// ExecuteVtctlCommand is the server side method that will execute the query,
// and stream the results.
func (s *VtctlServer) ExecuteVtctlCommand(context context.Context, query *gorpcproto.ExecuteVtctlCommandArgs, sendReply func(interface{}) error) error {
// create a logger, send the result back to the caller
logstream := logutil.NewChannelLogger(10)
logger := logutil.NewTeeLogger(logstream, logutil.NewConsoleLogger())
// send logs to the caller
wg := sync.WaitGroup{}
wg.Add(1)
go func() {
for e := range logstream {
// Note we don't interrupt the loop here, as
// we still need to flush and finish the
// command, even if the channel to the client
// has been broken. We'll just keep trying.
sendReply(&e)
}
wg.Done()
}()
// create the wrangler
wr := wrangler.New(logger, s.ts, query.ActionTimeout, query.LockTimeout)
// execute the command
err := vtctl.RunCommand(wr, query.Args)
// close the log channel, and wait for them all to be sent
close(logstream)
wg.Wait()
return err
}
// setAndStartWorker will set the current worker.
// We always log to both memory logger (for display on the web) and
// console logger (for records / display of command line worker).
func setAndStartWorker(wrk worker.Worker) (chan struct{}, error) {
currentWorkerMutex.Lock()
defer currentWorkerMutex.Unlock()
if currentWorker != nil {
return nil, fmt.Errorf("A worker is already in progress: %v", currentWorker)
}
currentWorker = wrk
currentMemoryLogger = logutil.NewMemoryLogger()
currentDone = make(chan struct{})
wr.SetLogger(logutil.NewTeeLogger(currentMemoryLogger, logutil.NewConsoleLogger()))
// one go function runs the worker, closes 'done' when done
go func() {
log.Infof("Starting worker...")
wrk.Run()
close(currentDone)
}()
return currentDone, nil
}
// Operate on restore tablet.
// Check that the SnapshotManifest is valid and the master has not changed.
// Shutdown mysqld.
// Load the snapshot from source tablet.
// Restart mysqld and replication.
// Put tablet into the replication graph as a spare.
// Should be called under RpcWrapLockAction.
func (agent *ActionAgent) Restore(ctx context.Context, args *actionnode.RestoreArgs, logger logutil.Logger) error {
// read our current tablet, verify its state
tablet, err := agent.TopoServer.GetTablet(agent.TabletAlias)
if err != nil {
return err
}
if args.WasReserved {
if tablet.Type != topo.TYPE_RESTORE {
return fmt.Errorf("expected restore type, not %v", tablet.Type)
}
} else {
if tablet.Type != topo.TYPE_IDLE {
return fmt.Errorf("expected idle type, not %v", tablet.Type)
}
}
// read the source tablet, compute args.SrcFilePath if default
sourceTablet, err := agent.TopoServer.GetTablet(args.SrcTabletAlias)
if err != nil {
return err
}
if strings.ToLower(args.SrcFilePath) == "default" {
args.SrcFilePath = path.Join(mysqlctl.SnapshotURLPath, mysqlctl.SnapshotManifestFile)
}
// read the parent tablet, verify its state
parentTablet, err := agent.TopoServer.GetTablet(args.ParentAlias)
if err != nil {
return err
}
if parentTablet.Type != topo.TYPE_MASTER && parentTablet.Type != topo.TYPE_SNAPSHOT_SOURCE {
return fmt.Errorf("restore expected master or snapshot_source parent: %v %v", parentTablet.Type, args.ParentAlias)
}
// read & unpack the manifest
sm := new(mysqlctl.SnapshotManifest)
if err := fetchAndParseJsonFile(sourceTablet.Addr(), args.SrcFilePath, sm); err != nil {
return err
}
if !args.WasReserved {
if err := agent.changeTypeToRestore(ctx, tablet, sourceTablet, parentTablet.Alias, sourceTablet.KeyRange); err != nil {
return err
}
}
// create the loggers: tee to console and source
l := logutil.NewTeeLogger(logutil.NewConsoleLogger(), logger)
// do the work
if err := agent.Mysqld.RestoreFromSnapshot(l, sm, args.FetchConcurrency, args.FetchRetryCount, args.DontWaitForSlaveStart, agent.hookExtraEnv()); err != nil {
log.Errorf("RestoreFromSnapshot failed (%v), scrapping", err)
if err := topotools.Scrap(agent.TopoServer, agent.TabletAlias, false); err != nil {
log.Errorf("Failed to Scrap after failed RestoreFromSnapshot: %v", err)
}
return err
}
// reload the schema
agent.ReloadSchema(ctx)
// change to TYPE_SPARE, we're done!
return topotools.ChangeType(agent.TopoServer, agent.TabletAlias, topo.TYPE_SPARE, nil, true)
}
// Snapshot takes a db snapshot
// Should be called under RpcWrapLockAction.
func (agent *ActionAgent) Snapshot(ctx context.Context, args *actionnode.SnapshotArgs, logger logutil.Logger) (*actionnode.SnapshotReply, error) {
// update our type to TYPE_BACKUP
tablet, err := agent.TopoServer.GetTablet(agent.TabletAlias)
if err != nil {
return nil, err
}
originalType := tablet.Type
// ForceMasterSnapshot: Normally a master is not a viable tablet
// to snapshot. However, there are degenerate cases where you need
// to override this, for instance the initial clone of a new master.
if tablet.Type == topo.TYPE_MASTER && args.ForceMasterSnapshot {
// In this case, we don't bother recomputing the serving graph.
// All queries will have to fail anyway.
log.Infof("force change type master -> backup")
// There is a legitimate reason to force in the case of a single
// master.
tablet.Tablet.Type = topo.TYPE_BACKUP
err = topo.UpdateTablet(ctx, agent.TopoServer, tablet)
} else {
err = topotools.ChangeType(agent.TopoServer, tablet.Alias, topo.TYPE_BACKUP, make(map[string]string), true /*runHooks*/)
}
if err != nil {
return nil, err
}
// let's update our internal state (stop query service and other things)
if err := agent.refreshTablet(ctx, "snapshotStart"); err != nil {
return nil, fmt.Errorf("failed to update state before snaphost: %v", err)
}
// create the loggers: tee to console and source
l := logutil.NewTeeLogger(logutil.NewConsoleLogger(), logger)
// now we can run the backup
filename, slaveStartRequired, readOnly, returnErr := agent.Mysqld.CreateSnapshot(l, tablet.DbName(), tablet.Addr(), false, args.Concurrency, args.ServerMode, agent.hookExtraEnv())
// and change our type to the appropriate value
newType := originalType
if returnErr != nil {
log.Errorf("snapshot failed, restoring tablet type back to %v: %v", newType, returnErr)
} else {
if args.ServerMode {
log.Infof("server mode specified, switching tablet to snapshot_source mode")
newType = topo.TYPE_SNAPSHOT_SOURCE
} else {
log.Infof("change type back after snapshot: %v", newType)
}
}
if tablet.Parent.Uid == topo.NO_TABLET && args.ForceMasterSnapshot && newType != topo.TYPE_SNAPSHOT_SOURCE {
log.Infof("force change type backup -> master: %v", tablet.Alias)
tablet.Tablet.Type = topo.TYPE_MASTER
err = topo.UpdateTablet(ctx, agent.TopoServer, tablet)
} else {
err = topotools.ChangeType(agent.TopoServer, tablet.Alias, newType, nil, true /*runHooks*/)
}
if err != nil {
// failure in changing the topology type is probably worse,
// so returning that (we logged the snapshot error anyway)
returnErr = err
}
// if anything failed, don't return anything
if returnErr != nil {
return nil, returnErr
}
// it all worked, return the required information
sr := &actionnode.SnapshotReply{
ManifestPath: filename,
SlaveStartRequired: slaveStartRequired,
ReadOnly: readOnly,
}
if tablet.Parent.Uid == topo.NO_TABLET {
// If this is a master, this will be the new parent.
// FIXME(msolomon) this doesn't work in hierarchical replication.
sr.ParentAlias = tablet.Alias
} else {
sr.ParentAlias = tablet.Parent
}
return sr, nil
}