Fix unsaved event regression

go/test/endtoend/vreplication/helper.go

@@ -241,3 +241,14 @@ func expectNumberOfStreams(t *testing.T, vtgateConn *mysql.Conn, name string, wo
 		t.Fatalf("Incorrect streams found for %s: %s\n", name, result)
 	}
 }
+
+func printShardPositions(vc *VitessCluster, ksShards []string) {
+	for _, ksShard := range ksShards {
+		output, err := vc.VtctlClient.ExecuteCommandWithOutput("ShardReplicationPositions", ksShard)
+		if err != nil {
+			fmt.Printf("Error in ShardReplicationPositions: %v, output %v", err, output)
+		} else {
+			fmt.Printf("Position of %s: %s", ksShard, output)
+		}
+	}
+}

go/test/endtoend/vreplication/vreplication_test.go

@@ -186,6 +186,7 @@ func insertMoreCustomers(t *testing.T, numCustomers int) {
 	execVtgateQuery(t, vtgateConn, "customer", sql)
 }
 
+// FIXME: if testReverse if false we don't dropsources and that creates a problem later on in the test due to existence of blacklisted tables
 func shardCustomer(t *testing.T, testReverse bool, cells []*Cell, sourceCellOrAlias string) {
 	if _, err := vc.AddKeyspace(t, cells, "customer", "-80,80-", customerVSchema, customerSchema, defaultReplicas, defaultRdonly, 200); err != nil {
 		t.Fatal(err)
@@ -250,6 +251,8 @@ func shardCustomer(t *testing.T, testReverse bool, cells []*Cell, sourceCellOrAl
 	if output, err := vc.VtctlClient.ExecuteCommandWithOutput("SwitchWrites", "customer.p2c"); err != nil {
 		t.Fatalf("SwitchWrites error: %s\n", output)
 	}
+	ksShards := []string{"product/0", "customer/-80", "customer/80-"}
+	printShardPositions(vc, ksShards)
 	insertQuery2 := "insert into customer(name) values('tempCustomer2')"
 	matchInsertQuery2 := "insert into customer(name, cid) values (:vtg1, :_cid0)"
 	assert.False(t, validateThatQueryExecutesOnTablet(t, vtgateConn, productTab, "customer", insertQuery2, matchInsertQuery2))
@@ -268,11 +271,13 @@ func shardCustomer(t *testing.T, testReverse bool, cells []*Cell, sourceCellOrAl
 		if output, err := vc.VtctlClient.ExecuteCommandWithOutput("SwitchReads", "-cells="+allCellNames, "-tablet_type=replica", "product.p2c_reverse"); err != nil {
 			t.Fatalf("SwitchReads error: %s\n", output)
 		}
+		printShardPositions(vc, ksShards)
 		if output, err := vc.VtctlClient.ExecuteCommandWithOutput("SwitchWrites", "product.p2c_reverse"); err != nil {
 			t.Fatalf("SwitchWrites error: %s\n", output)
 		}
 		insertQuery1 = "insert into customer(cid, name) values(1002, 'tempCustomer5')"
 		assert.True(t, validateThatQueryExecutesOnTablet(t, vtgateConn, productTab, "product", insertQuery1, matchInsertQuery1))
+		// both inserts go into 80-, this tests the edge-case where a stream (-80) has no relevant new events after the previous switch
 		insertQuery1 = "insert into customer(cid, name) values(1003, 'tempCustomer6')"
 		assert.False(t, validateThatQueryExecutesOnTablet(t, vtgateConn, customerTab1, "customer", insertQuery1, matchInsertQuery1))
 		insertQuery1 = "insert into customer(cid, name) values(1004, 'tempCustomer7')"

go/vt/vttablet/tabletmanager/vreplication/vplayer.go

@@ -251,8 +251,6 @@ func (vp *vplayer) updateTime(ts int64) (err error) {
 	if _, err := vp.vr.dbClient.Execute(update); err != nil {
 		return fmt.Errorf("error %v updating time", err)
 	}
-	vp.unsavedEvent = nil
-	vp.timeLastSaved = time.Now()
 	return nil
 }
 

go/vt/wrangler/traffic_switcher.go

@@ -741,14 +741,18 @@ func (ts *trafficSwitcher) waitForCatchup(ctx context.Context, filteredReplicati
 
 	var mu sync.Mutex
 	return ts.forAllUids(func(target *tsTarget, uid uint32) error {
+		ts.wr.Logger().Infof("uid: %d, target master %s, target position %s, shard %s", uid,
+			target.master.AliasString(), target.position, target.si.String())
 		bls := target.sources[uid]
 		source := ts.sources[bls.Shard]
-		ts.wr.Logger().Infof("waiting for keyspace:shard: %v:%v, position %v", ts.targetKeyspace, target.si.ShardName(), source.position)
+		ts.wr.Logger().Infof("waiting for keyspace:shard: %v:%v, source position %v, uid %d",
+			ts.targetKeyspace, target.si.ShardName(), source.position, uid)
 		if err := ts.wr.tmc.VReplicationWaitForPos(ctx, target.master.Tablet, int(uid), source.position); err != nil {
 			return err
 		}
-		ts.wr.Logger().Infof("position for keyspace:shard: %v:%v reached", ts.targetKeyspace, target.si.ShardName())
+		ts.wr.Logger().Infof("position for keyspace:shard: %v:%v reached, uid %d", ts.targetKeyspace, target.si.ShardName(), uid)
 		if _, err := ts.wr.tmc.VReplicationExec(ctx, target.master.Tablet, binlogplayer.StopVReplication(uid, "stopped for cutover")); err != nil {
+			log.Infof("error marking stopped for cutover on %s, uid %d", target.master.AliasString(), uid)
 			return err
 		}
 
@@ -760,7 +764,7 @@ func (ts *trafficSwitcher) waitForCatchup(ctx context.Context, filteredReplicati
 		}
 		var err error
 		target.position, err = ts.wr.tmc.MasterPosition(ctx, target.master.Tablet)
-		ts.wr.Logger().Infof("Position for uid %v: %v", uid, target.position)
+		ts.wr.Logger().Infof("Position for target master %s, uid %v: %v", target.master.AliasString(), uid, target.position)
 		return err
 	})
 }