Fixing TabletType:

- removing SNAPSHOT_SOURCE - renaming CHECKER to WORKER
2015-05-21 16:36:16 -07:00 · 2015-05-21 16:36:16 -07:00 · 7ac9766e46
--- a/go/vt/topo/tablet.go
+++ b/go/vt/topo/tablet.go
@ -164,25 +164,13 @@ const (
 	// replication sql thread may be stopped
 	TYPE_BACKUP = TabletType("backup")

-	// a slaved copy of the data, where mysqld is *not* running,
-	// and we are serving our data files to clone slaves
-	// use 'vtctl Snapshot -server-mode ...' to get in this mode
-	// use 'vtctl SnapshotSourceEnd ...' to get out of this mode
-	TYPE_SNAPSHOT_SOURCE = TabletType("snapshot_source")
-
 	// A tablet that has not been in the replication graph and is restoring
-	// from a snapshot.  idle -> restore -> spare
+	// from a snapshot.
 	TYPE_RESTORE = TabletType("restore")

-	// A tablet that is running a checker process. It is probably
+	// A tablet that is used by a worker process. It is probably
 	// lagging in replication.
-	TYPE_CHECKER = TabletType("checker")
-
-	// FIXME(szopa): Make TYPE_EXPORT a truly separate type.
-
-	// TYPE_EXPORT is tablet that is running an export process. It
-	// is probably lagging in replication.
-	TYPE_EXPORT = TYPE_CHECKER
+	TYPE_WORKER = TabletType("worker")

 	// a machine with data that needs to be wiped
 	TYPE_SCRAP = TabletType("scrap")
@ -198,9 +186,8 @@ var AllTabletTypes = []TabletType{TYPE_IDLE,
 	TYPE_EXPERIMENTAL,
 	TYPE_SCHEMA_UPGRADE,
 	TYPE_BACKUP,
-	TYPE_SNAPSHOT_SOURCE,
 	TYPE_RESTORE,
-	TYPE_CHECKER,
+	TYPE_WORKER,
 	TYPE_SCRAP,
 }

@ -213,9 +200,8 @@ var SlaveTabletTypes = []TabletType{
 	TYPE_EXPERIMENTAL,
 	TYPE_SCHEMA_UPGRADE,
 	TYPE_BACKUP,
-	TYPE_SNAPSHOT_SOURCE,
 	TYPE_RESTORE,
-	TYPE_CHECKER,
+	TYPE_WORKER,
 }

 // IsTypeInList returns true if the given type is in the list.
@ -248,9 +234,9 @@ func MakeStringTypeList(types []TabletType) []string {
 // without changes to the replication graph
 func IsTrivialTypeChange(oldTabletType, newTabletType TabletType) bool {
 	switch oldTabletType {
-	case TYPE_REPLICA, TYPE_RDONLY, TYPE_BATCH, TYPE_SPARE, TYPE_BACKUP, TYPE_SNAPSHOT_SOURCE, TYPE_EXPERIMENTAL, TYPE_SCHEMA_UPGRADE, TYPE_CHECKER:
+	case TYPE_REPLICA, TYPE_RDONLY, TYPE_BATCH, TYPE_SPARE, TYPE_BACKUP, TYPE_EXPERIMENTAL, TYPE_SCHEMA_UPGRADE, TYPE_WORKER:
 		switch newTabletType {
-		case TYPE_REPLICA, TYPE_RDONLY, TYPE_BATCH, TYPE_SPARE, TYPE_BACKUP, TYPE_SNAPSHOT_SOURCE, TYPE_EXPERIMENTAL, TYPE_SCHEMA_UPGRADE, TYPE_CHECKER:
+		case TYPE_REPLICA, TYPE_RDONLY, TYPE_BATCH, TYPE_SPARE, TYPE_BACKUP, TYPE_EXPERIMENTAL, TYPE_SCHEMA_UPGRADE, TYPE_WORKER:
 			return true
 		}
 	case TYPE_SCRAP:
@ -264,22 +250,6 @@ func IsTrivialTypeChange(oldTabletType, newTabletType TabletType) bool {
 	return false
 }

-// IsValidTypeChange returns if we should we allow this transition at
-// all.  Most transitions are allowed, but some don't make sense under
-// any circumstances. If a transition could be forced, don't disallow
-// it here.
-func IsValidTypeChange(oldTabletType, newTabletType TabletType) bool {
-	switch oldTabletType {
-	case TYPE_SNAPSHOT_SOURCE:
-		switch newTabletType {
-		case TYPE_BACKUP, TYPE_SNAPSHOT_SOURCE:
-			return false
-		}
-	}
-
-	return true
-}
-
 // IsInServingGraph returns if a tablet appears in the serving graph
 func IsInServingGraph(tt TabletType) bool {
 	switch tt {
@ -292,7 +262,7 @@ func IsInServingGraph(tt TabletType) bool {
 // IsRunningQueryService returns if a tablet is running the query service
 func IsRunningQueryService(tt TabletType) bool {
 	switch tt {
-	case TYPE_MASTER, TYPE_REPLICA, TYPE_RDONLY, TYPE_BATCH, TYPE_CHECKER:
+	case TYPE_MASTER, TYPE_REPLICA, TYPE_RDONLY, TYPE_BATCH, TYPE_WORKER:
 		return true
 	}
 	return false
@ -325,10 +295,10 @@ func IsInReplicationGraph(tt TabletType) bool {
 // and actively replicating?
 // MASTER is not obviously (only support one level replication graph)
 // IDLE and SCRAP are not either
-// BACKUP, RESTORE, TYPE_CHECKER may or may not be, but we don't know for sure
+// BACKUP, RESTORE, TYPE_WORKER may or may not be, but we don't know for sure
 func IsSlaveType(tt TabletType) bool {
 	switch tt {
-	case TYPE_MASTER, TYPE_IDLE, TYPE_SCRAP, TYPE_BACKUP, TYPE_RESTORE, TYPE_CHECKER:
+	case TYPE_MASTER, TYPE_IDLE, TYPE_SCRAP, TYPE_BACKUP, TYPE_RESTORE, TYPE_WORKER:
 		return false
 	}
 	return true
--- a/go/vt/topotools/tablet.go
+++ b/go/vt/topotools/tablet.go
@ -105,7 +105,7 @@ func ChangeType(ctx context.Context, ts topo.Server, tabletAlias topo.TabletAlia
 		return err
 	}

-	if !topo.IsTrivialTypeChange(tablet.Type, newType) || !topo.IsValidTypeChange(tablet.Type, newType) {
+	if !topo.IsTrivialTypeChange(tablet.Type, newType) {
 		return fmt.Errorf("cannot change tablet type %v -> %v %v", tablet.Type, newType, tabletAlias)
 	}

--- a/go/vt/vtctl/vtctl.go
+++ b/go/vt/vtctl/vtctl.go
@ -763,7 +763,7 @@ func commandChangeSlaveType(ctx context.Context, wr *wrangler.Wrangler, subFlags
 		if err != nil {
 			return fmt.Errorf("failed reading tablet %v: %v", tabletAlias, err)
 		}
-		if !topo.IsTrivialTypeChange(ti.Type, newType) || !topo.IsValidTypeChange(ti.Type, newType) {
+		if !topo.IsTrivialTypeChange(ti.Type, newType) {
 			return fmt.Errorf("invalid type transition %v: %v -> %v", tabletAlias, ti.Type, newType)
 		}
 		wr.Logger().Printf("- %v\n", fmtTabletAwkable(ti))
--- a/go/vt/worker/split_clone.go
+++ b/go/vt/worker/split_clone.go
@ -273,7 +273,7 @@ func (scw *SplitCloneWorker) findTargets(ctx context.Context) error {
 	// find an appropriate endpoint in the source shards
 	scw.sourceAliases = make([]topo.TabletAlias, len(scw.sourceShards))
 	for i, si := range scw.sourceShards {
-		scw.sourceAliases[i], err = FindChecker(ctx, scw.wr, scw.cleaner, scw.cell, si.Keyspace(), si.ShardName())
+		scw.sourceAliases[i], err = FindWorkerTablet(ctx, scw.wr, scw.cleaner, scw.cell, si.Keyspace(), si.ShardName())
 		if err != nil {
 			return fmt.Errorf("cannot find checker for %v/%v/%v: %v", scw.cell, si.Keyspace(), si.ShardName(), err)
 		}
--- a/go/vt/worker/split_diff.go
+++ b/go/vt/worker/split_diff.go
@ -180,7 +180,7 @@ func (sdw *SplitDiffWorker) findTargets(ctx context.Context) error {

 	// find an appropriate endpoint in destination shard
 	var err error
-	sdw.destinationAlias, err = FindChecker(ctx, sdw.wr, sdw.cleaner, sdw.cell, sdw.keyspace, sdw.shard)
+	sdw.destinationAlias, err = FindWorkerTablet(ctx, sdw.wr, sdw.cleaner, sdw.cell, sdw.keyspace, sdw.shard)
 	if err != nil {
 		return fmt.Errorf("cannot find checker for %v/%v/%v: %v", sdw.cell, sdw.keyspace, sdw.shard, err)
 	}
@ -188,7 +188,7 @@ func (sdw *SplitDiffWorker) findTargets(ctx context.Context) error {
 	// find an appropriate endpoint in the source shards
 	sdw.sourceAliases = make([]topo.TabletAlias, len(sdw.shardInfo.SourceShards))
 	for i, ss := range sdw.shardInfo.SourceShards {
-		sdw.sourceAliases[i], err = FindChecker(ctx, sdw.wr, sdw.cleaner, sdw.cell, sdw.keyspace, ss.Shard)
+		sdw.sourceAliases[i], err = FindWorkerTablet(ctx, sdw.wr, sdw.cleaner, sdw.cell, sdw.keyspace, ss.Shard)
 		if err != nil {
 			return fmt.Errorf("cannot find checker for %v/%v/%v: %v", sdw.cell, sdw.keyspace, ss.Shard, err)
 		}
--- a/go/vt/worker/sqldiffer.go
+++ b/go/vt/worker/sqldiffer.go
@ -146,13 +146,13 @@ func (worker *SQLDiffWorker) findTargets(ctx context.Context) error {

 	// find an appropriate endpoint in superset
 	var err error
-	worker.superset.alias, err = FindChecker(ctx, worker.wr, worker.cleaner, worker.cell, worker.superset.Keyspace, worker.superset.Shard)
+	worker.superset.alias, err = FindWorkerTablet(ctx, worker.wr, worker.cleaner, worker.cell, worker.superset.Keyspace, worker.superset.Shard)
 	if err != nil {
 		return err
 	}

 	// find an appropriate endpoint in subset
-	worker.subset.alias, err = FindChecker(ctx, worker.wr, worker.cleaner, worker.cell, worker.subset.Keyspace, worker.subset.Shard)
+	worker.subset.alias, err = FindWorkerTablet(ctx, worker.wr, worker.cleaner, worker.cell, worker.subset.Keyspace, worker.subset.Shard)
 	if err != nil {
 		return err
 	}
--- a/go/vt/worker/topo_utils.go
+++ b/go/vt/worker/topo_utils.go
@ -46,11 +46,11 @@ func FindHealthyRdonlyEndPoint(wr *wrangler.Wrangler, cell, keyspace, shard stri
 	}, nil
 }

-// FindChecker will:
+// FindWorkerTablet will:
 // - find a rdonly instance in the keyspace / shard
-// - mark it as checker
+// - mark it as worker
 // - tag it with our worker process
-func FindChecker(ctx context.Context, wr *wrangler.Wrangler, cleaner *wrangler.Cleaner, cell, keyspace, shard string) (topo.TabletAlias, error) {
+func FindWorkerTablet(ctx context.Context, wr *wrangler.Wrangler, cleaner *wrangler.Cleaner, cell, keyspace, shard string) (topo.TabletAlias, error) {
 	tabletAlias, err := FindHealthyRdonlyEndPoint(wr, cell, keyspace, shard)
 	if err != nil {
 		return topo.TabletAlias{}, err
@ -76,7 +76,7 @@ func FindChecker(ctx context.Context, wr *wrangler.Wrangler, cleaner *wrangler.C

 	wr.Logger().Infof("Changing tablet %v to 'checker'", tabletAlias)
 	shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
-	err = wr.ChangeType(shortCtx, tabletAlias, topo.TYPE_CHECKER, false /*force*/)
+	err = wr.ChangeType(shortCtx, tabletAlias, topo.TYPE_WORKER, false /*force*/)
 	cancel()
 	if err != nil {
 		return topo.TabletAlias{}, err
--- a/go/vt/worker/vertical_split_clone.go
+++ b/go/vt/worker/vertical_split_clone.go
@ -243,7 +243,7 @@ func (vscw *VerticalSplitCloneWorker) findTargets(ctx context.Context) error {

 	// find an appropriate endpoint in the source shard
 	var err error
-	vscw.sourceAlias, err = FindChecker(ctx, vscw.wr, vscw.cleaner, vscw.cell, vscw.sourceKeyspace, "0")
+	vscw.sourceAlias, err = FindWorkerTablet(ctx, vscw.wr, vscw.cleaner, vscw.cell, vscw.sourceKeyspace, "0")
 	if err != nil {
 		return fmt.Errorf("cannot find checker for %v/%v/0: %v", vscw.cell, vscw.sourceKeyspace, err)
 	}
--- a/go/vt/worker/vertical_split_diff.go
+++ b/go/vt/worker/vertical_split_diff.go
@ -189,13 +189,13 @@ func (vsdw *VerticalSplitDiffWorker) findTargets(ctx context.Context) error {

 	// find an appropriate endpoint in destination shard
 	var err error
-	vsdw.destinationAlias, err = FindChecker(ctx, vsdw.wr, vsdw.cleaner, vsdw.cell, vsdw.keyspace, vsdw.shard)
+	vsdw.destinationAlias, err = FindWorkerTablet(ctx, vsdw.wr, vsdw.cleaner, vsdw.cell, vsdw.keyspace, vsdw.shard)
 	if err != nil {
 		return fmt.Errorf("cannot find checker for %v/%v/%v: %v", vsdw.cell, vsdw.keyspace, vsdw.shard, err)
 	}

 	// find an appropriate endpoint in the source shard
-	vsdw.sourceAlias, err = FindChecker(ctx, vsdw.wr, vsdw.cleaner, vsdw.cell, vsdw.shardInfo.SourceShards[0].Keyspace, vsdw.shardInfo.SourceShards[0].Shard)
+	vsdw.sourceAlias, err = FindWorkerTablet(ctx, vsdw.wr, vsdw.cleaner, vsdw.cell, vsdw.shardInfo.SourceShards[0].Keyspace, vsdw.shardInfo.SourceShards[0].Shard)
 	if err != nil {
 		return fmt.Errorf("cannot find checker for %v/%v/%v: %v", vsdw.cell, vsdw.shardInfo.SourceShards[0].Keyspace, vsdw.shardInfo.SourceShards[0].Shard, err)
 	}