Stop infinite goroutines

Author: Nikhil Mathew

go/logic/applier.go

@@ -30,16 +30,18 @@ const (
 // Applier is the one to actually write row data and apply binlog events onto the ghost table.
 // It is where the ghost & changelog tables get created. It is where the cut-over phase happens.
 type Applier struct {
-	connectionConfig *mysql.ConnectionConfig
-	db               *gosql.DB
-	singletonDB      *gosql.DB
-	migrationContext *base.MigrationContext
+	connectionConfig  *mysql.ConnectionConfig
+	db                *gosql.DB
+	singletonDB       *gosql.DB
+	migrationContext  *base.MigrationContext
+	finishedMigrating bool
 }
 
 func NewApplier(migrationContext *base.MigrationContext) *Applier {
 	return &Applier{
-		connectionConfig: migrationContext.ApplierConnectionConfig,
-		migrationContext: migrationContext,
+		connectionConfig:  migrationContext.ApplierConnectionConfig,
+		migrationContext:  migrationContext,
+		finishedMigrating: false,
 	}
 }
 
@@ -288,6 +290,10 @@ func (this *Applier) WriteChangelogState(value string) (string, error) {
 	return this.WriteAndLogChangelog("state", value)
 }
 
+func (this *Applier) FinalCleanup() {
+	this.finishedMigrating = true
+}
+
 // InitiateHeartbeat creates a heartbeat cycle, writing to the changelog table.
 // This is done asynchronously
 func (this *Applier) InitiateHeartbeat() {
@@ -310,6 +316,9 @@ func (this *Applier) InitiateHeartbeat() {
 
 	heartbeatTick := time.Tick(time.Duration(this.migrationContext.HeartbeatIntervalMilliseconds) * time.Millisecond)
 	for range heartbeatTick {
+		if this.finishedMigrating {
+			return
+		}
 		// Generally speaking, we would issue a goroutine, but I'd actually rather
 		// have this block the loop rather than spam the master in the event something
 		// goes wrong

go/logic/migrator.go

@@ -83,6 +83,8 @@ type Migrator struct {
 	applyEventsQueue chan *applyEventStruct
 
 	handledChangelogStates map[string]bool
+
+	finishedMigrating bool
 }
 
 func NewMigrator(context *base.MigrationContext) *Migrator {
@@ -97,6 +99,7 @@ func NewMigrator(context *base.MigrationContext) *Migrator {
 		copyRowsQueue:          make(chan tableWriteFunc),
 		applyEventsQueue:       make(chan *applyEventStruct, base.MaxEventsBatchSize),
 		handledChangelogStates: make(map[string]bool),
+		finishedMigrating:      false,
 	}
 	return migrator
 }
@@ -718,6 +721,9 @@ func (this *Migrator) initiateStatus() error {
 	this.printStatus(ForcePrintStatusAndHintRule)
 	statusTick := time.Tick(1 * time.Second)
 	for range statusTick {
+		if this.finishedMigrating {
+			return nil
+		}
 		go this.printStatus(HeuristicPrintStatusRule)
 	}
 
@@ -942,6 +948,9 @@ func (this *Migrator) initiateStreaming() error {
 	go func() {
 		ticker := time.Tick(1 * time.Second)
 		for range ticker {
+			if this.finishedMigrating {
+				return
+			}
 			this.migrationContext.SetRecentBinlogCoordinates(*this.eventsStreamer.GetCurrentBinlogCoordinates())
 		}
 	}()
@@ -1132,6 +1141,10 @@ func (this *Migrator) executeWriteFuncs() error {
 		return nil
 	}
 	for {
+		if this.finishedMigrating {
+			return nil
+		}
+
 		this.throttler.throttle(nil)
 
 		// We give higher priority to event processing, then secondary priority to
@@ -1209,5 +1222,8 @@ func (this *Migrator) finalCleanup() error {
 		}
 	}
 
+	this.finishedMigrating = true
+	this.applier.FinalCleanup()
+
 	return nil
 }