Fix convertBoolToSemiSyncAction method to account for all semi sync actions

Signed-off-by: William Lu <[email protected]>

Author: WilliamLu99

go/test/endtoend/reparent/plannedreparent/reparent_test.go

@@ -360,6 +360,41 @@ func TestChangeTypeSemiSync(t *testing.T) {
 	utils.CheckDBstatus(ctx, t, rdonly2, "Rpl_semi_sync_slave_status", "ON")
 }
 
+// Tests that ChangeTabletType works even when semi-sync plugins are not loaded.
+func TestChangeTypeWithoutSemiSync(t *testing.T) {
+	defer cluster.PanicHandler(t)
+	clusterInstance := utils.SetupReparentCluster(t, "none")
+	defer utils.TeardownCluster(clusterInstance)
+	tablets := clusterInstance.Keyspaces[0].Shards[0].Vttablets
+
+	ctx := context.Background()
+
+	primary, replica := tablets[0], tablets[1]
+
+	// Unload semi sync plugins
+	for _, tablet := range tablets[0:4] {
+		qr := utils.RunSQL(ctx, t, "select @@global.super_read_only", tablet)
+		result := fmt.Sprintf("%v", qr.Rows[0][0].ToString())
+		if result == "1" {
+			utils.RunSQL(ctx, t, "set global super_read_only = 0", tablet)
+		}
+
+		utils.RunSQL(ctx, t, "UNINSTALL PLUGIN rpl_semi_sync_slave;", tablet)
+		utils.RunSQL(ctx, t, "UNINSTALL PLUGIN rpl_semi_sync_master;", tablet)
+	}
+
+	utils.ValidateTopology(t, clusterInstance, true)
+	utils.CheckPrimaryTablet(t, clusterInstance, primary)
+
+	// Change replica's type to rdonly
+	err := clusterInstance.VtctlclientProcess.ExecuteCommand("ChangeTabletType", replica.Alias, "rdonly")
+	require.NoError(t, err)
+
+	// Change tablets type from rdonly back to replica
+	err = clusterInstance.VtctlclientProcess.ExecuteCommand("ChangeTabletType", replica.Alias, "replica")
+	require.NoError(t, err)
+}
+
 func TestReparentDoesntHangIfPrimaryFails(t *testing.T) {
 	utilstest.SkipIfBinaryIsAboveVersion(t, 15, "vttablet")
 

go/vt/mysqlctl/fakemysqldaemon/fakemysqldaemon.go

@@ -643,6 +643,11 @@ func (fmd *FakeMysqlDaemon) SemiSyncClients() uint32 {
 	return 0
 }
 
+// SemiSyncExtensionLoaded is part of the MysqlDaemon interface.
+func (fmd *FakeMysqlDaemon) SemiSyncExtensionLoaded() bool {
+	return true
+}
+
 // SemiSyncSettings is part of the MysqlDaemon interface.
 func (fmd *FakeMysqlDaemon) SemiSyncSettings() (timeout uint64, numReplicas uint32) {
 	return 10000000, 1

go/vt/mysqlctl/mysql_daemon.go

@@ -57,6 +57,7 @@ type MysqlDaemon interface {
 	GetGTIDPurged(ctx context.Context) (mysql.Position, error)
 	SetSemiSyncEnabled(source, replica bool) error
 	SemiSyncEnabled() (source, replica bool)
+	SemiSyncExtensionLoaded() bool
 	SemiSyncStatus() (source, replica bool)
 	SemiSyncClients() (count uint32)
 	SemiSyncSettings() (timeout uint64, numReplicas uint32)

go/vt/mysqlctl/replication.go

@@ -664,3 +664,12 @@ func (mysqld *Mysqld) SemiSyncReplicationStatus() (bool, error) {
 	}
 	return false, nil
 }
+
+func (mysqld *Mysqld) SemiSyncExtensionLoaded() bool {
+	qr, err := mysqld.FetchSuperQuery(context.TODO(), "SELECT COUNT(*) > 0 AS plugin_loaded FROM information_schema.plugins WHERE plugin_name LIKE 'rpl_semi_sync%'")
+	if err != nil {
+		return false
+	}
+	pluginPresent, _ := qr.Rows[0][0].ToBool()
+	return pluginPresent
+}

go/vt/vttablet/tabletmanager/rpc_actions.go

@@ -82,7 +82,7 @@ func (tm *TabletManager) ChangeType(ctx context.Context, tabletType topodatapb.T
 		return err
 	}
 	defer tm.unlock()
-	return tm.changeTypeLocked(ctx, tabletType, DBActionNone, convertBoolToSemiSyncAction(semiSync))
+	return tm.changeTypeLocked(ctx, tabletType, DBActionNone, tm.convertBoolToSemiSyncAction(semiSync))
 }
 
 // ChangeType changes the tablet type
@@ -142,9 +142,12 @@ func (tm *TabletManager) RunHealthCheck(ctx context.Context) {
 	tm.QueryServiceControl.BroadcastHealth()
 }
 
-func convertBoolToSemiSyncAction(semiSync bool) SemiSyncAction {
+func (tm *TabletManager) convertBoolToSemiSyncAction(semiSync bool) SemiSyncAction {
 	if semiSync {
 		return SemiSyncActionSet
 	}
-	return SemiSyncActionUnset
+	if tm.MysqlDaemon.SemiSyncExtensionLoaded() {
+		return SemiSyncActionUnset
+	}
+	return SemiSyncActionNone
 }

go/vt/vttablet/tabletmanager/rpc_replication.go

@@ -294,7 +294,7 @@ func (tm *TabletManager) StartReplication(ctx context.Context, semiSync bool) er
 		}
 	}()
 
-	if err := tm.fixSemiSync(tm.Tablet().Type, convertBoolToSemiSyncAction(semiSync)); err != nil {
+	if err := tm.fixSemiSync(tm.Tablet().Type, tm.convertBoolToSemiSyncAction(semiSync)); err != nil {
 		return err
 	}
 	return tm.MysqlDaemon.StartReplication(tm.hookExtraEnv())
@@ -380,13 +380,13 @@ func (tm *TabletManager) InitPrimary(ctx context.Context, semiSync bool) (string
 	// Set the server read-write, from now on we can accept real
 	// client writes. Note that if semi-sync replication is enabled,
 	// we'll still need some replicas to be able to commit transactions.
-	if err := tm.changeTypeLocked(ctx, topodatapb.TabletType_PRIMARY, DBActionSetReadWrite, convertBoolToSemiSyncAction(semiSync)); err != nil {
+	if err := tm.changeTypeLocked(ctx, topodatapb.TabletType_PRIMARY, DBActionSetReadWrite, tm.convertBoolToSemiSyncAction(semiSync)); err != nil {
 		return "", err
 	}
 
 	// Enforce semi-sync after changing the tablet)type to PRIMARY. Otherwise, the
 	// primary will hang while trying to create the database.
-	if err := tm.fixSemiSync(topodatapb.TabletType_PRIMARY, convertBoolToSemiSyncAction(semiSync)); err != nil {
+	if err := tm.fixSemiSync(topodatapb.TabletType_PRIMARY, tm.convertBoolToSemiSyncAction(semiSync)); err != nil {
 		return "", err
 	}
 
@@ -427,7 +427,7 @@ func (tm *TabletManager) InitReplica(ctx context.Context, parent *topodatapb.Tab
 	// is used on the old primary when using InitShardPrimary with
 	// -force, and the new primary is different from the old primary.
 	if tm.Tablet().Type == topodatapb.TabletType_PRIMARY {
-		if err := tm.changeTypeLocked(ctx, topodatapb.TabletType_REPLICA, DBActionNone, convertBoolToSemiSyncAction(semiSync)); err != nil {
+		if err := tm.changeTypeLocked(ctx, topodatapb.TabletType_REPLICA, DBActionNone, tm.convertBoolToSemiSyncAction(semiSync)); err != nil {
 			return err
 		}
 	}
@@ -450,7 +450,7 @@ func (tm *TabletManager) InitReplica(ctx context.Context, parent *topodatapb.Tab
 	if tt == topodatapb.TabletType_PRIMARY {
 		tt = topodatapb.TabletType_REPLICA
 	}
-	if err := tm.fixSemiSync(tt, convertBoolToSemiSyncAction(semiSync)); err != nil {
+	if err := tm.fixSemiSync(tt, tm.convertBoolToSemiSyncAction(semiSync)); err != nil {
 		return err
 	}
 
@@ -602,7 +602,7 @@ func (tm *TabletManager) UndoDemotePrimary(ctx context.Context, semiSync bool) e
 	defer tm.unlock()
 
 	// If using semi-sync, we need to enable source-side.
-	if err := tm.fixSemiSync(topodatapb.TabletType_PRIMARY, convertBoolToSemiSyncAction(semiSync)); err != nil {
+	if err := tm.fixSemiSync(topodatapb.TabletType_PRIMARY, tm.convertBoolToSemiSyncAction(semiSync)); err != nil {
 		return err
 	}
 
@@ -672,7 +672,7 @@ func (tm *TabletManager) SetReplicationSource(ctx context.Context, parentAlias *
 
 	// setReplicationSourceLocked also fixes the semi-sync. In case the tablet type is primary it assumes that it will become a replica if SetReplicationSource
 	// is called, so we always call fixSemiSync with a non-primary tablet type. This will always set the source side replication to false.
-	return tm.setReplicationSourceLocked(ctx, parentAlias, timeCreatedNS, waitPosition, forceStartReplication, convertBoolToSemiSyncAction(semiSync))
+	return tm.setReplicationSourceLocked(ctx, parentAlias, timeCreatedNS, waitPosition, forceStartReplication, tm.convertBoolToSemiSyncAction(semiSync))
 }
 
 func (tm *TabletManager) setReplicationSourceRepairReplication(ctx context.Context, parentAlias *topodatapb.TabletAlias, timeCreatedNS int64, waitPosition string, forceStartReplication bool) (err error) {
@@ -965,7 +965,7 @@ func (tm *TabletManager) PromoteReplica(ctx context.Context, semiSync bool) (str
 	}
 
 	// If using semi-sync, we need to enable it before going read-write.
-	if err := tm.fixSemiSync(topodatapb.TabletType_PRIMARY, convertBoolToSemiSyncAction(semiSync)); err != nil {
+	if err := tm.fixSemiSync(topodatapb.TabletType_PRIMARY, tm.convertBoolToSemiSyncAction(semiSync)); err != nil {
 		return "", err
 	}
 

go/vt/vttablet/tabletmanager/tm_init.go

@@ -910,7 +910,7 @@ func (tm *TabletManager) initializeReplication(ctx context.Context, tabletType t
 	// If using semi-sync, we need to enable it before connecting to primary.
 	// We should set the correct type, since it is used in replica semi-sync
 	tablet.Type = tabletType
-	if err := tm.fixSemiSync(tabletType, convertBoolToSemiSyncAction(reparentutil.IsReplicaSemiSync(durability, currentPrimary.Tablet, tablet))); err != nil {
+	if err := tm.fixSemiSync(tabletType, tm.convertBoolToSemiSyncAction(reparentutil.IsReplicaSemiSync(durability, currentPrimary.Tablet, tablet))); err != nil {
 		return nil, err
 	}