Beispiel #1
0
// 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
}
Beispiel #2
0
// InitTablet initializes the tablet record if necessary.
func (agent *ActionAgent) InitTablet(port, gRPCPort int) 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 topo.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
		tabletType = topo.TabletType(*initTabletType)
		if !topo.IsTypeInList(tabletType, topo.AllTabletTypes) {
			log.Fatalf("InitTablet encountered unknown init_tablet_type '%v'", *initTabletType)
		}
		if tabletType == topo.TYPE_MASTER || tabletType == topo.TYPE_SCRAP {
			// We disallow TYPE_MASTER, so we don't have to change
			// shard.MasterAlias, and deal with the corner cases.
			// We also disallow TYPE_SCRAP, obviously.
			log.Fatalf("init_tablet_type cannot be %v", tabletType)
		}

	} else if *targetTabletType != "" {
		if tabletType := topo.TabletType(*targetTabletType); tabletType == topo.TYPE_MASTER {
			log.Fatalf("target_tablet_type cannot be '%v'. Use '%v' instead.", tabletType, topo.TYPE_REPLICA)
		}

		// use spare, the healthcheck will turn us into what
		// we need to be eventually
		tabletType = topo.TYPE_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()

	// if we're assigned to a shard, make sure it exists, see if
	// we are its master, and update its cells list if necessary
	if tabletType != topo.TYPE_IDLE {
		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 && *si.MasterAlias == *topo.TabletAliasToProto(agent.TabletAlias) {
			// we are the current master for this shard (probably
			// means the master tablet process was just restarted),
			// so InitTablet as master.
			tabletType = topo.TYPE_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 := topo.UpdateShard(ctx, agent.TopoServer, 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 == "" {
		var err error
		hostname, err = netutil.FullyQualifiedHostname()
		if err != nil {
			return err
		}
	}

	// create and populate tablet record
	tablet := &topo.Tablet{
		Alias:          agent.TabletAlias,
		Hostname:       hostname,
		Portmap:        make(map[string]int),
		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 := topo.CreateTablet(ctx, agent.TopoServer, tablet)
	switch err {
	case nil:
		// it worked, we're good, can update the replication graph
		if topo.IsInReplicationGraph(tablet.Type) {
			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 {
			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 := topo.UpdateTablet(ctx, agent.TopoServer, 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 tabletType != topo.TYPE_IDLE {
		if err := topotools.UpdateTabletEndpoints(ctx, agent.TopoServer, tablet); err != nil {
			return fmt.Errorf("UpdateTabletEndpoints failed: %v", err)
		}
	}

	return nil
}