// InitTablet creates or updates a tablet. If no parent is specified
// in the tablet, and the tablet has a slave type, we will find the
// appropriate parent. If createShardAndKeyspace is true and the
// parent keyspace or shard don't exist, they will be created. If
// allowUpdate is true, and a tablet with the same ID exists, just update it.
// If a tablet is created as master, and there is already a different
// master in the shard, allowMasterOverride must be set.
func (wr *Wrangler) InitTablet(ctx context.Context, tablet *topodatapb.Tablet, allowMasterOverride, createShardAndKeyspace, allowUpdate bool) error {
if err := topo.TabletComplete(tablet); err != nil {
return err
}
// get the shard, possibly creating it
var err error
var si *topo.ShardInfo
if createShardAndKeyspace {
// create the parent keyspace and shard if needed
si, err = wr.ts.GetOrCreateShard(ctx, tablet.Keyspace, tablet.Shard)
} else {
si, err = wr.ts.GetShard(ctx, tablet.Keyspace, tablet.Shard)
if err == topo.ErrNoNode {
return fmt.Errorf("missing parent shard, use -parent option to create it, or CreateKeyspace / CreateShard")
}
}
// get the shard, checks a couple things
if err != nil {
return fmt.Errorf("cannot get (or create) shard %v/%v: %v", tablet.Keyspace, tablet.Shard, err)
}
if !key.KeyRangeEqual(si.KeyRange, tablet.KeyRange) {
return fmt.Errorf("shard %v/%v has a different KeyRange: %v != %v", tablet.Keyspace, tablet.Shard, si.KeyRange, tablet.KeyRange)
}
if tablet.Type == topodatapb.TabletType_MASTER && si.HasMaster() && !topoproto.TabletAliasEqual(si.MasterAlias, tablet.Alias) && !allowMasterOverride {
return fmt.Errorf("creating this tablet would override old master %v in shard %v/%v, use allow_master_override flag", topoproto.TabletAliasString(si.MasterAlias), tablet.Keyspace, tablet.Shard)
}
// update the shard record if needed
if err := wr.updateShardCellsAndMaster(ctx, si, tablet.Alias, tablet.Type, allowMasterOverride); err != nil {
return err
}
err = wr.ts.CreateTablet(ctx, tablet)
if err == topo.ErrNodeExists && allowUpdate {
// Try to update then
oldTablet, err := wr.ts.GetTablet(ctx, tablet.Alias)
if err != nil {
return fmt.Errorf("failed reading existing tablet %v: %v", topoproto.TabletAliasString(tablet.Alias), err)
}
// Check we have the same keyspace / shard, and if not,
// require the allowDifferentShard flag.
if oldTablet.Keyspace != tablet.Keyspace || oldTablet.Shard != tablet.Shard {
return fmt.Errorf("old tablet has shard %v/%v. Cannot override with shard %v/%v. Delete and re-add tablet if you want to change the tablet's keyspace/shard", oldTablet.Keyspace, oldTablet.Shard, tablet.Keyspace, tablet.Shard)
}
*(oldTablet.Tablet) = *tablet
if err := wr.ts.UpdateTablet(ctx, oldTablet); err != nil {
return fmt.Errorf("failed updating tablet %v: %v", topoproto.TabletAliasString(tablet.Alias), err)
}
}
return nil
}
// updateShardCellsAndMaster will update the 'Cells' and possibly
// MasterAlias records for the shard, if needed.
func (wr *Wrangler) updateShardCellsAndMaster(ctx context.Context, si *topo.ShardInfo, tabletAlias *topodatapb.TabletAlias, tabletType topodatapb.TabletType, allowMasterOverride bool) error {
// See if we need to update the Shard:
// - add the tablet's cell to the shard's Cells if needed
// - change the master if needed
shardUpdateRequired := false
if !si.HasCell(tabletAlias.Cell) {
shardUpdateRequired = true
}
if tabletType == topodatapb.TabletType_MASTER && !topoproto.TabletAliasEqual(si.MasterAlias, tabletAlias) {
shardUpdateRequired = true
}
if !shardUpdateRequired {
return nil
}
actionNode := actionnode.UpdateShard()
keyspace := si.Keyspace()
shard := si.ShardName()
lockPath, err := wr.lockShard(ctx, keyspace, shard, actionNode)
if err != nil {
return err
}
// re-read the shard with the lock
si, err = wr.ts.GetShard(ctx, keyspace, shard)
if err != nil {
return wr.unlockShard(ctx, keyspace, shard, actionNode, lockPath, err)
}
// update it
wasUpdated := false
if !si.HasCell(tabletAlias.Cell) {
si.Cells = append(si.Cells, tabletAlias.Cell)
wasUpdated = true
}
if tabletType == topodatapb.TabletType_MASTER && !topoproto.TabletAliasEqual(si.MasterAlias, tabletAlias) {
if si.HasMaster() && !allowMasterOverride {
return wr.unlockShard(ctx, keyspace, shard, actionNode, lockPath, fmt.Errorf("creating this tablet would override old master %v in shard %v/%v", topoproto.TabletAliasString(si.MasterAlias), keyspace, shard))
}
si.MasterAlias = tabletAlias
wasUpdated = true
}
if wasUpdated {
// write it back
if err := wr.ts.UpdateShard(ctx, si); err != nil {
return wr.unlockShard(ctx, keyspace, shard, actionNode, lockPath, err)
}
}
// and unlock
return wr.unlockShard(ctx, keyspace, shard, actionNode, lockPath, err)
}
// InitTablet creates or updates a tablet. If no parent is specified
// in the tablet, and the tablet has a slave type, we will find the
// appropriate parent. If createShardAndKeyspace is true and the
// parent keyspace or shard don't exist, they will be created. If
// update is true, and a tablet with the same ID exists, update it.
// If Force is true, and a tablet with the same ID already exists, it
// will be scrapped and deleted, and then recreated.
func (wr *Wrangler) InitTablet(ctx context.Context, tablet *pb.Tablet, force, createShardAndKeyspace, update bool) error {
if err := topo.TabletComplete(tablet); err != nil {
return err
}
if topo.IsInReplicationGraph(tablet.Type) {
// get the shard, possibly creating it
var err error
var si *topo.ShardInfo
if createShardAndKeyspace {
// create the parent keyspace and shard if needed
si, err = topotools.GetOrCreateShard(ctx, wr.ts, tablet.Keyspace, tablet.Shard)
} else {
si, err = wr.ts.GetShard(ctx, tablet.Keyspace, tablet.Shard)
if err == topo.ErrNoNode {
return fmt.Errorf("missing parent shard, use -parent option to create it, or CreateKeyspace / CreateShard")
}
}
// get the shard, checks a couple things
if err != nil {
return fmt.Errorf("cannot get (or create) shard %v/%v: %v", tablet.Keyspace, tablet.Shard, err)
}
if !key.KeyRangeEqual(si.KeyRange, tablet.KeyRange) {
return fmt.Errorf("shard %v/%v has a different KeyRange: %v != %v", tablet.Keyspace, tablet.Shard, si.KeyRange, tablet.KeyRange)
}
if tablet.Type == pb.TabletType_MASTER && si.HasMaster() && !topoproto.TabletAliasEqual(si.MasterAlias, tablet.Alias) && !force {
return fmt.Errorf("creating this tablet would override old master %v in shard %v/%v", topoproto.TabletAliasString(si.MasterAlias), tablet.Keyspace, tablet.Shard)
}
// update the shard record if needed
if err := wr.updateShardCellsAndMaster(ctx, si, tablet.Alias, tablet.Type, force); err != nil {
return err
}
}
err := wr.ts.CreateTablet(ctx, tablet)
if err != nil && err == topo.ErrNodeExists {
// Try to update nicely, but if it fails fall back to force behavior.
if update || force {
oldTablet, err := wr.ts.GetTablet(ctx, tablet.Alias)
if err != nil {
wr.Logger().Warningf("failed reading tablet %v: %v", topoproto.TabletAliasString(tablet.Alias), err)
} else {
if oldTablet.Keyspace == tablet.Keyspace && oldTablet.Shard == tablet.Shard {
*(oldTablet.Tablet) = *tablet
if err := wr.ts.UpdateTablet(ctx, oldTablet); err != nil {
wr.Logger().Warningf("failed updating tablet %v: %v", topoproto.TabletAliasString(tablet.Alias), err)
// now fall through the Scrap case
} else {
if !topo.IsInReplicationGraph(tablet.Type) {
return nil
}
if err := topo.UpdateTabletReplicationData(ctx, wr.ts, tablet); err != nil {
wr.Logger().Warningf("failed updating tablet replication data for %v: %v", topoproto.TabletAliasString(tablet.Alias), err)
// now fall through the Scrap case
} else {
return nil
}
}
}
}
}
if force {
if err = wr.Scrap(ctx, tablet.Alias, force, false); err != nil {
wr.Logger().Errorf("failed scrapping tablet %v: %v", topoproto.TabletAliasString(tablet.Alias), err)
return err
}
if err := wr.ts.DeleteTablet(ctx, tablet.Alias); err != nil {
// we ignore this
wr.Logger().Errorf("failed deleting tablet %v: %v", topoproto.TabletAliasString(tablet.Alias), err)
}
return wr.ts.CreateTablet(ctx, tablet)
}
}
return err
}