示例#1
0
// FixShardReplication will fix the first problem it encounters within
// a ShardReplication object
func FixShardReplication(ctx context.Context, ts Server, logger logutil.Logger, cell, keyspace, shard string) error {
	sri, err := ts.GetShardReplication(ctx, cell, keyspace, shard)
	if err != nil {
		return err
	}

	for _, node := range sri.Nodes {
		ti, err := ts.GetTablet(ctx, node.TabletAlias)
		if err == ErrNoNode {
			logger.Warningf("Tablet %v is in the replication graph, but does not exist, removing it", node.TabletAlias)
			return RemoveShardReplicationRecord(ctx, ts, cell, keyspace, shard, node.TabletAlias)
		}
		if err != nil {
			// unknown error, we probably don't want to continue
			return err
		}

		if ti.Type == pb.TabletType_SCRAP {
			logger.Warningf("Tablet %v is in the replication graph, but is scrapped, removing it", node.TabletAlias)
			return RemoveShardReplicationRecord(ctx, ts, cell, keyspace, shard, node.TabletAlias)
		}

		logger.Infof("Keeping tablet %v in the replication graph", node.TabletAlias)
	}

	logger.Infof("All entries in replication graph are valid")
	return nil
}
示例#2
0
// RestartSlavesExternal will tell all the slaves in the provided list
// that they have a new master, and also tell all the masters. The
// masters will be scrapped if they don't answer.
// We execute all the actions in parallel.
func RestartSlavesExternal(ts topo.Server, log logutil.Logger, slaveTabletMap, masterTabletMap map[topo.TabletAlias]*topo.TabletInfo, masterElectTabletAlias topo.TabletAlias, slaveWasRestarted func(*topo.TabletInfo, *actionnode.SlaveWasRestartedArgs) error) {
	wg := sync.WaitGroup{}

	swrd := actionnode.SlaveWasRestartedArgs{
		Parent: masterElectTabletAlias,
	}

	log.Infof("Updating individual tablets with the right master...")

	// do all the slaves
	for _, ti := range slaveTabletMap {
		wg.Add(1)
		go func(ti *topo.TabletInfo) {
			if err := slaveWasRestarted(ti, &swrd); err != nil {
				log.Warningf("Slave %v had an error: %v", ti.Alias, err)
			}
			wg.Done()
		}(ti)
	}

	// and do the old master and any straggler, if possible.
	for _, ti := range masterTabletMap {
		wg.Add(1)
		go func(ti *topo.TabletInfo) {
			err := slaveWasRestarted(ti, &swrd)
			if err != nil {
				// the old master can be annoying if left
				// around in the replication graph, so if we
				// can't restart it, we just scrap it.
				// We don't rebuild the Shard just yet though.
				log.Warningf("Old master %v is not restarting in time, forcing it to spare: %v", ti.Alias, err)

				ti.Type = topo.TYPE_SPARE
				ti.Parent = masterElectTabletAlias
				if err := topo.UpdateTablet(ts, ti); err != nil {
					log.Warningf("Failed to change old master %v to spare: %v", ti.Alias, err)
				}
			}
			wg.Done()
		}(ti)
	}
	wg.Wait()
}
示例#3
0
// RestartSlavesExternal will tell all the slaves in the provided list
// that they have a new master, and also tell all the masters. The
// masters will be scrapped if they don't answer.
// We execute all the actions in parallel.
func RestartSlavesExternal(ts topo.Server, log logutil.Logger, slaveTabletMap, masterTabletMap map[topodatapb.TabletAlias]*topo.TabletInfo, masterElectTabletAlias *topodatapb.TabletAlias, slaveWasRestarted func(*topo.TabletInfo, *topodatapb.TabletAlias) error) {
	wg := sync.WaitGroup{}

	log.Infof("Updating individual tablets with the right master...")

	// do all the slaves
	for _, ti := range slaveTabletMap {
		wg.Add(1)
		go func(ti *topo.TabletInfo) {
			if err := slaveWasRestarted(ti, masterElectTabletAlias); err != nil {
				log.Warningf("Slave %v had an error: %v", ti.Alias, err)
			}
			wg.Done()
		}(ti)
	}

	// and do the old master and any straggler, if possible.
	for _, ti := range masterTabletMap {
		wg.Add(1)
		go func(ti *topo.TabletInfo) {
			err := slaveWasRestarted(ti, masterElectTabletAlias)
			if err != nil {
				// the old master can be annoying if left
				// around in the replication graph, so if we
				// can't restart it, we just make it spare.
				log.Warningf("Old master %v is not restarting in time, forcing it to spare: %v", ti.Alias, err)

				ti.Type = topodatapb.TabletType_SPARE
				if err := ts.UpdateTablet(context.TODO(), ti); err != nil {
					log.Warningf("Failed to change old master %v to spare: %v", ti.Alias, err)
				}
			}
			wg.Done()
		}(ti)
	}
	wg.Wait()
}
示例#4
0
// rebuildCellSrvShard computes and writes the serving graph data to a
// single cell
func rebuildCellSrvShard(ctx context.Context, log logutil.Logger, ts topo.Server, si *topo.ShardInfo, cell string) (err error) {
	log.Infof("rebuildCellSrvShard %v/%v in cell %v", si.Keyspace(), si.ShardName(), cell)

	for {
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}

		// Read existing EndPoints node versions, so we know if any
		// changes sneak in after we read the tablets.
		versions, err := getEndPointsVersions(ctx, ts, cell, si.Keyspace(), si.ShardName())

		// Get all tablets in this cell/shard.
		tablets, err := ts.GetTabletMapForShardByCell(ctx, si.Keyspace(), si.ShardName(), []string{cell})
		if err != nil {
			if err != topo.ErrPartialResult {
				return err
			}
			log.Warningf("Got ErrPartialResult from topo.GetTabletMapForShardByCell(%v), some tablets may not be added properly to serving graph", cell)
		}

		// Build up the serving graph from scratch.
		serving := make(map[pb.TabletType]*pb.EndPoints)
		for _, tablet := range tablets {
			// Only add serving types.
			if !tablet.IsInServingGraph() {
				continue
			}

			// Check the Keyspace and Shard for the tablet are right.
			if tablet.Keyspace != si.Keyspace() || tablet.Shard != si.ShardName() {
				return fmt.Errorf("CRITICAL: tablet %v is in replication graph for shard %v/%v but belongs to shard %v:%v", tablet.Alias, si.Keyspace(), si.ShardName(), tablet.Keyspace, tablet.Shard)
			}

			// Add the tablet to the list.
			endpoints, ok := serving[tablet.Type]
			if !ok {
				endpoints = topo.NewEndPoints()
				serving[tablet.Type] = endpoints
			}
			entry, err := topo.TabletEndPoint(tablet.Tablet)
			if err != nil {
				log.Warningf("EndPointForTablet failed for tablet %v: %v", tablet.Alias, err)
				continue
			}
			endpoints.Entries = append(endpoints.Entries, entry)
		}

		wg := sync.WaitGroup{}
		fatalErrs := concurrency.AllErrorRecorder{}
		retryErrs := concurrency.AllErrorRecorder{}

		// Write nodes that should exist.
		for tabletType, endpoints := range serving {
			wg.Add(1)
			go func(tabletType pb.TabletType, endpoints *pb.EndPoints) {
				defer wg.Done()

				log.Infof("saving serving graph for cell %v shard %v/%v tabletType %v", cell, si.Keyspace(), si.ShardName(), tabletType)

				version, ok := versions[tabletType]
				if !ok {
					// This type didn't exist when we first checked.
					// Try to create, but only if it still doesn't exist.
					if err := ts.CreateEndPoints(ctx, cell, si.Keyspace(), si.ShardName(), tabletType, endpoints); err != nil {
						log.Warningf("CreateEndPoints(%v, %v, %v) failed during rebuild: %v", cell, si, tabletType, err)
						switch err {
						case topo.ErrNodeExists:
							retryErrs.RecordError(err)
						default:
							fatalErrs.RecordError(err)
						}
					}
					return
				}

				// Update only if the version matches.
				if err := ts.UpdateEndPoints(ctx, cell, si.Keyspace(), si.ShardName(), tabletType, endpoints, version); err != nil {
					log.Warningf("UpdateEndPoints(%v, %v, %v) failed during rebuild: %v", cell, si, tabletType, err)
					switch err {
					case topo.ErrBadVersion, topo.ErrNoNode:
						retryErrs.RecordError(err)
					default:
						fatalErrs.RecordError(err)
					}
				}
			}(tabletType, endpoints)
		}

		// Delete nodes that shouldn't exist.
		for tabletType, version := range versions {
			if _, ok := serving[tabletType]; !ok {
				wg.Add(1)
				go func(tabletType pb.TabletType, version int64) {
					defer wg.Done()
					log.Infof("removing stale db type from serving graph: %v", tabletType)
					if err := ts.DeleteEndPoints(ctx, cell, si.Keyspace(), si.ShardName(), tabletType, version); err != nil && err != topo.ErrNoNode {
						log.Warningf("DeleteEndPoints(%v, %v, %v) failed during rebuild: %v", cell, si, tabletType, err)
						switch err {
						case topo.ErrNoNode:
							// Someone else deleted it, which is fine.
						case topo.ErrBadVersion:
							retryErrs.RecordError(err)
						default:
							fatalErrs.RecordError(err)
						}
					}
				}(tabletType, version)
			}
		}

		// Update srvShard object
		wg.Add(1)
		go func() {
			defer wg.Done()
			log.Infof("updating shard serving graph in cell %v for %v/%v", cell, si.Keyspace(), si.ShardName())
			if err := UpdateSrvShard(ctx, ts, cell, si); err != nil {
				fatalErrs.RecordError(err)
				log.Warningf("writing serving data in cell %v for %v/%v failed: %v", cell, si.Keyspace(), si.ShardName(), err)
			}
		}()

		wg.Wait()

		// If there are any fatal errors, give up.
		if fatalErrs.HasErrors() {
			return fatalErrs.Error()
		}
		// If there are any retry errors, try again.
		if retryErrs.HasErrors() {
			continue
		}
		// Otherwise, success!
		return nil
	}
}
示例#5
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(log logutil.Logger, ts topo.Server, keyspace, shard string, cells []string, timeout time.Duration, interrupted chan struct{}) error {
	log.Infof("RebuildShard %v/%v", keyspace, shard)

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

			// 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(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
			}

			// Lock the SrvShard so we write a consistent data set.
			actionNode := actionnode.RebuildSrvShard()
			lockPath, err := actionNode.LockSrvShard(ts, cell, keyspace, shard, timeout, interrupted)
			if err != nil {
				rec.RecordError(err)
				return
			}

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

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

	return rec.Error()
}
示例#6
0
// rebuildCellSrvShard computes and writes the serving graph data to a
// single cell
func rebuildCellSrvShard(log logutil.Logger, ts topo.Server, shardInfo *topo.ShardInfo, cell string, tablets map[topo.TabletAlias]*topo.TabletInfo) error {
	log.Infof("rebuildCellSrvShard %v/%v in cell %v", shardInfo.Keyspace(), shardInfo.ShardName(), cell)

	// Get all existing db types so they can be removed if nothing
	// had been edited.
	existingTabletTypes, err := ts.GetSrvTabletTypesPerShard(cell, shardInfo.Keyspace(), shardInfo.ShardName())
	if err != nil {
		if err != topo.ErrNoNode {
			return err
		}
	}

	// Update db type addresses in the serving graph
	//
	// locationAddrsMap is a map:
	//   key: tabletType
	//   value: EndPoints (list of server records)
	locationAddrsMap := make(map[topo.TabletType]*topo.EndPoints)
	for _, tablet := range tablets {
		if !tablet.IsInReplicationGraph() {
			// only valid case is a scrapped master in the
			// catastrophic reparent case
			if tablet.Parent.Uid != topo.NO_TABLET {
				log.Warningf("Tablet %v should not be in the replication graph, please investigate (it is being ignored in the rebuild)", tablet.Alias)
			}
			continue
		}

		// Check IsInServingGraph, we don't want to add tablets that
		// are not serving
		if !tablet.IsInServingGraph() {
			continue
		}

		// Check the Keyspace and Shard for the tablet are right
		if tablet.Keyspace != shardInfo.Keyspace() || tablet.Shard != shardInfo.ShardName() {
			return fmt.Errorf("CRITICAL: tablet %v is in replication graph for shard %v/%v but belongs to shard %v:%v", tablet.Alias, shardInfo.Keyspace(), shardInfo.ShardName(), tablet.Keyspace, tablet.Shard)
		}

		// Add the tablet to the list
		addrs, ok := locationAddrsMap[tablet.Type]
		if !ok {
			addrs = topo.NewEndPoints()
			locationAddrsMap[tablet.Type] = addrs
		}
		entry, err := tablet.Tablet.EndPoint()
		if err != nil {
			log.Warningf("EndPointForTablet failed for tablet %v: %v", tablet.Alias, err)
			continue
		}
		addrs.Entries = append(addrs.Entries, *entry)
	}

	// we're gonna parallelize a lot here:
	// - writing all the tabletTypes records
	// - removing the unused records
	// - writing SrvShard
	rec := concurrency.AllErrorRecorder{}
	wg := sync.WaitGroup{}

	// write all the EndPoints nodes everywhere we want them
	for tabletType, addrs := range locationAddrsMap {
		wg.Add(1)
		go func(tabletType topo.TabletType, addrs *topo.EndPoints) {
			log.Infof("saving serving graph for cell %v shard %v/%v tabletType %v", cell, shardInfo.Keyspace(), shardInfo.ShardName(), tabletType)
			if err := ts.UpdateEndPoints(cell, shardInfo.Keyspace(), shardInfo.ShardName(), tabletType, addrs); err != nil {
				rec.RecordError(fmt.Errorf("writing endpoints for cell %v shard %v/%v tabletType %v failed: %v", cell, shardInfo.Keyspace(), shardInfo.ShardName(), tabletType, err))
			}
			wg.Done()
		}(tabletType, addrs)
	}

	// Delete any pre-existing paths that were not updated by this process.
	// That's the existingTabletTypes - locationAddrsMap
	for _, tabletType := range existingTabletTypes {
		if _, ok := locationAddrsMap[tabletType]; !ok {
			wg.Add(1)
			go func(tabletType topo.TabletType) {
				log.Infof("removing stale db type from serving graph: %v", tabletType)
				if err := ts.DeleteEndPoints(cell, shardInfo.Keyspace(), shardInfo.ShardName(), tabletType); err != nil {
					log.Warningf("unable to remove stale db type %v from serving graph: %v", tabletType, err)
				}
				wg.Done()
			}(tabletType)
		}
	}

	// Update srvShard object
	wg.Add(1)
	go func() {
		log.Infof("updating shard serving graph in cell %v for %v/%v", cell, shardInfo.Keyspace(), shardInfo.ShardName())
		srvShard := &topo.SrvShard{
			Name:        shardInfo.ShardName(),
			KeyRange:    shardInfo.KeyRange,
			ServedTypes: shardInfo.ServedTypes,
			MasterCell:  shardInfo.MasterAlias.Cell,
			TabletTypes: make([]topo.TabletType, 0, len(locationAddrsMap)),
		}
		for tabletType := range locationAddrsMap {
			srvShard.TabletTypes = append(srvShard.TabletTypes, tabletType)
		}

		if err := ts.UpdateSrvShard(cell, shardInfo.Keyspace(), shardInfo.ShardName(), srvShard); err != nil {
			rec.RecordError(fmt.Errorf("writing serving data in cell %v for %v/%v failed: %v", cell, shardInfo.Keyspace(), shardInfo.ShardName(), err))
		}
		wg.Done()
	}()

	wg.Wait()
	return rec.Error()
}