// SnapshotSourceEnd restores the state of the server after a
// Snapshot(server_mode =true)
// Should be called under RpcWrapLockAction.
func (agent *ActionAgent) SnapshotSourceEnd(ctx context.Context, args *actionnode.SnapshotSourceEndArgs) error {
tablet, err := agent.TopoServer.GetTablet(agent.TabletAlias)
if err != nil {
return err
}
if tablet.Type != topo.TYPE_SNAPSHOT_SOURCE {
return fmt.Errorf("expected snapshot_source type, not %v", tablet.Type)
}
if err := agent.Mysqld.SnapshotSourceEnd(args.SlaveStartRequired, args.ReadOnly, true, agent.hookExtraEnv()); err != nil {
log.Errorf("SnapshotSourceEnd failed, leaving tablet type alone: %v", err)
return err
}
// change the type back
if args.OriginalType == topo.TYPE_MASTER {
// force the master update
tablet.Tablet.Type = topo.TYPE_MASTER
err = topo.UpdateTablet(ctx, agent.TopoServer, tablet)
} else {
err = topotools.ChangeType(agent.TopoServer, tablet.Alias, args.OriginalType, make(map[string]string), true /*runHooks*/)
}
return err
}
// ChangeTypeNoRebuild changes a tablet's type, and returns whether
// there's a shard that should be rebuilt, along with its cell,
// keyspace, and shard. If force is true, it will bypass the RPC action
// system and make the data change directly, and not run the remote
// hooks.
//
// Note we don't update the master record in the Shard here, as we
// can't ChangeType from and out of master anyway.
func (wr *Wrangler) ChangeTypeNoRebuild(tabletAlias topo.TabletAlias, tabletType topo.TabletType, force bool) (rebuildRequired bool, cell, keyspace, shard string, err error) {
// Load tablet to find keyspace and shard assignment.
// Don't load after the ChangeType which might have unassigned
// the tablet.
ti, err := wr.ts.GetTablet(tabletAlias)
if err != nil {
return false, "", "", "", err
}
if force {
if err := topotools.ChangeType(wr.ts, tabletAlias, tabletType, nil, false); err != nil {
return false, "", "", "", err
}
} else {
if err := wr.tmc.ChangeType(wr.ctx, ti, tabletType); err != nil {
return false, "", "", "", err
}
}
if !ti.Tablet.IsInServingGraph() {
// re-read the tablet, see if we become serving
ti, err = wr.ts.GetTablet(tabletAlias)
if err != nil {
return false, "", "", "", err
}
if !ti.Tablet.IsInServingGraph() {
return false, "", "", "", nil
}
}
return true, ti.Alias.Cell, ti.Keyspace, ti.Shard, nil
}
// terminateHealthChecks is called when we enter lame duck mode.
// We will clean up our state, and shut down query service.
// We only do something if we are in targetTabletType state, and then
// we just go to spare.
func (agent *ActionAgent) terminateHealthChecks(targetTabletType topo.TabletType) {
agent.actionMutex.Lock()
defer agent.actionMutex.Unlock()
log.Info("agent.terminateHealthChecks is starting")
// read the current tablet record
tablet := agent.Tablet()
if tablet.Type != targetTabletType {
log.Infof("Tablet in state %v, not changing it", tablet.Type)
return
}
// Change the Type to spare, update the health. Note we pass in a map
// that's not nil, meaning we will clear it.
if err := topotools.ChangeType(agent.TopoServer, tablet.Alias, topo.TYPE_SPARE, make(map[string]string), true /*runHooks*/); err != nil {
log.Infof("Error updating tablet record: %v", err)
return
}
// Rebuild the serving graph in our cell, only if we're dealing with
// a serving type
if err := agent.rebuildShardIfNeeded(tablet, targetTabletType); err != nil {
log.Warningf("rebuildShardIfNeeded failed (will still run post action callbacks, serving graph might be out of date): %v", err)
}
// We've already rebuilt the shard, which is the only reason we registered
// ourself as OnTermSync (synchronous). The rest can be done asynchronously.
go func() {
// Run the post action callbacks (let them shutdown the query service)
if err := agent.refreshTablet(context.TODO(), "terminatehealthcheck"); err != nil {
log.Warningf("refreshTablet failed: %v", err)
}
}()
}
// 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
}
// ChangeType changes the tablet type
// Should be called under RpcWrapLockAction.
func (agent *ActionAgent) ChangeType(ctx context.Context, tabletType topo.TabletType) error {
return topotools.ChangeType(agent.TopoServer, agent.TabletAlias, tabletType, nil, true /*runHooks*/)
}
// runHealthCheck takes the action mutex, runs the health check,
// and if we need to change our state, do it.
// If we are the master, we don't change our type, healthy or not.
// If we are not the master, we change to spare if not healthy,
// or to the passed in targetTabletType if healthy.
//
// Note we only update the topo record if we need to, that is if our type or
// health details changed.
func (agent *ActionAgent) runHealthCheck(targetTabletType topo.TabletType) {
agent.actionMutex.Lock()
defer agent.actionMutex.Unlock()
// read the current tablet record and tablet control
agent.mutex.Lock()
tablet := agent._tablet
tabletControl := agent._tabletControl
agent.mutex.Unlock()
// figure out if we should be running the query service
shouldQueryServiceBeRunning := false
var blacklistedTables []string
if topo.IsRunningQueryService(targetTabletType) && agent.BinlogPlayerMap.size() == 0 {
shouldQueryServiceBeRunning = true
if tabletControl != nil {
blacklistedTables = tabletControl.BlacklistedTables
if tabletControl.DisableQueryService {
shouldQueryServiceBeRunning = false
}
}
}
// run the health check
typeForHealthCheck := targetTabletType
if tablet.Type == topo.TYPE_MASTER {
typeForHealthCheck = topo.TYPE_MASTER
}
health, err := health.Run(typeForHealthCheck, shouldQueryServiceBeRunning)
// Figure out if we should be running QueryService. If we should,
// and we aren't, try to start it (even if we're not healthy,
// the reason we might not be healthy is the query service not running!)
if shouldQueryServiceBeRunning {
if err == nil {
// we remember this new possible error
err = agent.allowQueries(tablet.Tablet, blacklistedTables)
} else {
// we ignore the error
agent.allowQueries(tablet.Tablet, blacklistedTables)
}
}
// save the health record
record := &HealthRecord{
Error: err,
Result: health,
Time: time.Now(),
}
agent.History.Add(record)
// try to figure out the mysql port if we don't have it yet
if _, ok := tablet.Portmap["mysql"]; !ok {
// we don't know the port, try to get it from mysqld
mysqlPort, err := agent.Mysqld.GetMysqlPort()
if err != nil {
// Don't log if we're already in a waiting-for-mysql state.
agent.mutex.Lock()
if !agent._waitingForMysql {
log.Warningf("Can't get mysql port, won't populate Tablet record in topology (will retry silently at healthcheck interval %v): %v", *healthCheckInterval, err)
agent._waitingForMysql = true
}
agent.mutex.Unlock()
} else {
log.Infof("Updating tablet mysql port to %v", mysqlPort)
if err := agent.TopoServer.UpdateTabletFields(tablet.Alias, func(tablet *topo.Tablet) error {
tablet.Portmap["mysql"] = mysqlPort
return nil
}); err != nil {
log.Infof("Error updating mysql port in tablet record: %v", err)
return
}
// save the port so we don't update it again next time
// we do the health check.
agent.mutex.Lock()
agent._tablet.Portmap["mysql"] = mysqlPort
agent._waitingForMysql = false
agent.mutex.Unlock()
}
}
// remember our health status
agent.mutex.Lock()
agent._healthy = err
agent.mutex.Unlock()
// Update our topo.Server state, start with no change
newTabletType := tablet.Type
if err != nil {
// The tablet is not healthy, let's see what we need to do
if tablet.Type != targetTabletType {
if tablet.Type != topo.TYPE_SPARE {
// we only log if we're not in spare,
// as the spare state is normal for a
// failed health check.
log.Infof("Tablet not healthy and in state %v, not changing it: %v", tablet.Type, err)
}
return
}
// Note that if the query service is running, we may
// need to stop it. The post-action callback will do
// it, and it will be done after we change our state,
// so it's the right order, let it do it.
log.Infof("Tablet not healthy, converting it from %v to spare: %v", targetTabletType, err)
newTabletType = topo.TYPE_SPARE
} else {
// We are healthy, maybe with health, see if we need
// to update the record. We only change from spare to
// our target type.
if tablet.Type == topo.TYPE_SPARE {
newTabletType = targetTabletType
}
if tablet.Type == newTabletType && tablet.IsHealthEqual(health) {
// no change in health, not logging anything,
// and we're done
return
}
// we need to update our state
log.Infof("Updating tablet record as healthy type %v -> %v with health details %v -> %v", tablet.Type, newTabletType, tablet.Health, health)
agent.lastHealthMapCount.Set(int64(len(health)))
}
// Change the Type, update the health. Note we pass in a map
// that's not nil, meaning if it's empty, we will clear it.
if err := topotools.ChangeType(agent.TopoServer, tablet.Alias, newTabletType, health, true /*runHooks*/); err != nil {
log.Infof("Error updating tablet record: %v", err)
return
}
// Rebuild the serving graph in our cell, only if we're dealing with
// a serving type
if err := agent.rebuildShardIfNeeded(tablet, targetTabletType); err != nil {
log.Warningf("rebuildShardIfNeeded failed (will still run post action callbacks, serving graph might be out of date): %v", err)
}
// run the post action callbacks, not much we can do with returned error
if err := agent.refreshTablet(context.TODO(), "healthcheck"); err != nil {
log.Warningf("refreshTablet failed: %v", err)
}
}