Beispiel #1
0
// refreshTablet needs to be run after an action may have changed the current
// state of the tablet.
func (agent *ActionAgent) refreshTablet(ctx context.Context, reason string) error {
	log.Infof("Executing post-action state refresh")

	span := trace.NewSpanFromContext(ctx)
	span.StartLocal("ActionAgent.refreshTablet")
	span.Annotate("reason", reason)
	defer span.Finish()
	ctx = trace.NewContext(ctx, span)

	// Save the old tablet so callbacks can have a better idea of
	// the precise nature of the transition.
	oldTablet := agent.Tablet().Tablet

	// Actions should have side effects on the tablet, so reload the data.
	if err := agent.readTablet(); err != nil {
		log.Warningf("Failed rereading tablet after %v - services may be inconsistent: %v", reason, err)
		return fmt.Errorf("Failed rereading tablet after %v: %v", reason, err)
	}

	if updatedTablet := agent.checkTabletMysqlPort(agent.Tablet()); updatedTablet != nil {
		agent.mutex.Lock()
		agent._tablet = updatedTablet
		agent.mutex.Unlock()
	}

	if err := agent.updateState(ctx, oldTablet, reason); err != nil {
		return err
	}
	log.Infof("Done with post-action state refresh")
	return nil
}
Beispiel #2
0
// Update shard file with new master, replicas, etc.
//
// Re-read from TopologyServer to make sure we are using the side
// effects of all actions.
//
// This function locks individual SvrShard paths, so it doesn't need a lock
// on the shard.
func RebuildShard(ctx context.Context, log logutil.Logger, ts topo.Server, keyspace, shard string, cells []string, timeout time.Duration, interrupted chan struct{}) (*topo.ShardInfo, error) {
	log.Infof("RebuildShard %v/%v", keyspace, shard)

	span := trace.NewSpanFromContext(ctx)
	span.StartLocal("topotools.RebuildShard")
	defer span.Finish()
	ctx = trace.NewContext(ctx, span)

	// read the existing shard info. It has to exist.
	shardInfo, err := ts.GetShard(keyspace, shard)
	if err != nil {
		return nil, err
	}

	// rebuild all cells in parallel
	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	for _, cell := range shardInfo.Cells {
		// skip this cell if we shouldn't rebuild it
		if !topo.InCellList(cell, cells) {
			continue
		}

		// start with the master if it's in the current cell
		tabletsAsMap := make(map[topo.TabletAlias]bool)
		if shardInfo.MasterAlias.Cell == cell {
			tabletsAsMap[shardInfo.MasterAlias] = true
		}

		wg.Add(1)
		go func(cell string) {
			defer wg.Done()

			// Lock the SrvShard so we don't race with other rebuilds of the same
			// shard in the same cell (e.g. from our peer tablets).
			actionNode := actionnode.RebuildSrvShard()
			lockPath, err := actionNode.LockSrvShard(ctx, ts, cell, keyspace, shard, timeout, interrupted)
			if err != nil {
				rec.RecordError(err)
				return
			}

			// read the ShardReplication object to find tablets
			sri, err := ts.GetShardReplication(cell, keyspace, shard)
			if err != nil {
				rec.RecordError(fmt.Errorf("GetShardReplication(%v, %v, %v) failed: %v", cell, keyspace, shard, err))
				return
			}

			// add all relevant tablets to the map
			for _, rl := range sri.ReplicationLinks {
				tabletsAsMap[rl.TabletAlias] = true
				if rl.Parent.Cell == cell {
					tabletsAsMap[rl.Parent] = true
				}
			}

			// convert the map to a list
			aliases := make([]topo.TabletAlias, 0, len(tabletsAsMap))
			for a := range tabletsAsMap {
				aliases = append(aliases, a)
			}

			// read all the Tablet records
			tablets, err := topo.GetTabletMap(ctx, ts, aliases)
			switch err {
			case nil:
				// keep going, we're good
			case topo.ErrPartialResult:
				log.Warningf("Got ErrPartialResult from topo.GetTabletMap in cell %v, some tablets may not be added properly to serving graph", cell)
			default:
				rec.RecordError(fmt.Errorf("GetTabletMap in cell %v failed: %v", cell, err))
				return
			}

			// write the data we need to
			rebuildErr := rebuildCellSrvShard(ctx, log, ts, shardInfo, cell, tablets)

			// and unlock
			if err := actionNode.UnlockSrvShard(ctx, ts, cell, keyspace, shard, lockPath, rebuildErr); err != nil {
				rec.RecordError(err)
			}
		}(cell)
	}
	wg.Wait()

	return shardInfo, rec.Error()
}