relay(dm): cancel when relay meet error to close goroutine

dm/relay/relay.go

@@ -574,7 +574,11 @@ func (r *Relay) handleEvents(
 		// 1. read events from upstream server
 		readTimer := time.Now()
 		rResult, err := reader2.GetEvent(ctx)
-		failpoint.Inject("RelayGetEventFailed", func(v failpoint.Value) {
+
+		failpoint.Inject("RelayGetEventFailed", func() {
+			err = errors.New("RelayGetEventFailed")
+		})
+		failpoint.Inject("RelayGetEventFailedAt", func(v failpoint.Value) {
 			if intVal, ok := v.(int); ok && intVal == eventIndex {
 				err = errors.New("fail point triggered")
 				_, gtid := r.meta.GTID()

dm/tests/duplicate_event/run.sh

@@ -41,7 +41,7 @@ function run_with_prepared_source_config() {
 
 	# with a 5 rows insert txn: 1 * FormatDesc + 1 * PreviousGTID + 1 * GTID + 1 * BEGIN + 5 * (Table_map + Write_rows) + 1 * XID
 	# here we fail at the third write rows event, sync should retry and auto recover without any duplicate event
-	export GO_FAILPOINTS="github.com/pingcap/tiflow/dm/relay/RelayGetEventFailed=return(3);github.com/pingcap/tiflow/dm/relay/RelayAllowRetry=return"
+	export GO_FAILPOINTS="github.com/pingcap/tiflow/dm/relay/RelayGetEventFailedAt=return(3);github.com/pingcap/tiflow/dm/relay/RelayAllowRetry=return"
 
 	run_dm_worker $WORK_DIR/worker2 $WORKER2_PORT $cur/conf/dm-worker2.toml
 	check_rpc_alive $cur/../bin/check_worker_online 127.0.0.1:$WORKER2_PORT

dm/tests/new_relay/run.sh

@@ -90,6 +90,38 @@ function test_restart_relay_status() {
 	echo ">>>>>>>>>>>>>>>>>>>>>>>>>>test test_restart_relay_status passed"
 }
 
+function test_relay_leak() {
+	cleanup_process
+	cleanup_data $TEST_NAME
+	export GO_FAILPOINTS="github.com/pingcap/tiflow/dm/relay/RelayGetEventFailed=return()"
+
+	run_dm_master $WORK_DIR/master $MASTER_PORT $cur/conf/dm-master.toml
+	check_rpc_alive $cur/../bin/check_master_online 127.0.0.1:$MASTER_PORT
+	run_dm_worker $WORK_DIR/worker1 $WORKER1_PORT $cur/conf/dm-worker1.toml
+	check_rpc_alive $cur/../bin/check_worker_online 127.0.0.1:$WORKER1_PORT
+
+	cp $cur/conf/source1.yaml $WORK_DIR/source1.yaml
+	sed -i "/check-enable: false/d" $WORK_DIR/source1.yaml
+	sed -i "/checker:/d" $WORK_DIR/source1.yaml
+	dmctl_operate_source create $WORK_DIR/source1.yaml $SOURCE_ID1
+
+	run_dm_ctl_with_retry $WORK_DIR "127.0.0.1:$MASTER_PORT" \
+		"start-relay -s $SOURCE_ID1 worker1"
+
+	run_dm_ctl_with_retry $WORK_DIR "127.0.0.1:$MASTER_PORT" \
+		"query-status -s $SOURCE_ID1" \
+		"RelayGetEventFailed" 1
+
+	check_log_contain_with_retry 'dispatch auto resume relay' $WORK_DIR/worker1/log/dm-worker.log
+
+	count=$(curl "http://127.0.0.1:8262/debug/pprof/goroutine?debug=2" 2>/dev/null | grep -c doIntervalOps || true)
+	if [ $count -gt 1 ]; then
+		echo "relay goroutine leak detected, count expect 1 but got $count"
+		exit 1
+	fi
+	echo ">>>>>>>>>>>>>>>>>>>>>>>>>>test test_cant_dail_upstream passed"
+}
+
 function test_cant_dail_upstream() {
 	cleanup_process
 	cleanup_data $TEST_NAME
@@ -356,6 +388,7 @@ function test_relay_operations() {
 }
 
 function run() {
+	test_relay_leak
 	test_relay_operations
 	test_cant_dail_upstream
 	test_restart_relay_status

dm/worker/relay.go

@@ -138,6 +138,7 @@ func (h *realRelayHolder) run() {
 	h.setResult(nil) // clear previous result
 
 	r := h.relay.Process(h.ctx)
+	h.cancel()
 
 	h.setResult(&r)
 	for _, err := range r.Errors {