Golang AllErrorRecorder.HasErrors方法代碼示例

// CopyKeyspaces will create the keyspaces in the destination topo
func CopyKeyspaces(fromTS, toTS topo.Server) {
	keyspaces, err := fromTS.GetKeyspaces()
	if err != nil {
		log.Fatalf("GetKeyspaces: %v", err)
	}

	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	for _, keyspace := range keyspaces {
		wg.Add(1)
		go func(keyspace string) {
			defer wg.Done()

			k, err := fromTS.GetKeyspace(keyspace)
			if err != nil {
				rec.RecordError(fmt.Errorf("GetKeyspace(%v): %v", keyspace, err))
				return
			}

			if err := toTS.CreateKeyspace(keyspace, k.Keyspace); err != nil {
				if err == topo.ErrNodeExists {
					log.Warningf("keyspace %v already exists", keyspace)
				} else {
					rec.RecordError(fmt.Errorf("CreateKeyspace(%v): %v", keyspace, err))
				}
			}
		}(keyspace)
	}
	wg.Wait()
	if rec.HasErrors() {
		log.Fatalf("copyKeyspaces failed: %v", rec.Error())
	}
}

func DiffSchemaToArray(leftName string, left *SchemaDefinition, rightName string, right *SchemaDefinition) (result []string) {
	er := concurrency.AllErrorRecorder{}
	DiffSchema(leftName, left, rightName, right, &er)
	if er.HasErrors() {
		return er.ErrorStrings()
	} else {
		return nil
	}
}

func DiffPermissionsToArray(leftName string, left *Permissions, rightName string, right *Permissions) (result []string) {
	er := concurrency.AllErrorRecorder{}
	DiffPermissions(leftName, left, rightName, right, &er)
	if er.HasErrors() {
		return er.ErrorStrings()
	} else {
		return nil
	}
}

func (wr *Wrangler) ValidateVersionKeyspace(keyspace string) error {
	// find all the shards
	shards, err := wr.ts.GetShardNames(keyspace)
	if err != nil {
		return err
	}

	// corner cases
	if len(shards) == 0 {
		return fmt.Errorf("No shards in keyspace %v", keyspace)
	}
	sort.Strings(shards)
	if len(shards) == 1 {
		return wr.ValidateVersionShard(keyspace, shards[0])
	}

	// find the reference version using the first shard's master
	si, err := wr.ts.GetShard(keyspace, shards[0])
	if err != nil {
		return err
	}
	if si.MasterAlias.Uid == topo.NO_TABLET {
		return fmt.Errorf("No master in shard %v/%v", keyspace, shards[0])
	}
	referenceAlias := si.MasterAlias
	log.Infof("Gathering version for reference master %v", referenceAlias)
	referenceVersion, err := wr.GetVersion(referenceAlias)
	if err != nil {
		return err
	}

	// then diff with all tablets but master 0
	er := concurrency.AllErrorRecorder{}
	wg := sync.WaitGroup{}
	for _, shard := range shards {
		aliases, err := topo.FindAllTabletAliasesInShard(context.TODO(), wr.ts, keyspace, shard)
		if err != nil {
			er.RecordError(err)
			continue
		}

		for _, alias := range aliases {
			if alias == si.MasterAlias {
				continue
			}

			wg.Add(1)
			go wr.diffVersion(referenceVersion, referenceAlias, alias, &wg, &er)
		}
	}
	wg.Wait()
	if er.HasErrors() {
		return fmt.Errorf("Version diffs:\n%v", er.Error().Error())
	}
	return nil
}

// CopyShardReplications will create the ShardReplication objects in
// the destination topo
func CopyShardReplications(fromTS, toTS topo.Server) {
	keyspaces, err := fromTS.GetKeyspaces()
	if err != nil {
		log.Fatalf("fromTS.GetKeyspaces: %v", err)
	}

	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	for _, keyspace := range keyspaces {
		wg.Add(1)
		go func(keyspace string) {
			defer wg.Done()
			shards, err := fromTS.GetShardNames(keyspace)
			if err != nil {
				rec.RecordError(fmt.Errorf("GetShardNames(%v): %v", keyspace, err))
				return
			}

			for _, shard := range shards {
				wg.Add(1)
				go func(keyspace, shard string) {
					defer wg.Done()

					// read the source shard to get the cells
					si, err := fromTS.GetShard(keyspace, shard)
					if err != nil {
						rec.RecordError(fmt.Errorf("GetShard(%v, %v): %v", keyspace, shard, err))
						return
					}

					for _, cell := range si.Cells {
						sri, err := fromTS.GetShardReplication(cell, keyspace, shard)
						if err != nil {
							rec.RecordError(fmt.Errorf("GetShardReplication(%v, %v, %v): %v", cell, keyspace, shard, err))
							continue
						}

						if err := toTS.UpdateShardReplicationFields(cell, keyspace, shard, func(oldSR *topo.ShardReplication) error {
							*oldSR = *sri.ShardReplication
							return nil
						}); err != nil {
							rec.RecordError(fmt.Errorf("UpdateShardReplicationFields(%v, %v, %v): %v", cell, keyspace, shard, err))
						}
					}
				}(keyspace, shard)
			}
		}(keyspace)
	}
	wg.Wait()
	if rec.HasErrors() {
		log.Fatalf("copyShards failed: %v", rec.Error())
	}
}

// CopyTablets will create the tablets in the destination topo
func CopyTablets(fromTS, toTS topo.Server) {
	cells, err := fromTS.GetKnownCells()
	if err != nil {
		log.Fatalf("fromTS.GetKnownCells: %v", err)
	}

	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	for _, cell := range cells {
		wg.Add(1)
		go func(cell string) {
			defer wg.Done()
			tabletAliases, err := fromTS.GetTabletsByCell(cell)
			if err != nil {
				rec.RecordError(fmt.Errorf("GetTabletsByCell(%v): %v", cell, err))
			} else {
				for _, tabletAlias := range tabletAliases {
					wg.Add(1)
					go func(tabletAlias topo.TabletAlias) {
						defer wg.Done()

						// read the source tablet
						ti, err := fromTS.GetTablet(tabletAlias)
						if err != nil {
							rec.RecordError(fmt.Errorf("GetTablet(%v): %v", tabletAlias, err))
							return
						}

						// try to create the destination
						err = toTS.CreateTablet(ti.Tablet)
						if err == topo.ErrNodeExists {
							// update the destination tablet
							log.Warningf("tablet %v already exists, updating it", tabletAlias)
							err = toTS.UpdateTabletFields(ti.Alias, func(t *topo.Tablet) error {
								*t = *ti.Tablet
								return nil
							})
						}
						if err != nil {
							rec.RecordError(fmt.Errorf("CreateTablet(%v): %v", tabletAlias, err))
							return
						}
					}(tabletAlias)
				}
			}
		}(cell)
	}
	wg.Wait()
	if rec.HasErrors() {
		log.Fatalf("copyTablets failed: %v", rec.Error())
	}
}

// shardsWithSources returns all the shards that have SourceShards set
// with no Tables list.
func shardsWithSources(wr *wrangler.Wrangler) ([]map[string]string, error) {
	keyspaces, err := wr.TopoServer().GetKeyspaces()
	if err != nil {
		return nil, err
	}

	wg := sync.WaitGroup{}
	mu := sync.Mutex{} // protects result
	result := make([]map[string]string, 0, len(keyspaces))
	rec := concurrency.AllErrorRecorder{}
	for _, keyspace := range keyspaces {
		wg.Add(1)
		go func(keyspace string) {
			defer wg.Done()
			shards, err := wr.TopoServer().GetShardNames(keyspace)
			if err != nil {
				rec.RecordError(err)
				return
			}
			for _, shard := range shards {
				wg.Add(1)
				go func(keyspace, shard string) {
					defer wg.Done()
					si, err := wr.TopoServer().GetShard(keyspace, shard)
					if err != nil {
						rec.RecordError(err)
						return
					}

					if len(si.SourceShards) > 0 && len(si.SourceShards[0].Tables) == 0 {
						mu.Lock()
						result = append(result, map[string]string{
							"Keyspace": keyspace,
							"Shard":    shard,
						})
						mu.Unlock()
					}
				}(keyspace, shard)
			}
		}(keyspace)
	}
	wg.Wait()

	if rec.HasErrors() {
		return nil, rec.Error()
	}
	if len(result) == 0 {
		return nil, fmt.Errorf("There are no shards with SourceShards")
	}
	return result, nil
}

// InitializeConnections pre-initializes all ShardConn which create underlying connections.
// It also populates topology cache by accessing it.
// It is not necessary to call this function before serving queries,
// but it would reduce connection overhead when serving.
func (stc *ScatterConn) InitializeConnections(ctx context.Context) error {
	ksNames, err := stc.toposerv.GetSrvKeyspaceNames(ctx, stc.cell)
	if err != nil {
		return err
	}
	var wg sync.WaitGroup
	var errRecorder concurrency.AllErrorRecorder
	for _, ksName := range ksNames {
		wg.Add(1)
		go func(keyspace string) {
			defer wg.Done()
			// get SrvKeyspace for cell/keyspace
			ks, err := stc.toposerv.GetSrvKeyspace(ctx, stc.cell, keyspace)
			if err != nil {
				errRecorder.RecordError(err)
				return
			}
			// work on all shards of all serving tablet types
			for _, tabletType := range ks.TabletTypes {
				ksPartition, ok := ks.Partitions[tabletType]
				if !ok {
					errRecorder.RecordError(fmt.Errorf("%v.%v is not in SrvKeyspace.Partitions", keyspace, string(tabletType)))
					continue
				}
				for _, shard := range ksPartition.Shards {
					wg.Add(1)
					go func(shardName string, tabletType topo.TabletType) {
						defer wg.Done()
						shardConn := stc.getConnection(ctx, keyspace, shardName, tabletType)
						err = shardConn.Dial(ctx)
						if err != nil {
							errRecorder.RecordError(err)
							return
						}
					}(shard.ShardName(), tabletType)
				}
			}
		}(ksName)
	}
	wg.Wait()
	if errRecorder.HasErrors() {
		return errRecorder.Error()
	}
	return nil
}

func (wr *Wrangler) ValidateVersionShard(keyspace, shard string) error {
	si, err := wr.ts.GetShard(keyspace, shard)
	if err != nil {
		return err
	}

	// get version from the master, or error
	if si.MasterAlias.Uid == topo.NO_TABLET {
		return fmt.Errorf("No master in shard %v/%v", keyspace, shard)
	}
	log.Infof("Gathering version for master %v", si.MasterAlias)
	masterVersion, err := wr.GetVersion(si.MasterAlias)
	if err != nil {
		return err
	}

	// read all the aliases in the shard, that is all tablets that are
	// replicating from the master
	aliases, err := topo.FindAllTabletAliasesInShard(context.TODO(), wr.ts, keyspace, shard)
	if err != nil {
		return err
	}

	// then diff with all slaves
	er := concurrency.AllErrorRecorder{}
	wg := sync.WaitGroup{}
	for _, alias := range aliases {
		if alias == si.MasterAlias {
			continue
		}

		wg.Add(1)
		go wr.diffVersion(masterVersion, si.MasterAlias, alias, &wg, &er)
	}
	wg.Wait()
	if er.HasErrors() {
		return fmt.Errorf("Version diffs:\n%v", er.Error().Error())
	}
	return nil
}

func keyspacesWithOverlappingShards(wr *wrangler.Wrangler) ([]map[string]string, error) {
	keyspaces, err := wr.TopoServer().GetKeyspaces()
	if err != nil {
		return nil, err
	}

	wg := sync.WaitGroup{}
	mu := sync.Mutex{} // protects result
	result := make([]map[string]string, 0, len(keyspaces))
	rec := concurrency.AllErrorRecorder{}
	for _, keyspace := range keyspaces {
		wg.Add(1)
		go func(keyspace string) {
			defer wg.Done()
			osList, err := topotools.FindOverlappingShards(wr.TopoServer(), keyspace)
			if err != nil {
				rec.RecordError(err)
				return
			}
			mu.Lock()
			for _, os := range osList {
				result = append(result, map[string]string{
					"Keyspace": os.Left[0].Keyspace(),
					"Shard":    os.Left[0].ShardName(),
				})
			}
			mu.Unlock()
		}(keyspace)
	}
	wg.Wait()

	if rec.HasErrors() {
		return nil, rec.Error()
	}
	if len(result) == 0 {
		return nil, fmt.Errorf("There are no keyspaces with overlapping shards")
	}
	return result, nil
}

// keyspacesWithServedFrom returns all the keyspaces that have ServedFrom set
// to one value.
func keyspacesWithServedFrom(wr *wrangler.Wrangler) ([]string, error) {
	keyspaces, err := wr.TopoServer().GetKeyspaces()
	if err != nil {
		return nil, err
	}

	wg := sync.WaitGroup{}
	mu := sync.Mutex{} // protects result
	result := make([]string, 0, len(keyspaces))
	rec := concurrency.AllErrorRecorder{}
	for _, keyspace := range keyspaces {
		wg.Add(1)
		go func(keyspace string) {
			defer wg.Done()
			ki, err := wr.TopoServer().GetKeyspace(keyspace)
			if err != nil {
				rec.RecordError(err)
				return
			}
			if len(ki.ServedFromMap) > 0 {
				mu.Lock()
				result = append(result, keyspace)
				mu.Unlock()
			}
		}(keyspace)
	}
	wg.Wait()

	if rec.HasErrors() {
		return nil, rec.Error()
	}
	if len(result) == 0 {
		return nil, fmt.Errorf("There are no keyspaces with ServedFrom")
	}
	return result, nil
}

func (vsdw *VerticalSplitDiffWorker) diff() error {
	vsdw.setState(stateVSDDiff)

	vsdw.wr.Logger().Infof("Gathering schema information...")
	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	wg.Add(1)
	go func() {
		var err error
		vsdw.destinationSchemaDefinition, err = vsdw.wr.GetSchema(vsdw.destinationAlias, nil, nil, false)
		rec.RecordError(err)
		vsdw.wr.Logger().Infof("Got schema from destination %v", vsdw.destinationAlias)
		wg.Done()
	}()
	wg.Add(1)
	go func() {
		var err error
		vsdw.sourceSchemaDefinition, err = vsdw.wr.GetSchema(vsdw.sourceAlias, nil, nil, false)
		rec.RecordError(err)
		vsdw.wr.Logger().Infof("Got schema from source %v", vsdw.sourceAlias)
		wg.Done()
	}()
	wg.Wait()
	if rec.HasErrors() {
		return rec.Error()
	}

	// Build a list of regexp to exclude tables from source schema
	tableRegexps := make([]*regexp.Regexp, len(vsdw.shardInfo.SourceShards[0].Tables))
	for i, table := range vsdw.shardInfo.SourceShards[0].Tables {
		var err error
		tableRegexps[i], err = regexp.Compile(table)
		if err != nil {
			return fmt.Errorf("cannot compile regexp %v for table: %v", table, err)
		}
	}

	// Remove the tables we don't need from the source schema
	newSourceTableDefinitions := make([]*myproto.TableDefinition, 0, len(vsdw.destinationSchemaDefinition.TableDefinitions))
	for _, tableDefinition := range vsdw.sourceSchemaDefinition.TableDefinitions {
		found := false
		for _, tableRegexp := range tableRegexps {
			if tableRegexp.MatchString(tableDefinition.Name) {
				found = true
				break
			}
		}
		if !found {
			vsdw.wr.Logger().Infof("Removing table %v from source schema", tableDefinition.Name)
			continue
		}
		newSourceTableDefinitions = append(newSourceTableDefinitions, tableDefinition)
	}
	vsdw.sourceSchemaDefinition.TableDefinitions = newSourceTableDefinitions

	// Check the schema
	vsdw.wr.Logger().Infof("Diffing the schema...")
	rec = concurrency.AllErrorRecorder{}
	myproto.DiffSchema("destination", vsdw.destinationSchemaDefinition, "source", vsdw.sourceSchemaDefinition, &rec)
	if rec.HasErrors() {
		vsdw.wr.Logger().Warningf("Different schemas: %v", rec.Error())
	} else {
		vsdw.wr.Logger().Infof("Schema match, good.")
	}

	// run the diffs, 8 at a time
	vsdw.wr.Logger().Infof("Running the diffs...")
	sem := sync2.NewSemaphore(8, 0)
	for _, tableDefinition := range vsdw.destinationSchemaDefinition.TableDefinitions {
		wg.Add(1)
		go func(tableDefinition *myproto.TableDefinition) {
			defer wg.Done()
			sem.Acquire()
			defer sem.Release()

			vsdw.wr.Logger().Infof("Starting the diff on table %v", tableDefinition.Name)
			sourceQueryResultReader, err := TableScan(vsdw.wr.Logger(), vsdw.wr.TopoServer(), vsdw.sourceAlias, tableDefinition)
			if err != nil {
				vsdw.wr.Logger().Errorf("TableScan(source) failed: %v", err)
				return
			}
			defer sourceQueryResultReader.Close()

			destinationQueryResultReader, err := TableScan(vsdw.wr.Logger(), vsdw.wr.TopoServer(), vsdw.destinationAlias, tableDefinition)
			if err != nil {
				vsdw.wr.Logger().Errorf("TableScan(destination) failed: %v", err)
				return
			}
			defer destinationQueryResultReader.Close()

			differ, err := NewRowDiffer(sourceQueryResultReader, destinationQueryResultReader, tableDefinition)
			if err != nil {
				vsdw.wr.Logger().Errorf("NewRowDiffer() failed: %v", err)
				return
			}

			report, err := differ.Go(vsdw.wr.Logger())
			if err != nil {
				vsdw.wr.Logger().Errorf("Differ.Go failed: %v", err)
			} else {
//.........這裏部分代碼省略.........

// MigrateServedTypes is used during horizontal splits to migrate a
// served type from a list of shards to another.
func (wr *Wrangler) MigrateServedTypes(keyspace, shard string, cells []string, servedType topo.TabletType, reverse, skipReFreshState bool) error {
	if servedType == topo.TYPE_MASTER {
		// we cannot migrate a master back, since when master migration
		// is done, the source shards are dead
		if reverse {
			return fmt.Errorf("Cannot migrate master back to %v/%v", keyspace, shard)
		}
		// we cannot skip refresh state for a master
		if skipReFreshState {
			return fmt.Errorf("Cannot skip refresh state for master migration on %v/%v", keyspace, shard)
		}
	}

	// find overlapping shards in this keyspace
	wr.Logger().Infof("Finding the overlapping shards in keyspace %v", keyspace)
	osList, err := topotools.FindOverlappingShards(wr.ts, keyspace)
	if err != nil {
		return fmt.Errorf("FindOverlappingShards failed: %v", err)
	}

	// find our shard in there
	os := topotools.OverlappingShardsForShard(osList, shard)
	if os == nil {
		return fmt.Errorf("Shard %v is not involved in any overlapping shards", shard)
	}

	// find which list is which: the sources have no source
	// shards, the destination have source shards. We check the
	// first entry in the lists, then just check they're
	// consistent
	var sourceShards []*topo.ShardInfo
	var destinationShards []*topo.ShardInfo
	if len(os.Left[0].SourceShards) == 0 {
		sourceShards = os.Left
		destinationShards = os.Right
	} else {
		sourceShards = os.Right
		destinationShards = os.Left
	}

	// Verify the sources has the type we're migrating (or not if reverse)
	for _, si := range sourceShards {
		if err := si.CheckServedTypesMigration(servedType, cells, !reverse); err != nil {
			return err
		}
	}

	// Verify the destinations do not have the type we're
	// migrating (or do if reverse)
	for _, si := range destinationShards {
		if err := si.CheckServedTypesMigration(servedType, cells, reverse); err != nil {
			return err
		}
	}

	// lock the shards: sources, then destinations
	// (note they're all ordered by shard name)
	actionNode := actionnode.MigrateServedTypes(servedType)
	sourceLockPath := make([]string, len(sourceShards))
	for i, si := range sourceShards {
		sourceLockPath[i], err = wr.lockShard(si.Keyspace(), si.ShardName(), actionNode)
		if err != nil {
			wr.Logger().Errorf("Failed to lock source shard %v/%v, may need to unlock other shards manually", si.Keyspace(), si.ShardName())
			return err
		}
	}
	destinationLockPath := make([]string, len(destinationShards))
	for i, si := range destinationShards {
		destinationLockPath[i], err = wr.lockShard(si.Keyspace(), si.ShardName(), actionNode)
		if err != nil {
			wr.Logger().Errorf("Failed to lock destination shard %v/%v, may need to unlock other shards manually", si.Keyspace(), si.ShardName())
			return err
		}
	}

	// record the action error and all unlock errors
	rec := concurrency.AllErrorRecorder{}

	// execute the migration
	rec.RecordError(wr.migrateServedTypes(keyspace, sourceShards, destinationShards, cells, servedType, reverse))

	// unlock the shards, we're done
	for i := len(destinationShards) - 1; i >= 0; i-- {
		rec.RecordError(wr.unlockShard(destinationShards[i].Keyspace(), destinationShards[i].ShardName(), actionNode, destinationLockPath[i], nil))
	}
	for i := len(sourceShards) - 1; i >= 0; i-- {
		rec.RecordError(wr.unlockShard(sourceShards[i].Keyspace(), sourceShards[i].ShardName(), actionNode, sourceLockPath[i], nil))
	}

	// rebuild the keyspace serving graph if there was no error
	if !rec.HasErrors() {
		rec.RecordError(wr.RebuildKeyspaceGraph(keyspace, nil))
	}

	// Send a refresh to the source tablets we just disabled, iff:
	// - we're not migrating a master
	// - it is not a reverse migration
	// - we don't have any errors
//.........這裏部分代碼省略.........

func (sdw *SplitDiffWorker) diff() error {
	sdw.setState(stateSDDiff)

	sdw.wr.Logger().Infof("Gathering schema information...")
	sdw.sourceSchemaDefinitions = make([]*myproto.SchemaDefinition, len(sdw.sourceAliases))
	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	wg.Add(1)
	go func() {
		var err error
		sdw.destinationSchemaDefinition, err = sdw.wr.GetSchema(sdw.destinationAlias, nil, nil, false)
		rec.RecordError(err)
		sdw.wr.Logger().Infof("Got schema from destination %v", sdw.destinationAlias)
		wg.Done()
	}()
	for i, sourceAlias := range sdw.sourceAliases {
		wg.Add(1)
		go func(i int, sourceAlias topo.TabletAlias) {
			var err error
			sdw.sourceSchemaDefinitions[i], err = sdw.wr.GetSchema(sourceAlias, nil, nil, false)
			rec.RecordError(err)
			sdw.wr.Logger().Infof("Got schema from source[%v] %v", i, sourceAlias)
			wg.Done()
		}(i, sourceAlias)
	}
	wg.Wait()
	if rec.HasErrors() {
		return rec.Error()
	}

	// TODO(alainjobart) Checking against each source may be
	// overkill, if all sources have the same schema?
	sdw.wr.Logger().Infof("Diffing the schema...")
	rec = concurrency.AllErrorRecorder{}
	for i, sourceSchemaDefinition := range sdw.sourceSchemaDefinitions {
		sourceName := fmt.Sprintf("source[%v]", i)
		myproto.DiffSchema("destination", sdw.destinationSchemaDefinition, sourceName, sourceSchemaDefinition, &rec)
	}
	if rec.HasErrors() {
		sdw.wr.Logger().Warningf("Different schemas: %v", rec.Error().Error())
	} else {
		sdw.wr.Logger().Infof("Schema match, good.")
	}

	// run the diffs, 8 at a time
	sdw.wr.Logger().Infof("Running the diffs...")
	sem := sync2.NewSemaphore(8, 0)
	for _, tableDefinition := range sdw.destinationSchemaDefinition.TableDefinitions {
		wg.Add(1)
		go func(tableDefinition *myproto.TableDefinition) {
			defer wg.Done()
			sem.Acquire()
			defer sem.Release()

			sdw.wr.Logger().Infof("Starting the diff on table %v", tableDefinition.Name)
			if len(sdw.sourceAliases) != 1 {
				sdw.wr.Logger().Errorf("Don't support more than one source for table yet: %v", tableDefinition.Name)
				return
			}

			overlap, err := key.KeyRangesOverlap(sdw.shardInfo.KeyRange, sdw.shardInfo.SourceShards[0].KeyRange)
			if err != nil {
				sdw.wr.Logger().Errorf("Source shard doesn't overlap with destination????: %v", err)
				return
			}
			sourceQueryResultReader, err := TableScanByKeyRange(sdw.wr.Logger(), sdw.wr.TopoServer(), sdw.sourceAliases[0], tableDefinition, overlap, sdw.keyspaceInfo.ShardingColumnType)
			if err != nil {
				sdw.wr.Logger().Errorf("TableScanByKeyRange(source) failed: %v", err)
				return
			}
			defer sourceQueryResultReader.Close()

			destinationQueryResultReader, err := TableScanByKeyRange(sdw.wr.Logger(), sdw.wr.TopoServer(), sdw.destinationAlias, tableDefinition, key.KeyRange{}, sdw.keyspaceInfo.ShardingColumnType)
			if err != nil {
				sdw.wr.Logger().Errorf("TableScanByKeyRange(destination) failed: %v", err)
				return
			}
			defer destinationQueryResultReader.Close()

			differ, err := NewRowDiffer(sourceQueryResultReader, destinationQueryResultReader, tableDefinition)
			if err != nil {
				sdw.wr.Logger().Errorf("NewRowDiffer() failed: %v", err)
				return
			}

			report, err := differ.Go(sdw.wr.Logger())
			if err != nil {
				sdw.wr.Logger().Errorf("Differ.Go failed: %v", err.Error())
			} else {
				if report.HasDifferences() {
					sdw.wr.Logger().Warningf("Table %v has differences: %v", tableDefinition.Name, report.String())
				} else {
					sdw.wr.Logger().Infof("Table %v checks out (%v rows processed, %v qps)", tableDefinition.Name, report.processedRows, report.processingQPS)
				}
			}
		}(tableDefinition)
	}
	wg.Wait()

	return nil
//.........這裏部分代碼省略.........

// CopyShards will create the shards in the destination topo
func CopyShards(fromTS, toTS topo.Server, deleteKeyspaceShards bool) {
	keyspaces, err := fromTS.GetKeyspaces()
	if err != nil {
		log.Fatalf("fromTS.GetKeyspaces: %v", err)
	}

	wg := sync.WaitGroup{}
	rec := concurrency.AllErrorRecorder{}
	for _, keyspace := range keyspaces {
		wg.Add(1)
		go func(keyspace string) {
			defer wg.Done()
			shards, err := fromTS.GetShardNames(keyspace)
			if err != nil {
				rec.RecordError(fmt.Errorf("GetShardNames(%v): %v", keyspace, err))
				return
			}

			if deleteKeyspaceShards {
				if err := toTS.DeleteKeyspaceShards(keyspace); err != nil {
					rec.RecordError(fmt.Errorf("DeleteKeyspaceShards(%v): %v", keyspace, err))
					return
				}
			}

			for _, shard := range shards {
				wg.Add(1)
				go func(keyspace, shard string) {
					defer wg.Done()
					if err := topo.CreateShard(toTS, keyspace, shard); err != nil {
						if err == topo.ErrNodeExists {
							log.Warningf("shard %v/%v already exists", keyspace, shard)
						} else {
							rec.RecordError(fmt.Errorf("CreateShard(%v, %v): %v", keyspace, shard, err))
							return
						}
					}

					si, err := fromTS.GetShard(keyspace, shard)
					if err != nil {
						rec.RecordError(fmt.Errorf("GetShard(%v, %v): %v", keyspace, shard, err))
						return
					}

					toSi, err := toTS.GetShard(keyspace, shard)
					if err != nil {
						rec.RecordError(fmt.Errorf("toTS.GetShard(%v, %v): %v", keyspace, shard, err))
						return
					}

					if _, err := toTS.UpdateShard(si, toSi.Version()); err != nil {
						rec.RecordError(fmt.Errorf("UpdateShard(%v, %v): %v", keyspace, shard, err))
					}
				}(keyspace, shard)
			}
		}(keyspace)
	}
	wg.Wait()
	if rec.HasErrors() {
		log.Fatalf("copyShards failed: %v", rec.Error())
	}
}