// updateReplicationGraphForPromotedSlave makes sure the newly promoted slave
// is correctly represented in the replication graph
func (agent *ActionAgent) updateReplicationGraphForPromotedSlave(tablet *topo.TabletInfo) error {
// Update tablet regardless - trend towards consistency.
tablet.State = topo.STATE_READ_WRITE
tablet.Type = topo.TYPE_MASTER
tablet.Parent.Cell = ""
tablet.Parent.Uid = topo.NO_TABLET
tablet.Health = nil
err := topo.UpdateTablet(agent.TopoServer, tablet)
if err != nil {
return err
}
// NOTE(msolomon) A serving graph update is required, but in
// order for the shard to be consistent the old master must be
// scrapped first. That is externally coordinated by the
// wrangler reparent action.
// Insert the new tablet location in the replication graph now that
// we've updated the tablet.
err = topo.UpdateTabletReplicationData(agent.TopoServer, tablet.Tablet)
if err != nil && err != topo.ErrNodeExists {
return err
}
return nil
}
// SlaveWasRestarted updates the parent record for a tablet.
// Should be called under RpcWrapLockAction.
func (agent *ActionAgent) SlaveWasRestarted(swrd *actionnode.SlaveWasRestartedArgs) error {
tablet, err := agent.TopoServer.GetTablet(agent.TabletAlias)
if err != nil {
return err
}
// Once this action completes, update authoritive tablet node first.
tablet.Parent = swrd.Parent
if tablet.Type == topo.TYPE_MASTER {
tablet.Type = topo.TYPE_SPARE
tablet.State = topo.STATE_READ_ONLY
}
err = topo.UpdateTablet(agent.TopoServer, tablet)
if err != nil {
return err
}
// Update the new tablet location in the replication graph now that
// we've updated the tablet.
err = topo.UpdateTabletReplicationData(agent.TopoServer, tablet.Tablet)
if err != nil && err != topo.ErrNodeExists {
return err
}
return nil
}
// updateReplicationGraphForPromotedSlave makes sure the newly promoted slave
// is correctly represented in the replication graph
func (agent *ActionAgent) updateReplicationGraphForPromotedSlave(ctx context.Context, tablet *topo.TabletInfo) error {
// Update tablet regardless - trend towards consistency.
tablet.Type = pb.TabletType_MASTER
tablet.HealthMap = nil
err := agent.TopoServer.UpdateTablet(ctx, tablet)
if err != nil {
return err
}
// NOTE(msolomon) A serving graph update is required, but in
// order for the shard to be consistent the old master must be
// dealt with first. That is externally coordinated by the
// wrangler reparent action.
// Insert the new tablet location in the replication graph now that
// we've updated the tablet.
err = topo.UpdateTabletReplicationData(ctx, agent.TopoServer, tablet.Tablet)
if err != nil && err != topo.ErrNodeExists {
return err
}
return nil
}
// change a tablet type to RESTORE and set all the other arguments.
// from now on, we can go to:
// - back to IDLE if we don't use the tablet at all (after for instance
// a successful ReserveForRestore but a failed Snapshot)
// - to SCRAP if something in the process on the target host fails
// - to SPARE if the clone works
func (agent *ActionAgent) changeTypeToRestore(tablet, sourceTablet *topo.TabletInfo, parentAlias topo.TabletAlias, keyRange key.KeyRange) error {
// run the optional preflight_assigned hook
hk := hook.NewSimpleHook("preflight_assigned")
topotools.ConfigureTabletHook(hk, agent.TabletAlias)
if err := hk.ExecuteOptional(); err != nil {
return err
}
// change the type
tablet.Parent = parentAlias
tablet.Keyspace = sourceTablet.Keyspace
tablet.Shard = sourceTablet.Shard
tablet.Type = topo.TYPE_RESTORE
tablet.KeyRange = keyRange
tablet.DbNameOverride = sourceTablet.DbNameOverride
if err := topo.UpdateTablet(agent.TopoServer, tablet); err != nil {
return err
}
// and create the replication graph items
return topo.UpdateTabletReplicationData(agent.TopoServer, tablet.Tablet)
}
// SlaveWasRestarted updates the parent record for a tablet.
// Should be called under RPCWrapLockAction.
func (agent *ActionAgent) SlaveWasRestarted(ctx context.Context, swrd *actionnode.SlaveWasRestartedArgs) error {
tablet, err := agent.TopoServer.GetTablet(ctx, agent.TabletAlias)
if err != nil {
return err
}
// Once this action completes, update authoritative tablet node first.
if tablet.Type == pb.TabletType_MASTER {
tablet.Type = pb.TabletType_SPARE
}
err = agent.TopoServer.UpdateTablet(ctx, tablet)
if err != nil {
return err
}
// Update the new tablet location in the replication graph now that
// we've updated the tablet.
err = topo.UpdateTabletReplicationData(ctx, agent.TopoServer, tablet.Tablet)
if err != nil && err != topo.ErrNodeExists {
return err
}
return nil
}
// InitTablet initializes the tablet record if necessary.
func (agent *ActionAgent) InitTablet(port, gRPCPort int32) error {
// only enabled if one of init_tablet_type (when healthcheck
// is disabled) or init_keyspace (when healthcheck is enabled)
// is passed in, then check other parameters
if *initTabletType == "" && *initKeyspace == "" {
return nil
}
// figure out our default target type
var tabletType topodatapb.TabletType
if *initTabletType != "" {
if *targetTabletType != "" {
log.Fatalf("cannot specify both target_tablet_type and init_tablet_type parameters (as they might conflict)")
}
// use the type specified on the command line
var err error
tabletType, err = topoproto.ParseTabletType(*initTabletType)
if err != nil {
log.Fatalf("Invalid init tablet type %v: %v", *initTabletType, err)
}
if tabletType == topodatapb.TabletType_MASTER {
// We disallow MASTER, so we don't have to change
// shard.MasterAlias, and deal with the corner cases.
log.Fatalf("init_tablet_type cannot be %v", tabletType)
}
} else if *targetTabletType != "" {
if strings.ToUpper(*targetTabletType) == topodatapb.TabletType_name[int32(topodatapb.TabletType_MASTER)] {
log.Fatalf("target_tablet_type cannot be '%v'. Use '%v' instead.", tabletType, topodatapb.TabletType_REPLICA)
}
// use spare, the healthcheck will turn us into what
// we need to be eventually
tabletType = topodatapb.TabletType_SPARE
} else {
log.Fatalf("if init tablet is enabled, one of init_tablet_type or target_tablet_type needs to be specified")
}
// create a context for this whole operation
ctx, cancel := context.WithTimeout(agent.batchCtx, *initTimeout)
defer cancel()
// since we're assigned to a shard, make sure it exists, see if
// we are its master, and update its cells list if necessary
if *initKeyspace == "" || *initShard == "" {
log.Fatalf("if init tablet is enabled and the target type is not idle, init_keyspace and init_shard also need to be specified")
}
shard, _, err := topo.ValidateShardName(*initShard)
if err != nil {
log.Fatalf("cannot validate shard name: %v", err)
}
log.Infof("Reading shard record %v/%v", *initKeyspace, shard)
// read the shard, create it if necessary
si, err := topotools.GetOrCreateShard(ctx, agent.TopoServer, *initKeyspace, shard)
if err != nil {
return fmt.Errorf("InitTablet cannot GetOrCreateShard shard: %v", err)
}
if si.MasterAlias != nil && topoproto.TabletAliasEqual(si.MasterAlias, agent.TabletAlias) {
// we are the current master for this shard (probably
// means the master tablet process was just restarted),
// so InitTablet as master.
tabletType = topodatapb.TabletType_MASTER
}
// See if we need to add the tablet's cell to the shard's cell
// list. If we do, it has to be under the shard lock.
if !si.HasCell(agent.TabletAlias.Cell) {
actionNode := actionnode.UpdateShard()
lockPath, err := actionNode.LockShard(ctx, agent.TopoServer, *initKeyspace, shard)
if err != nil {
return fmt.Errorf("LockShard(%v/%v) failed: %v", *initKeyspace, shard, err)
}
// re-read the shard with the lock
si, err = agent.TopoServer.GetShard(ctx, *initKeyspace, shard)
if err != nil {
return actionNode.UnlockShard(ctx, agent.TopoServer, *initKeyspace, shard, lockPath, err)
}
// see if we really need to update it now
if !si.HasCell(agent.TabletAlias.Cell) {
si.Cells = append(si.Cells, agent.TabletAlias.Cell)
// write it back
if err := agent.TopoServer.UpdateShard(ctx, si); err != nil {
return actionNode.UnlockShard(ctx, agent.TopoServer, *initKeyspace, shard, lockPath, err)
}
}
// and unlock
if err := actionNode.UnlockShard(ctx, agent.TopoServer, *initKeyspace, shard, lockPath, nil); err != nil {
return err
}
}
log.Infof("Initializing the tablet for type %v", tabletType)
// figure out the hostname
hostname := *tabletHostname
if hostname != "" {
log.Infof("Using hostname: %v from -tablet_hostname flag.", hostname)
} else {
hostname, err := netutil.FullyQualifiedHostname()
if err != nil {
return err
}
log.Infof("Using detected machine hostname: %v To change this, fix your machine network configuration or override it with -tablet_hostname.", hostname)
}
// create and populate tablet record
tablet := &topodatapb.Tablet{
Alias: agent.TabletAlias,
Hostname: hostname,
PortMap: make(map[string]int32),
Keyspace: *initKeyspace,
Shard: *initShard,
Type: tabletType,
DbNameOverride: *initDbNameOverride,
Tags: initTags,
}
if port != 0 {
tablet.PortMap["vt"] = port
}
if gRPCPort != 0 {
tablet.PortMap["grpc"] = gRPCPort
}
if err := topo.TabletComplete(tablet); err != nil {
return fmt.Errorf("InitTablet TabletComplete failed: %v", err)
}
// now try to create the record
err = agent.TopoServer.CreateTablet(ctx, tablet)
switch err {
case nil:
// it worked, we're good, can update the replication graph
if err := topo.UpdateTabletReplicationData(ctx, agent.TopoServer, tablet); err != nil {
return fmt.Errorf("UpdateTabletReplicationData failed: %v", err)
}
case topo.ErrNodeExists:
// The node already exists, will just try to update
// it. So we read it first.
oldTablet, err := agent.TopoServer.GetTablet(ctx, tablet.Alias)
if err != nil {
return fmt.Errorf("InitTablet failed to read existing tablet record: %v", err)
}
// Sanity check the keyspace and shard
if oldTablet.Keyspace != tablet.Keyspace || oldTablet.Shard != tablet.Shard {
return fmt.Errorf("InitTablet failed because existing tablet keyspace and shard %v/%v differ from the provided ones %v/%v", oldTablet.Keyspace, oldTablet.Shard, tablet.Keyspace, tablet.Shard)
}
// And overwrite the rest
*(oldTablet.Tablet) = *tablet
if err := agent.TopoServer.UpdateTablet(ctx, oldTablet); err != nil {
return fmt.Errorf("UpdateTablet failed: %v", err)
}
// Note we don't need to UpdateTabletReplicationData
// as the tablet already existed with the right data
// in the replication graph
default:
return fmt.Errorf("CreateTablet failed: %v", err)
}
// and now update the serving graph. Note we do that in any case,
// to clean any inaccurate record from any part of the serving graph.
if err := topotools.UpdateTabletEndpoints(ctx, agent.TopoServer, tablet); err != nil {
return fmt.Errorf("UpdateTabletEndpoints failed: %v", err)
}
return nil
}
// 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 *topo.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.ProtoToKeyRange(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 == topo.TYPE_MASTER && !topo.TabletAliasIsZero(si.MasterAlias) && topo.ProtoToTabletAlias(si.MasterAlias) != tablet.Alias && !force {
return fmt.Errorf("creating this tablet would override old master %v in shard %v/%v", si.MasterAlias, tablet.Keyspace, tablet.Shard)
}
// update the shard record if needed
if err := wr.updateShardCellsAndMaster(ctx, si, topo.TabletAliasToProto(tablet.Alias), topo.TabletTypeToProto(tablet.Type), force); err != nil {
return err
}
}
err := topo.CreateTablet(ctx, wr.ts, 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", tablet.Alias, err)
} else {
if oldTablet.Keyspace == tablet.Keyspace && oldTablet.Shard == tablet.Shard {
*(oldTablet.Tablet) = *tablet
if err := topo.UpdateTablet(ctx, wr.ts, oldTablet); err != nil {
wr.Logger().Warningf("failed updating tablet %v: %v", 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", 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", 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", tablet.Alias, err)
}
return topo.CreateTablet(ctx, wr.ts, tablet)
}
}
return 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(tablet *topo.Tablet, force, createShardAndKeyspace, update bool) error {
if err := tablet.Complete(); err != nil {
return err
}
if tablet.IsInReplicationGraph() {
// create the parent keyspace and shard if needed
if createShardAndKeyspace {
if err := wr.ts.CreateKeyspace(tablet.Keyspace, &topo.Keyspace{}); err != nil && err != topo.ErrNodeExists {
return err
}
if err := topo.CreateShard(wr.ts, tablet.Keyspace, tablet.Shard); err != nil && err != topo.ErrNodeExists {
return err
}
}
// get the shard, checks a couple things
si, err := wr.ts.GetShard(tablet.Keyspace, tablet.Shard)
if err != nil {
return fmt.Errorf("missing parent shard, use -parent option to create it, or CreateKeyspace / CreateShard")
}
if 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 == topo.TYPE_MASTER && !si.MasterAlias.IsZero() && si.MasterAlias != tablet.Alias && !force {
return fmt.Errorf("creating this tablet would override old master %v in shard %v/%v", si.MasterAlias, tablet.Keyspace, tablet.Shard)
}
// see if we specified a parent, otherwise get it from the shard
if tablet.Parent.IsZero() && tablet.Type.IsSlaveType() {
if si.MasterAlias.IsZero() {
return fmt.Errorf("trying to create tablet %v in shard %v/%v without a master", tablet.Alias, tablet.Keyspace, tablet.Shard)
}
tablet.Parent = si.MasterAlias
}
// update the shard record if needed
if err := wr.updateShardCellsAndMaster(si, tablet.Alias, tablet.Type, force); err != nil {
return err
}
}
err := topo.CreateTablet(wr.ts, 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(tablet.Alias)
if err != nil {
log.Warningf("failed reading tablet %v: %v", tablet.Alias, err)
} else {
if oldTablet.Keyspace == tablet.Keyspace && oldTablet.Shard == tablet.Shard {
*(oldTablet.Tablet) = *tablet
if err := topo.UpdateTablet(wr.ts, oldTablet); err != nil {
log.Warningf("failed updating tablet %v: %v", tablet.Alias, err)
// now fall through the Scrap case
} else {
if !tablet.IsInReplicationGraph() {
return nil
}
if err := topo.UpdateTabletReplicationData(wr.ts, tablet); err != nil {
log.Warningf("failed updating tablet replication data for %v: %v", tablet.Alias, err)
// now fall through the Scrap case
} else {
return nil
}
}
}
}
}
if force {
if err = wr.Scrap(tablet.Alias, force, false); err != nil {
log.Errorf("failed scrapping tablet %v: %v", tablet.Alias, err)
return err
}
if err := wr.ts.DeleteTablet(tablet.Alias); err != nil {
// we ignore this
log.Errorf("failed deleting tablet %v: %v", tablet.Alias, err)
}
return topo.CreateTablet(wr.ts, tablet)
}
}
return err
}
// RebuildReplicationGraph is a quick and dirty tool to resurrect the TopologyServer data from the
// canonical data stored in the tablet nodes.
//
// cells: local vt cells to scan for all tablets
// keyspaces: list of keyspaces to rebuild
func (wr *Wrangler) RebuildReplicationGraph(ctx context.Context, cells []string, keyspaces []string) error {
if cells == nil || len(cells) == 0 {
return fmt.Errorf("must specify cells to rebuild replication graph")
}
if keyspaces == nil || len(keyspaces) == 0 {
return fmt.Errorf("must specify keyspaces to rebuild replication graph")
}
allTablets := make([]*topo.TabletInfo, 0, 1024)
for _, cell := range cells {
tablets, err := topotools.GetAllTablets(ctx, wr.ts, cell)
if err != nil {
return err
}
allTablets = append(allTablets, tablets...)
}
for _, keyspace := range keyspaces {
wr.logger.Infof("delete keyspace shards: %v", keyspace)
if err := wr.ts.DeleteKeyspaceShards(ctx, keyspace); err != nil {
return err
}
}
keyspacesToRebuild := make(map[string]bool)
shardsCreated := make(map[string]bool)
hasErr := false
mu := sync.Mutex{}
wg := sync.WaitGroup{}
for _, ti := range allTablets {
wg.Add(1)
go func(ti *topo.TabletInfo) {
defer wg.Done()
if !strInList(keyspaces, ti.Keyspace) {
return
}
mu.Lock()
keyspacesToRebuild[ti.Keyspace] = true
shardPath := ti.Keyspace + "/" + ti.Shard
if !shardsCreated[shardPath] {
if err := wr.ts.CreateShard(ctx, ti.Keyspace, ti.Shard); err != nil && err != topo.ErrNodeExists {
wr.logger.Warningf("failed re-creating shard %v: %v", shardPath, err)
hasErr = true
} else {
shardsCreated[shardPath] = true
}
}
mu.Unlock()
err := topo.UpdateTabletReplicationData(ctx, wr.ts, ti.Tablet)
if err != nil {
mu.Lock()
hasErr = true
mu.Unlock()
wr.logger.Warningf("failed updating replication data: %v", err)
}
}(ti)
}
wg.Wait()
for keyspace := range keyspacesToRebuild {
wg.Add(1)
go func(keyspace string) {
defer wg.Done()
if err := wr.RebuildKeyspaceGraph(ctx, keyspace, nil); err != nil {
mu.Lock()
hasErr = true
mu.Unlock()
wr.logger.Warningf("RebuildKeyspaceGraph(%v) failed: %v", keyspace, err)
return
}
}(keyspace)
}
wg.Wait()
if hasErr {
return fmt.Errorf("some errors occurred rebuilding replication graph, consult log")
}
return nil
}
// 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 already exists, and has a different keyspace / shard,
// allowDifferentShard must be set to accept the update.
// 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, allowDifferentShard, 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 = 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 == 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) && !allowDifferentShard {
return fmt.Errorf("old tablet has shard %v/%v, cannot override with shard %v/%v unless allow_different_shard is set", 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)
}
}
// now update the replication data
if err := topo.UpdateTabletReplicationData(ctx, wr.ts, tablet); err != nil {
return fmt.Errorf("failed updating tablet replication data for %v: %v", topoproto.TabletAliasString(tablet.Alias), err)
}
return nil
}
// RestartSlave tells the tablet it has a new master
// Should be called under RpcWrapLockAction.
func (agent *ActionAgent) RestartSlave(rsd *actionnode.RestartSlaveData) error {
tablet, err := agent.TopoServer.GetTablet(agent.TabletAlias)
if err != nil {
return err
}
// If this check fails, we seem reparented. The only part that
// could have failed is the insert in the replication
// graph. Do NOT try to reparent again. That will either wedge
// replication or corrupt data.
if tablet.Parent != rsd.Parent {
log.V(6).Infof("restart with new parent")
// Remove tablet from the replication graph.
if err = topo.DeleteTabletReplicationData(agent.TopoServer, tablet.Tablet); err != nil && err != topo.ErrNoNode {
return err
}
// Move a lag slave into the orphan lag type so we can safely ignore
// this reparenting until replication catches up.
if tablet.Type == topo.TYPE_LAG {
tablet.Type = topo.TYPE_LAG_ORPHAN
} else {
err = agent.Mysqld.RestartSlave(rsd.ReplicationStatus, rsd.WaitPosition, rsd.TimePromoted)
if err != nil {
return err
}
}
// Once this action completes, update authoritive tablet node first.
tablet.Parent = rsd.Parent
err = topo.UpdateTablet(agent.TopoServer, tablet)
if err != nil {
return err
}
} else if rsd.Force {
err = agent.Mysqld.RestartSlave(rsd.ReplicationStatus, rsd.WaitPosition, rsd.TimePromoted)
if err != nil {
return err
}
// Complete the special orphan accounting.
if tablet.Type == topo.TYPE_LAG_ORPHAN {
tablet.Type = topo.TYPE_LAG
err = topo.UpdateTablet(agent.TopoServer, tablet)
if err != nil {
return err
}
}
} else {
// There is nothing to safely reparent, so check replication. If
// either replication thread is not running, report an error.
status, err := agent.Mysqld.SlaveStatus()
if err != nil {
return fmt.Errorf("cannot verify replication for slave: %v", err)
}
if !status.SlaveRunning() {
return fmt.Errorf("replication not running for slave")
}
}
// Insert the new tablet location in the replication graph now that
// we've updated the tablet.
err = topo.UpdateTabletReplicationData(agent.TopoServer, tablet.Tablet)
if err != nil && err != topo.ErrNodeExists {
return err
}
return nil
}
// InitTablet initializes the tablet record if necessary.
func (agent *ActionAgent) InitTablet(port, gRPCPort int32) error {
// it should be either we have all three of init_keyspace,
// init_shard and init_tablet_type, or none.
if *initKeyspace == "" && *initShard == "" && *initTabletType == "" {
// not initializing the record
return nil
}
if *initKeyspace == "" || *initShard == "" || *initTabletType == "" {
return fmt.Errorf("either need all of init_keyspace, init_shard and init_tablet_type, or none")
}
// parse init_tablet_type
tabletType, err := topoproto.ParseTabletType(*initTabletType)
if err != nil {
return fmt.Errorf("invalid init_tablet_type %v: %v", *initTabletType, err)
}
if tabletType == topodatapb.TabletType_MASTER {
// We disallow MASTER, so we don't have to change
// shard.MasterAlias, and deal with the corner cases.
return fmt.Errorf("init_tablet_type cannot be master, use replica instead")
}
// parse and validate shard name
shard, _, err := topo.ValidateShardName(*initShard)
if err != nil {
return fmt.Errorf("cannot validate shard name %v: %v", *initShard, err)
}
// create a context for this whole operation
ctx, cancel := context.WithTimeout(agent.batchCtx, *initTimeout)
defer cancel()
// read the shard, create it if necessary
log.Infof("Reading shard record %v/%v", *initKeyspace, shard)
si, err := agent.TopoServer.GetOrCreateShard(ctx, *initKeyspace, shard)
if err != nil {
return fmt.Errorf("InitTablet cannot GetOrCreateShard shard: %v", err)
}
if si.MasterAlias != nil && topoproto.TabletAliasEqual(si.MasterAlias, agent.TabletAlias) {
// We're marked as master in the shard record, which could mean the master
// tablet process was just restarted. However, we need to check if a new
// master is in the process of taking over. In that case, it will let us
// know by forcibly updating the old master's tablet record.
oldTablet, err := agent.TopoServer.GetTablet(ctx, agent.TabletAlias)
switch err {
case topo.ErrNoNode:
// There's no existing tablet record, so we can assume
// no one has left us a message to step down.
tabletType = topodatapb.TabletType_MASTER
case nil:
if oldTablet.Type == topodatapb.TabletType_MASTER {
// We're marked as master in the shard record,
// and our existing tablet record agrees.
tabletType = topodatapb.TabletType_MASTER
}
default:
return fmt.Errorf("InitTablet failed to read existing tablet record: %v", err)
}
}
// See if we need to add the tablet's cell to the shard's cell list.
if !si.HasCell(agent.TabletAlias.Cell) {
si, err = agent.TopoServer.UpdateShardFields(ctx, *initKeyspace, shard, func(si *topo.ShardInfo) error {
if si.HasCell(agent.TabletAlias.Cell) {
// Someone else already did it.
return topo.ErrNoUpdateNeeded
}
si.Cells = append(si.Cells, agent.TabletAlias.Cell)
return nil
})
if err != nil {
return fmt.Errorf("couldn't add tablet's cell to shard record: %v", err)
}
}
log.Infof("Initializing the tablet for type %v", tabletType)
// figure out the hostname
hostname := *tabletHostname
if hostname != "" {
log.Infof("Using hostname: %v from -tablet_hostname flag.", hostname)
} else {
hostname, err := netutil.FullyQualifiedHostname()
if err != nil {
return err
}
log.Infof("Using detected machine hostname: %v To change this, fix your machine network configuration or override it with -tablet_hostname.", hostname)
}
// create and populate tablet record
tablet := &topodatapb.Tablet{
Alias: agent.TabletAlias,
Hostname: hostname,
PortMap: make(map[string]int32),
Keyspace: *initKeyspace,
Shard: *initShard,
Type: tabletType,
DbNameOverride: *initDbNameOverride,
Tags: initTags,
}
if port != 0 {
tablet.PortMap["vt"] = port
}
if gRPCPort != 0 {
tablet.PortMap["grpc"] = gRPCPort
}
if err := topo.TabletComplete(tablet); err != nil {
return fmt.Errorf("InitTablet TabletComplete failed: %v", err)
}
// now try to create the record
err = agent.TopoServer.CreateTablet(ctx, tablet)
switch err {
case nil:
// it worked, we're good, can update the replication graph
if err := topo.UpdateTabletReplicationData(ctx, agent.TopoServer, tablet); err != nil {
return fmt.Errorf("UpdateTabletReplicationData failed: %v", err)
}
case topo.ErrNodeExists:
// The node already exists, will just try to update it. So we read it first.
oldTablet, err := agent.TopoServer.GetTablet(ctx, tablet.Alias)
if err != nil {
return fmt.Errorf("InitTablet failed to read existing tablet record: %v", err)
}
// Sanity check the keyspace and shard
if oldTablet.Keyspace != tablet.Keyspace || oldTablet.Shard != tablet.Shard {
return fmt.Errorf("InitTablet failed because existing tablet keyspace and shard %v/%v differ from the provided ones %v/%v", oldTablet.Keyspace, oldTablet.Shard, tablet.Keyspace, tablet.Shard)
}
// Then overwrite everything, ignoring version mismatch.
if err := agent.TopoServer.UpdateTablet(ctx, topo.NewTabletInfo(tablet, -1)); err != nil {
return fmt.Errorf("UpdateTablet failed: %v", err)
}
// Note we don't need to UpdateTabletReplicationData
// as the tablet already existed with the right data
// in the replication graph
default:
return fmt.Errorf("CreateTablet failed: %v", err)
}
return nil
}
