsNil)
@@ -551,9 +551,9 @@ func (t *testServer) testSubTaskRecover(c *C, s *Server, dir string) {
 func (t *testServer) testStopWorkerWhenLostConnect(c *C, s *Server, etcd *embed.Etcd) {
 	etcd.Close()
 	c.Assert(utils.WaitSomething(int(defaultKeepAliveTTL+3), time.Second, func() bool {
-		return s.getWorker(true) == nil
+		return s.getSourceWorker(true) == nil
 	}), IsTrue)
-	c.Assert(s.getWorker(true), IsNil)
+	c.Assert(s.getSourceWorker(true), IsNil)
 }
 
 func (t *testServer) TestGetMinLocInAllSubTasks(c *C) {

dm/dm/worker/source_worker.go

@@ -203,7 +203,7 @@ func (w *SourceWorker) Start() {
 }
 
 // Close stops working and releases resources.
-func (w *SourceWorker) Close() {
+func (w *SourceWorker) Stop(graceful bool) {
 	if w.closed.Load() {
 		w.l.Warn("already closed")
 		return
@@ -218,8 +218,12 @@ func (w *SourceWorker) Close() {
 	w.Lock()
 	defer w.Unlock()
 
-	// close all sub tasks
-	w.subTaskHolder.closeAllSubTasks()
+	// close or kill all subtasks
+	if graceful {
+		w.subTaskHolder.closeAllSubTasks()
+	} else {
+		w.subTaskHolder.killAllSubTasks()
+	}
 
 	if w.relayHolder != nil {
 		w.relayHolder.Close()