func (scw *SplitCloneWorker) loadVSchema(ctx context.Context) error {
var keyspaceSchema *vindexes.KeyspaceSchema
if *useV3ReshardingMode {
kschema, err := scw.wr.TopoServer().GetVSchema(ctx, scw.destinationKeyspace)
if err != nil {
return fmt.Errorf("cannot load VSchema for keyspace %v: %v", scw.destinationKeyspace, err)
}
if kschema == nil {
return fmt.Errorf("no VSchema for keyspace %v", scw.destinationKeyspace)
}
keyspaceSchema, err = vindexes.BuildKeyspaceSchema(kschema, scw.destinationKeyspace)
if err != nil {
return fmt.Errorf("cannot build vschema for keyspace %v: %v", scw.destinationKeyspace, err)
}
scw.keyspaceSchema = keyspaceSchema
}
return nil
}
// copy phase:
// - copy the data from source tablets to destination masters (with replication on)
// Assumes that the schema has already been created on each destination tablet
// (probably from vtctl's CopySchemaShard)
func (scw *LegacySplitCloneWorker) copy(ctx context.Context) error {
scw.setState(WorkerStateCloneOffline)
start := time.Now()
defer func() {
statsStateDurationsNs.Set(string(WorkerStateCloneOffline), time.Now().Sub(start).Nanoseconds())
}()
// get source schema from the first shard
// TODO(alainjobart): for now, we assume the schema is compatible
// on all source shards. Furthermore, we estimate the number of rows
// in each source shard for each table to be about the same
// (rowCount is used to estimate an ETA)
shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
sourceSchemaDefinition, err := scw.wr.GetSchema(shortCtx, scw.sourceAliases[0], nil, scw.excludeTables, false /* includeViews */)
cancel()
if err != nil {
return fmt.Errorf("cannot get schema from source %v: %v", topoproto.TabletAliasString(scw.sourceAliases[0]), err)
}
if len(sourceSchemaDefinition.TableDefinitions) == 0 {
return fmt.Errorf("no tables matching the table filter in tablet %v", topoproto.TabletAliasString(scw.sourceAliases[0]))
}
for _, td := range sourceSchemaDefinition.TableDefinitions {
if len(td.Columns) == 0 {
return fmt.Errorf("schema for table %v has no columns", td.Name)
}
}
scw.wr.Logger().Infof("Source tablet 0 has %v tables to copy", len(sourceSchemaDefinition.TableDefinitions))
scw.tableStatusList.initialize(sourceSchemaDefinition)
// In parallel, setup the channels to send SQL data chunks to for each destination tablet:
//
// mu protects the context for cancelation, and firstError
mu := sync.Mutex{}
var firstError error
ctx, cancelCopy := context.WithCancel(ctx)
processError := func(format string, args ...interface{}) {
scw.wr.Logger().Errorf(format, args...)
mu.Lock()
if firstError == nil {
firstError = fmt.Errorf(format, args...)
cancelCopy()
}
mu.Unlock()
}
insertChannels := make([]chan string, len(scw.destinationShards))
destinationWaitGroup := sync.WaitGroup{}
for shardIndex, si := range scw.destinationShards {
// we create one channel per destination tablet. It
// is sized to have a buffer of a maximum of
// destinationWriterCount * 2 items, to hopefully
// always have data. We then have
// destinationWriterCount go routines reading from it.
insertChannels[shardIndex] = make(chan string, scw.destinationWriterCount*2)
go func(keyspace, shard string, insertChannel chan string) {
for j := 0; j < scw.destinationWriterCount; j++ {
destinationWaitGroup.Add(1)
go func(threadID int) {
defer destinationWaitGroup.Done()
keyspaceAndShard := topoproto.KeyspaceShardString(keyspace, shard)
throttler := scw.destinationThrottlers[keyspaceAndShard]
defer throttler.ThreadFinished(threadID)
executor := newExecutor(scw.wr, scw.tsc, throttler, keyspace, shard, threadID)
if err := executor.fetchLoop(ctx, insertChannel); err != nil {
processError("executer.FetchLoop failed: %v", err)
}
}(j)
}
}(si.Keyspace(), si.ShardName(), insertChannels[shardIndex])
}
// read the vschema if needed
var keyspaceSchema *vindexes.KeyspaceSchema
if *useV3ReshardingMode {
kschema, err := scw.wr.TopoServer().GetVSchema(ctx, scw.keyspace)
if err != nil {
return fmt.Errorf("cannot load VSchema for keyspace %v: %v", scw.keyspace, err)
}
if kschema == nil {
return fmt.Errorf("no VSchema for keyspace %v", scw.keyspace)
}
keyspaceSchema, err = vindexes.BuildKeyspaceSchema(kschema, scw.keyspace)
if err != nil {
return fmt.Errorf("cannot build vschema for keyspace %v: %v", scw.keyspace, err)
}
}
// Now for each table, read data chunks and send them to all
// insertChannels
sourceWaitGroup := sync.WaitGroup{}
for shardIndex := range scw.sourceShards {
sema := sync2.NewSemaphore(scw.sourceReaderCount, 0)
for tableIndex, td := range sourceSchemaDefinition.TableDefinitions {
var keyResolver keyspaceIDResolver
if *useV3ReshardingMode {
keyResolver, err = newV3ResolverFromTableDefinition(keyspaceSchema, td)
if err != nil {
return fmt.Errorf("cannot resolve v3 sharding keys for keyspace %v: %v", scw.keyspace, err)
}
} else {
keyResolver, err = newV2Resolver(scw.keyspaceInfo, td)
if err != nil {
return fmt.Errorf("cannot resolve sharding keys for keyspace %v: %v", scw.keyspace, err)
}
}
rowSplitter := NewRowSplitter(scw.destinationShards, keyResolver)
chunks, err := generateChunks(ctx, scw.wr, scw.sourceTablets[shardIndex], td, scw.sourceReaderCount, defaultMinRowsPerChunk)
if err != nil {
return err
}
scw.tableStatusList.setThreadCount(tableIndex, len(chunks)-1)
for _, c := range chunks {
sourceWaitGroup.Add(1)
go func(td *tabletmanagerdatapb.TableDefinition, tableIndex int, chunk chunk) {
defer sourceWaitGroup.Done()
sema.Acquire()
defer sema.Release()
scw.tableStatusList.threadStarted(tableIndex)
// Start streaming from the source tablets.
tp := newSingleTabletProvider(ctx, scw.wr.TopoServer(), scw.sourceAliases[shardIndex])
rr, err := NewRestartableResultReader(ctx, scw.wr.Logger(), tp, td, chunk, false /* allowMultipleRetries */)
if err != nil {
processError("NewRestartableResultReader failed: %v", err)
return
}
defer rr.Close(ctx)
// process the data
dbNames := make([]string, len(scw.destinationShards))
for i, si := range scw.destinationShards {
keyspaceAndShard := topoproto.KeyspaceShardString(si.Keyspace(), si.ShardName())
dbNames[i] = scw.destinationDbNames[keyspaceAndShard]
}
if err := scw.processData(ctx, dbNames, td, tableIndex, rr, rowSplitter, insertChannels, scw.destinationPackCount); err != nil {
processError("processData failed: %v", err)
}
scw.tableStatusList.threadDone(tableIndex)
}(td, tableIndex, c)
}
}
}
sourceWaitGroup.Wait()
for shardIndex := range scw.destinationShards {
close(insertChannels[shardIndex])
}
destinationWaitGroup.Wait()
if firstError != nil {
return firstError
}
// then create and populate the blp_checkpoint table
if scw.strategy.skipPopulateBlpCheckpoint {
scw.wr.Logger().Infof("Skipping populating the blp_checkpoint table")
} else {
queries := make([]string, 0, 4)
queries = append(queries, binlogplayer.CreateBlpCheckpoint()...)
flags := ""
if scw.strategy.dontStartBinlogPlayer {
flags = binlogplayer.BlpFlagDontStart
}
// get the current position from the sources
for shardIndex := range scw.sourceShards {
shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
status, err := scw.wr.TabletManagerClient().SlaveStatus(shortCtx, scw.sourceTablets[shardIndex])
cancel()
if err != nil {
return err
}
queries = append(queries, binlogplayer.PopulateBlpCheckpoint(uint32(shardIndex), status.Position, scw.maxTPS, throttler.ReplicationLagModuleDisabled, time.Now().Unix(), flags))
}
for _, si := range scw.destinationShards {
destinationWaitGroup.Add(1)
go func(keyspace, shard string) {
defer destinationWaitGroup.Done()
scw.wr.Logger().Infof("Making and populating blp_checkpoint table")
keyspaceAndShard := topoproto.KeyspaceShardString(keyspace, shard)
if err := runSQLCommands(ctx, scw.wr, scw.tsc, keyspace, shard, scw.destinationDbNames[keyspaceAndShard], queries); err != nil {
processError("blp_checkpoint queries failed: %v", err)
}
}(si.Keyspace(), si.ShardName())
}
destinationWaitGroup.Wait()
if firstError != nil {
return firstError
}
}
// Now we're done with data copy, update the shard's source info.
// TODO(alainjobart) this is a superset, some shards may not
// overlap, have to deal with this better (for N -> M splits
// where both N>1 and M>1)
if scw.strategy.skipSetSourceShards {
scw.wr.Logger().Infof("Skipping setting SourceShard on destination shards.")
} else {
for _, si := range scw.destinationShards {
scw.wr.Logger().Infof("Setting SourceShard on shard %v/%v", si.Keyspace(), si.ShardName())
shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
err := scw.wr.SetSourceShards(shortCtx, si.Keyspace(), si.ShardName(), scw.sourceAliases, nil)
cancel()
if err != nil {
return fmt.Errorf("failed to set source shards: %v", err)
}
}
}
err = scw.findRefreshTargets(ctx)
if err != nil {
return fmt.Errorf("failed before refreshing state on destination tablets: %v", err)
}
// And force a state refresh (re-read topo) on all destination tablets.
// The master tablet will end up starting filtered replication
// at this point.
for shardIndex := range scw.destinationShards {
for _, tabletAlias := range scw.refreshAliases[shardIndex] {
destinationWaitGroup.Add(1)
go func(ti *topo.TabletInfo) {
defer destinationWaitGroup.Done()
scw.wr.Logger().Infof("Refreshing state on tablet %v", ti.AliasString())
shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
err := scw.wr.TabletManagerClient().RefreshState(shortCtx, ti.Tablet)
cancel()
if err != nil {
processError("RefreshState failed on tablet %v: %v", ti.AliasString(), err)
}
}(scw.refreshTablets[shardIndex][*tabletAlias])
}
}
destinationWaitGroup.Wait()
return firstError
}
// init phase:
// - read the destination keyspace, make sure it has 'servedFrom' values
func (scw *SplitCloneWorker) init(ctx context.Context) error {
scw.setState(WorkerStateInit)
var err error
// read the keyspace and validate it
shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
scw.keyspaceInfo, err = scw.wr.TopoServer().GetKeyspace(shortCtx, scw.keyspace)
cancel()
if err != nil {
return fmt.Errorf("cannot read keyspace %v: %v", scw.keyspace, err)
}
// find the OverlappingShards in the keyspace
shortCtx, cancel = context.WithTimeout(ctx, *remoteActionsTimeout)
osList, err := topotools.FindOverlappingShards(shortCtx, scw.wr.TopoServer(), scw.keyspace)
cancel()
if err != nil {
return fmt.Errorf("cannot FindOverlappingShards in %v: %v", scw.keyspace, err)
}
// find the shard we mentioned in there, if any
os := topotools.OverlappingShardsForShard(osList, scw.shard)
if os == nil {
return fmt.Errorf("the specified shard %v/%v is not in any overlapping shard", scw.keyspace, scw.shard)
}
scw.wr.Logger().Infof("Found overlapping shards: %+v\n", os)
// one side should have served types, the other one none,
// figure out wich is which, then double check them all
if len(os.Left[0].ServedTypes) > 0 {
scw.sourceShards = os.Left
scw.destinationShards = os.Right
} else {
scw.sourceShards = os.Right
scw.destinationShards = os.Left
}
// Verify that filtered replication is not already enabled.
for _, si := range scw.destinationShards {
if len(si.SourceShards) > 0 {
return fmt.Errorf("destination shard %v/%v has filtered replication already enabled from a previous resharding (ShardInfo is set)."+
" This requires manual intervention e.g. use vtctl SourceShardDelete to remove it",
si.Keyspace(), si.ShardName())
}
}
// validate all serving types
servingTypes := []topodatapb.TabletType{topodatapb.TabletType_MASTER, topodatapb.TabletType_REPLICA, topodatapb.TabletType_RDONLY}
for _, st := range servingTypes {
for _, si := range scw.sourceShards {
if si.GetServedType(st) == nil {
return fmt.Errorf("source shard %v/%v is not serving type %v", si.Keyspace(), si.ShardName(), st)
}
}
}
for _, si := range scw.destinationShards {
if len(si.ServedTypes) > 0 {
return fmt.Errorf("destination shard %v/%v is serving some types", si.Keyspace(), si.ShardName())
}
}
// read the vschema if needed
var keyspaceSchema *vindexes.KeyspaceSchema
if *useV3ReshardingMode {
kschema, err := scw.wr.TopoServer().GetVSchema(ctx, scw.keyspace)
if err != nil {
return fmt.Errorf("cannot load VSchema for keyspace %v: %v", scw.keyspace, err)
}
if kschema == nil {
return fmt.Errorf("no VSchema for keyspace %v", scw.keyspace)
}
keyspaceSchema, err = vindexes.BuildKeyspaceSchema(kschema, scw.keyspace)
if err != nil {
return fmt.Errorf("cannot build vschema for keyspace %v: %v", scw.keyspace, err)
}
scw.keyspaceSchema = keyspaceSchema
}
// Initialize healthcheck and add destination shards to it.
scw.healthCheck = discovery.NewHealthCheck(*remoteActionsTimeout, *healthcheckRetryDelay, *healthCheckTimeout)
allShards := append(scw.sourceShards, scw.destinationShards...)
for _, si := range allShards {
watcher := discovery.NewShardReplicationWatcher(scw.wr.TopoServer(), scw.healthCheck,
scw.cell, si.Keyspace(), si.ShardName(),
*healthCheckTopologyRefresh, discovery.DefaultTopoReadConcurrency)
scw.shardWatchers = append(scw.shardWatchers, watcher)
}
return nil
}
func (sdw *SplitDiffWorker) diff(ctx context.Context) error {
sdw.SetState(WorkerStateDiff)
sdw.wr.Logger().Infof("Gathering schema information...")
wg := sync.WaitGroup{}
rec := &concurrency.AllErrorRecorder{}
wg.Add(1)
go func() {
var err error
shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
sdw.destinationSchemaDefinition, err = sdw.wr.GetSchema(
shortCtx, sdw.destinationAlias, nil /* tables */, sdw.excludeTables, false /* includeViews */)
cancel()
rec.RecordError(err)
sdw.wr.Logger().Infof("Got schema from destination %v", sdw.destinationAlias)
wg.Done()
}()
wg.Add(1)
go func() {
var err error
shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
sdw.sourceSchemaDefinition, err = sdw.wr.GetSchema(
shortCtx, sdw.sourceAlias, nil /* tables */, sdw.excludeTables, false /* includeViews */)
cancel()
rec.RecordError(err)
sdw.wr.Logger().Infof("Got schema from source %v", sdw.sourceAlias)
wg.Done()
}()
wg.Wait()
if rec.HasErrors() {
return rec.Error()
}
sdw.wr.Logger().Infof("Diffing the schema...")
rec = &concurrency.AllErrorRecorder{}
tmutils.DiffSchema("destination", sdw.destinationSchemaDefinition, "source", sdw.sourceSchemaDefinition, rec)
if rec.HasErrors() {
sdw.wr.Logger().Warningf("Different schemas: %v", rec.Error().Error())
} else {
sdw.wr.Logger().Infof("Schema match, good.")
}
// read the vschema if needed
var keyspaceSchema *vindexes.KeyspaceSchema
if *useV3ReshardingMode {
kschema, err := sdw.wr.TopoServer().GetVSchema(ctx, sdw.keyspace)
if err != nil {
return fmt.Errorf("cannot load VSchema for keyspace %v: %v", sdw.keyspace, err)
}
if kschema == nil {
return fmt.Errorf("no VSchema for keyspace %v", sdw.keyspace)
}
keyspaceSchema, err = vindexes.BuildKeyspaceSchema(kschema, sdw.keyspace)
if err != nil {
return fmt.Errorf("cannot build vschema for keyspace %v: %v", sdw.keyspace, err)
}
}
// Compute the overlap keyrange. Later, we'll compare it with
// source or destination keyrange. If it matches either,
// we'll just ask for all the data. If the overlap is a subset,
// we'll filter.
overlap, err := key.KeyRangesOverlap(sdw.shardInfo.KeyRange, sdw.shardInfo.SourceShards[sdw.sourceUID].KeyRange)
if err != nil {
return fmt.Errorf("Source shard doesn't overlap with destination: %v", err)
}
// run the diffs, 8 at a time
sdw.wr.Logger().Infof("Running the diffs...")
// TODO(mberlin): Parameterize the hard coded value 8.
sem := sync2.NewSemaphore(8, 0)
for _, tableDefinition := range sdw.destinationSchemaDefinition.TableDefinitions {
wg.Add(1)
go func(tableDefinition *tabletmanagerdatapb.TableDefinition) {
defer wg.Done()
sem.Acquire()
defer sem.Release()
sdw.wr.Logger().Infof("Starting the diff on table %v", tableDefinition.Name)
// On the source, see if we need a full scan
// or a filtered scan.
var sourceQueryResultReader *QueryResultReader
if key.KeyRangeEqual(overlap, sdw.shardInfo.SourceShards[sdw.sourceUID].KeyRange) {
sourceQueryResultReader, err = TableScan(ctx, sdw.wr.Logger(), sdw.wr.TopoServer(), sdw.sourceAlias, tableDefinition)
} else {
sourceQueryResultReader, err = TableScanByKeyRange(ctx, sdw.wr.Logger(), sdw.wr.TopoServer(), sdw.sourceAlias, tableDefinition, overlap, keyspaceSchema, sdw.keyspaceInfo.ShardingColumnName, sdw.keyspaceInfo.ShardingColumnType)
}
if err != nil {
newErr := fmt.Errorf("TableScan(ByKeyRange?)(source) failed: %v", err)
rec.RecordError(newErr)
sdw.wr.Logger().Errorf("%v", newErr)
return
}
defer sourceQueryResultReader.Close(ctx)
// On the destination, see if we need a full scan
// or a filtered scan.
var destinationQueryResultReader *QueryResultReader
if key.KeyRangeEqual(overlap, sdw.shardInfo.KeyRange) {
destinationQueryResultReader, err = TableScan(ctx, sdw.wr.Logger(), sdw.wr.TopoServer(), sdw.destinationAlias, tableDefinition)
} else {
destinationQueryResultReader, err = TableScanByKeyRange(ctx, sdw.wr.Logger(), sdw.wr.TopoServer(), sdw.destinationAlias, tableDefinition, overlap, keyspaceSchema, sdw.keyspaceInfo.ShardingColumnName, sdw.keyspaceInfo.ShardingColumnType)
}
if err != nil {
newErr := fmt.Errorf("TableScan(ByKeyRange?)(destination) failed: %v", err)
rec.RecordError(newErr)
sdw.wr.Logger().Errorf("%v", newErr)
return
}
defer destinationQueryResultReader.Close(ctx)
// Create the row differ.
differ, err := NewRowDiffer(sourceQueryResultReader, destinationQueryResultReader, tableDefinition)
if err != nil {
newErr := fmt.Errorf("NewRowDiffer() failed: %v", err)
rec.RecordError(newErr)
sdw.wr.Logger().Errorf("%v", newErr)
return
}
// And run the diff.
report, err := differ.Go(sdw.wr.Logger())
if err != nil {
newErr := fmt.Errorf("Differ.Go failed: %v", err.Error())
rec.RecordError(newErr)
sdw.wr.Logger().Errorf("%v", newErr)
} else {
if report.HasDifferences() {
err := fmt.Errorf("Table %v has differences: %v", tableDefinition.Name, report.String())
rec.RecordError(err)
sdw.wr.Logger().Warningf(err.Error())
} else {
sdw.wr.Logger().Infof("Table %v checks out (%v rows processed, %v qps)", tableDefinition.Name, report.processedRows, report.processingQPS)
}
}
}(tableDefinition)
}
wg.Wait()
return rec.Error()
}