resolve conflicts

Signed-off-by: Ryan Leung <[email protected]>

client/tso_dispatcher.go

@@ -443,7 +443,7 @@ func (td *tsoDispatcher) handleProcessRequestError(ctx context.Context, bo *retr
 	td.connectionCtxs.Delete(streamURL)
 	streamCancelFunc()
 	if errs.IsServiceModeChange(err) {
-		svcDiscovery.ScheduleServiceModeChanged()
+		svcDiscovery.ScheduleCheckServiceModeChanged()
 		return false
 	}
 	// Because ScheduleCheckMemberChanged is asynchronous, if the leader changes, we better call `updateMember` ASAP.

tests/integrations/mcs/tso/server_test.go

@@ -641,3 +641,68 @@ func TestTSOServiceSwitch(t *testing.T) {
 	<-ch
 	re.NoError(failpoint.Disable("github.com/tikv/pd/client/fastUpdateServiceMode"))
 }
+
+func TestTSOServiceWithOldClient(t *testing.T) {
+	re := require.New(t)
+	re.NoError(failpoint.Enable("github.com/tikv/pd/client/fastUpdateServiceMode", `return(true)`))
+	re.NoError(failpoint.Enable("github.com/tikv/pd/client/usePDServiceMode", `return(true)`))
+	var wg sync.WaitGroup
+	defer wg.Wait()
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	cluster, err := tests.NewTestAPICluster(ctx, 1)
+	re.NoError(err)
+	defer cluster.Destroy()
+
+	err = cluster.RunInitialServers()
+	re.NoError(err)
+
+	leaderName := cluster.WaitLeader()
+	re.NotEmpty(leaderName)
+	pdLeader := cluster.GetServer(leaderName)
+	backendEndpoints := pdLeader.GetAddr()
+	re.NoError(pdLeader.BootstrapCluster())
+	pdClient, err := pd.NewClientWithContext(ctx, []string{backendEndpoints}, pd.SecurityOption{})
+	re.NoError(err)
+	defer pdClient.Close()
+	ch := make(chan struct{})
+	ch1 := make(chan struct{})
+	wg.Add(1)
+	go func(ctx context.Context, wg *sync.WaitGroup, ch, ch1 chan struct{}) {
+		defer wg.Done()
+		var lastPhysical, lastLogical int64
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			default:
+			}
+			physical, logical, err := pdClient.GetTS(context.Background())
+			if err == nil {
+				re.GreaterOrEqual(physical, lastPhysical)
+				if physical == lastPhysical {
+					re.Greater(logical, lastLogical)
+				}
+				lastPhysical = physical
+				lastLogical = logical
+				select {
+				case <-ch1:
+					ch <- struct{}{}
+				default:
+				}
+			} else {
+				t.Log(err)
+			}
+		}
+	}(ctx, &wg, ch, ch1)
+	ch1 <- struct{}{}
+	<-ch
+	tsoCluster, err := tests.NewTestTSOCluster(ctx, 1, backendEndpoints)
+	re.NoError(err)
+	tsoCluster.WaitForDefaultPrimaryServing(re)
+	ch1 <- struct{}{}
+	<-ch
+	tsoCluster.Destroy()
+	re.NoError(failpoint.Disable("github.com/tikv/pd/client/usePDServiceMode"))
+	re.NoError(failpoint.Disable("github.com/tikv/pd/client/fastUpdateServiceMode"))
+}