Golang servenv.OnTerm函数代码示例

func main() {
	dbconfigs.RegisterFlags()
	flag.Parse()
	servenv.Init()

	dbConfigs, err := dbconfigs.Init("")
	if err != nil {
		log.Fatalf("Cannot initialize App dbconfig: %v", err)
	}
	if *enableRowcache {
		dbConfigs.App.EnableRowcache = true
		if *enableInvalidator {
			dbConfigs.App.EnableInvalidator = true
		}
	}
	mycnf := &mysqlctl.Mycnf{BinLogPath: *binlogPath}
	mysqld := mysqlctl.NewMysqld(mycnf, &dbConfigs.Dba, &dbConfigs.Repl)

	unmarshalFile(*overridesFile, &schemaOverrides)
	data, _ := json.MarshalIndent(schemaOverrides, "", "  ")
	log.Infof("schemaOverrides: %s\n", data)

	ts.InitQueryService()

	ts.AllowQueries(&dbConfigs.App, schemaOverrides, ts.LoadCustomRules(), mysqld)

	log.Infof("starting vtocc %v", *servenv.Port)
	servenv.OnTerm(func() {
		ts.DisallowQueries()
	})
	servenv.Run()
}

func main() {
	defer exit.Recover()
	defer logutil.Flush()

	dbconfigs.RegisterFlags()
	flag.Parse()

	mycnf := mysqlctl.NewMycnf(uint32(*tabletUid), *mysqlPort)
	if *mysqlSocket != "" {
		mycnf.SocketFile = *mysqlSocket
	}

	dbcfgs, err := dbconfigs.Init(mycnf.SocketFile)
	if err != nil {
		log.Errorf("%v", err)
		exit.Return(255)
	}
	mysqld = mysqlctl.NewMysqld("Dba", mycnf, &dbcfgs.Dba, &dbcfgs.Repl)

	// Register OnTerm handler before mysqld starts, so we get notified if mysqld
	// dies on its own without us (or our RPC client) telling it to.
	mysqldTerminated := make(chan struct{})
	mysqld.OnTerm(func() {
		close(mysqldTerminated)
	})

	// Start or Init mysqld as needed.
	if _, err = os.Stat(mycnf.DataDir); os.IsNotExist(err) {
		log.Infof("mysql data dir (%s) doesn't exist, initializing", mycnf.DataDir)
		mysqld.Init(*waitTime, *bootstrapArchive, *skipSchema)
	} else {
		log.Infof("mysql data dir (%s) already exists, starting without init", mycnf.DataDir)
		mysqld.Start(*waitTime)
	}

	servenv.Init()
	defer servenv.Close()

	// Take mysqld down with us on SIGTERM before entering lame duck.
	servenv.OnTerm(func() {
		log.Infof("mysqlctl received SIGTERM, shutting down mysqld first")
		mysqld.Shutdown(false, 0)
	})

	// Start RPC server and wait for SIGTERM.
	mysqlctldTerminated := make(chan struct{})
	go func() {
		servenv.RunDefault()
		close(mysqlctldTerminated)
	}()

	select {
	case <-mysqldTerminated:
		log.Infof("mysqld shut down on its own, exiting mysqlctld")
	case <-mysqlctldTerminated:
		log.Infof("mysqlctld shut down gracefully")
	}
}

func main() {
	defer exit.Recover()

	// flag parsing
	flags := dbconfigs.AppConfig | dbconfigs.DbaConfig |
		dbconfigs.FilteredConfig | dbconfigs.ReplConfig
	dbconfigs.RegisterFlags(flags)
	mysqlctl.RegisterFlags()
	flag.Parse()
	if len(flag.Args()) > 0 {
		flag.Usage()
		log.Errorf("vtcombo doesn't take any positional arguments")
		exit.Return(1)
	}

	// register topo server
	topo.RegisterServer("fakezk", zktopo.NewServer(fakezk.NewConn()))
	ts := topo.GetServerByName("fakezk")

	servenv.Init()

	// database configs
	mycnf, err := mysqlctl.NewMycnfFromFlags(0)
	if err != nil {
		log.Errorf("mycnf read failed: %v", err)
		exit.Return(1)
	}
	dbcfgs, err := dbconfigs.Init(mycnf.SocketFile, flags)
	if err != nil {
		log.Warning(err)
	}
	mysqld := mysqlctl.NewMysqld("Dba", "App", mycnf, &dbcfgs.Dba, &dbcfgs.App.ConnParams, &dbcfgs.Repl)

	// tablets configuration and init
	binlog.RegisterUpdateStreamService(mycnf)
	initTabletMap(ts, *topology, mysqld, dbcfgs, mycnf)

	// vtgate configuration and init
	resilientSrvTopoServer := vtgate.NewResilientSrvTopoServer(ts, "ResilientSrvTopoServer")
	healthCheck := discovery.NewHealthCheck(30*time.Second /*connTimeoutTotal*/, 1*time.Millisecond /*retryDelay*/)
	vtgate.Init(healthCheck, ts, resilientSrvTopoServer, nil /*schema*/, cell, 1*time.Millisecond /*retryDelay*/, 2 /*retryCount*/, 30*time.Second /*connTimeoutTotal*/, 10*time.Second /*connTimeoutPerConn*/, 365*24*time.Hour /*connLife*/, 0 /*maxInFlight*/, "" /*testGateway*/)

	servenv.OnTerm(func() {
		// FIXME(alainjobart) stop vtgate, all tablets
		//		qsc.DisallowQueries()
		//		agent.Stop()
	})
	servenv.OnClose(func() {
		// We will still use the topo server during lameduck period
		// to update our state, so closing it in OnClose()
		topo.CloseServers()
	})
	servenv.RunDefault()
}

func main() {
	dbconfigs.RegisterFlags()
	mysqlctl.RegisterFlags()
	flag.Parse()
	if len(flag.Args()) > 0 {
		flag.Usage()
		log.Fatalf("vttablet doesn't take any positional arguments")
	}

	servenv.Init()

	if *tabletPath == "" {
		log.Fatalf("tabletPath required")
	}
	tabletAlias := tabletParamToTabletAlias(*tabletPath)

	mycnf, err := mysqlctl.NewMycnfFromFlags(tabletAlias.Uid)
	if err != nil {
		log.Fatalf("mycnf read failed: %v", err)
	}

	dbcfgs, err := dbconfigs.Init(mycnf.SocketFile)
	if err != nil {
		log.Warning(err)
	}
	dbcfgs.App.EnableRowcache = *enableRowcache

	if *tableAclConfig != "" {
		tableacl.Init(*tableAclConfig)
	}
	tabletserver.InitQueryService()
	binlog.RegisterUpdateStreamService(mycnf)

	// Depends on both query and updateStream.
	agent, err = tabletmanager.NewActionAgent(tabletAlias, dbcfgs, mycnf, *servenv.Port, *servenv.SecurePort, *overridesFile)
	if err != nil {
		log.Fatal(err)
	}

	tabletmanager.HttpHandleSnapshots(mycnf, tabletAlias.Uid)
	servenv.OnTerm(func() {
		tabletserver.DisallowQueries()
		binlog.DisableUpdateStreamService()
		agent.Stop()
	})
	servenv.OnClose(func() {
		// We will still use the topo server during lameduck period
		// to update our state, so closing it in OnClose()
		topo.CloseServers()
	})
	servenv.RunDefault()
}

func main() {
	dbconfigs.RegisterFlags()
	flag.Parse()

	servenv.Init()

	if *tabletPath == "" {
		log.Fatalf("tabletPath required")
	}
	tabletAlias := vttablet.TabletParamToTabletAlias(*tabletPath)

	if *mycnfFile == "" {
		*mycnfFile = mysqlctl.MycnfFile(tabletAlias.Uid)
	}

	mycnf, err := mysqlctl.ReadMycnf(*mycnfFile)
	if err != nil {
		log.Fatalf("mycnf read failed: %v", err)
	}

	dbcfgs, err := dbconfigs.Init(mycnf.SocketFile)
	if err != nil {
		log.Warning(err)
	}
	dbcfgs.App.EnableRowcache = *enableRowcache

	ts.InitQueryService()
	binlog.RegisterUpdateStreamService(mycnf)

	// Depends on both query and updateStream.
	agent, err = vttablet.InitAgent(tabletAlias, dbcfgs, mycnf, *servenv.Port, *servenv.SecurePort, *overridesFile)
	if err != nil {
		log.Fatal(err)
	}

	vttablet.HttpHandleSnapshots(mycnf, tabletAlias.Uid)
	servenv.OnTerm(func() {
		ts.DisallowQueries()
		binlog.DisableUpdateStreamService()
		topo.CloseServers()
		agent.Stop()
	})
	servenv.Run()
}

func main() {
	dbconfigs.RegisterFlags()
	flag.Parse()
	if len(flag.Args()) > 0 {
		flag.Usage()
		log.Fatalf("vtocc doesn't take any positional arguments")
	}
	servenv.Init()

	dbConfigs, err := dbconfigs.Init("")
	if err != nil {
		log.Fatalf("Cannot initialize App dbconfig: %v", err)
	}
	if *enableRowcache {
		dbConfigs.App.EnableRowcache = true
		if *enableInvalidator {
			dbConfigs.App.EnableInvalidator = true
		}
	}
	mycnf := &mysqlctl.Mycnf{BinLogPath: *binlogPath}
	mysqld := mysqlctl.NewMysqld("Dba", mycnf, &dbConfigs.Dba, &dbConfigs.Repl)

	unmarshalFile(*overridesFile, &schemaOverrides)
	data, _ := json.MarshalIndent(schemaOverrides, "", "  ")
	log.Infof("schemaOverrides: %s\n", data)

	if *tableAclConfig != "" {
		tableacl.Init(*tableAclConfig)
	}
	tabletserver.InitQueryService()

	err = tabletserver.AllowQueries(&dbConfigs.App, schemaOverrides, tabletserver.LoadCustomRules(), mysqld, true)
	if err != nil {
		return
	}

	log.Infof("starting vtocc %v", *servenv.Port)
	servenv.OnTerm(func() {
		tabletserver.DisallowQueries()
		mysqld.Close()
	})
	servenv.RunDefault()
}

func (agent *ActionAgent) initHeathCheck() {
	if !agent.IsRunningHealthCheck() {
		log.Infof("No target_tablet_type specified, disabling any health check")
		return
	}

	log.Infof("Starting periodic health check every %v with target_tablet_type=%v", *healthCheckInterval, *targetTabletType)
	t := timer.NewTimer(*healthCheckInterval)
	servenv.OnTerm(func() {
		// When we enter lameduck mode, we want to not call
		// the health check any more. After this returns, we
		// are guaranteed to not call it.
		log.Info("Stopping periodic health check timer")
		t.Stop()

		// Now we can finish up and force ourselves to not healthy.
		agent.terminateHealthChecks(topo.TabletType(*targetTabletType))
	})
	t.Start(func() {
		agent.runHealthCheck(topo.TabletType(*targetTabletType))
	})
}

func main() {
	defer exit.Recover()
	defer logutil.Flush()

	dbconfigFlags := dbconfigs.AppConfig | dbconfigs.DbaConfig |
		dbconfigs.FilteredConfig | dbconfigs.ReplConfig
	dbconfigs.RegisterFlags(dbconfigFlags)
	flag.Parse()

	// We'll register this OnTerm handler before mysqld starts, so we get notified
	// if mysqld dies on its own without us (or our RPC client) telling it to.
	mysqldTerminated := make(chan struct{})
	onTermFunc := func() {
		close(mysqldTerminated)
	}

	// Start or Init mysqld as needed.
	ctx, cancel := context.WithTimeout(context.Background(), *waitTime)
	tabletDir := mysqlctl.TabletDir(uint32(*tabletUID))
	if _, statErr := os.Stat(tabletDir); os.IsNotExist(statErr) {
		// Generate my.cnf from scratch and use it to find mysqld.
		log.Infof("tablet dir (%s) doesn't exist, initializing", tabletDir)

		var err error
		mysqld, err = mysqlctl.CreateMysqld(uint32(*tabletUID), *mysqlSocket, int32(*mysqlPort), dbconfigFlags)
		if err != nil {
			log.Errorf("failed to initialize mysql config: %v", err)
			exit.Return(1)
		}
		mysqld.OnTerm(onTermFunc)

		if err := mysqld.Init(ctx, *initDBSQLFile); err != nil {
			log.Errorf("failed to initialize mysql data dir and start mysqld: %v", err)
			exit.Return(1)
		}
	} else {
		// There ought to be an existing my.cnf, so use it to find mysqld.
		log.Infof("tablet dir (%s) already exists, starting without init", tabletDir)

		var err error
		mysqld, err = mysqlctl.OpenMysqld(uint32(*tabletUID), dbconfigFlags)
		if err != nil {
			log.Errorf("failed to find mysql config: %v", err)
			exit.Return(1)
		}
		mysqld.OnTerm(onTermFunc)

		if err := mysqld.Start(ctx); err != nil {
			log.Errorf("failed to start mysqld: %v", err)
			exit.Return(1)
		}
	}
	cancel()

	servenv.Init()
	defer servenv.Close()

	// Take mysqld down with us on SIGTERM before entering lame duck.
	servenv.OnTerm(func() {
		log.Infof("mysqlctl received SIGTERM, shutting down mysqld first")
		ctx := context.Background()
		mysqld.Shutdown(ctx, false)
	})

	// Start RPC server and wait for SIGTERM.
	mysqlctldTerminated := make(chan struct{})
	go func() {
		servenv.RunDefault()
		close(mysqlctldTerminated)
	}()

	select {
	case <-mysqldTerminated:
		log.Infof("mysqld shut down on its own, exiting mysqlctld")
	case <-mysqlctldTerminated:
		log.Infof("mysqlctld shut down gracefully")
	}
}

func main() {
	defer exit.Recover()

	flags := dbconfigs.AppConfig | dbconfigs.DbaConfig |
		dbconfigs.FilteredConfig | dbconfigs.ReplConfig
	dbconfigs.RegisterFlags(flags)
	mysqlctl.RegisterFlags()
	flag.Parse()
	tabletserver.Init()
	if len(flag.Args()) > 0 {
		flag.Usage()
		log.Errorf("vttablet doesn't take any positional arguments")
		exit.Return(1)
	}

	servenv.Init()

	if *tabletPath == "" {
		log.Errorf("tabletPath required")
		exit.Return(1)
	}
	tabletAlias, err := topoproto.ParseTabletAlias(*tabletPath)
	if err != nil {
		log.Error(err)
		exit.Return(1)
	}

	mycnf, err := mysqlctl.NewMycnfFromFlags(tabletAlias.Uid)
	if err != nil {
		log.Errorf("mycnf read failed: %v", err)
		exit.Return(1)
	}

	dbcfgs, err := dbconfigs.Init(mycnf.SocketFile, flags)
	if err != nil {
		log.Warning(err)
	}
	dbcfgs.App.EnableRowcache = *enableRowcache

	// creates and registers the query service
	qsc := tabletserver.NewServer()
	qsc.Register()
	binlog.RegisterUpdateStreamService(mycnf)

	if *tableAclConfig != "" {
		tableacl.Register("simpleacl", &simpleacl.Factory{})
		tableacl.Init(
			*tableAclConfig,
			func() {
				qsc.ClearQueryPlanCache()
			},
		)
	} else if *enforceTableACLConfig {
		log.Error("table acl config has to be specified with table-acl-config flag because enforce-tableacl-config is set.")
		exit.Return(1)
	}

	// Create mysqld and register the health reporter (needs to be done
	// before initializing the agent, so the initial health check
	// done by the agent has the right reporter)
	mysqld := mysqlctl.NewMysqld("Dba", "App", mycnf, &dbcfgs.Dba, &dbcfgs.App.ConnParams, &dbcfgs.Repl)
	registerHealthReporter(mysqld)

	// Depends on both query and updateStream.
	gRPCPort := int32(0)
	if servenv.GRPCPort != nil {
		gRPCPort = int32(*servenv.GRPCPort)
	}
	agent, err = tabletmanager.NewActionAgent(context.Background(), mysqld, qsc, tabletAlias, dbcfgs, mycnf, int32(*servenv.Port), gRPCPort, *overridesFile, *lockTimeout)
	if err != nil {
		log.Error(err)
		exit.Return(1)
	}

	servenv.OnRun(func() {
		addStatusParts(qsc)
	})
	servenv.OnTerm(func() {
		qsc.StopService()
		binlog.DisableUpdateStreamService()
		agent.Stop()
	})
	servenv.OnClose(func() {
		// We will still use the topo server during lameduck period
		// to update our state, so closing it in OnClose()
		topo.CloseServers()
	})
	servenv.RunDefault()
}

func init() {
	tabletserver.QueryServiceControlRegisterFunctions = append(tabletserver.QueryServiceControlRegisterFunctions, ActivateZkCustomRules)
	servenv.OnTerm(zkCustomRule.Close)
}

// Start validates and updates the topology records for the tablet, and performs
// the initial state change callback to start tablet services.
// If initUpdateStream is set, update stream service will also be registered.
func (agent *ActionAgent) Start(ctx context.Context, mysqlPort, vtPort, gRPCPort int32, initUpdateStream bool) error {
	var err error
	if _, err = agent.updateTabletFromTopo(ctx); err != nil {
		return err
	}

	// find our hostname as fully qualified, and IP
	hostname := *tabletHostname
	if hostname == "" {
		hostname, err = netutil.FullyQualifiedHostname()
		if err != nil {
			return err
		}
	}
	ipAddrs, err := net.LookupHost(hostname)
	if err != nil {
		return err
	}
	ipAddr := ipAddrs[0]

	// Update bind addr for mysql and query service in the tablet node.
	f := func(tablet *topodatapb.Tablet) error {
		tablet.Hostname = hostname
		tablet.Ip = ipAddr
		if tablet.PortMap == nil {
			tablet.PortMap = make(map[string]int32)
		}
		if mysqlPort != 0 {
			// only overwrite mysql port if we know it, otherwise
			// leave it as is.
			tablet.PortMap["mysql"] = mysqlPort
		}
		if vtPort != 0 {
			tablet.PortMap["vt"] = vtPort
		} else {
			delete(tablet.PortMap, "vt")
		}
		delete(tablet.PortMap, "vts")
		if gRPCPort != 0 {
			tablet.PortMap["grpc"] = gRPCPort
		} else {
			delete(tablet.PortMap, "grpc")
		}
		return nil
	}
	if _, err := agent.TopoServer.UpdateTabletFields(ctx, agent.Tablet().Alias, f); err != nil {
		return err
	}

	// Reread to get the changes we just made
	tablet, err := agent.updateTabletFromTopo(ctx)
	if err != nil {
		return err
	}

	// Save the original tablet record as it is now (at startup).
	agent.initialTablet = proto.Clone(tablet).(*topodatapb.Tablet)

	if err = agent.verifyTopology(ctx); err != nil {
		return err
	}

	if err = agent.verifyServingAddrs(ctx); err != nil {
		return err
	}

	// get and fix the dbname if necessary
	if !agent.DBConfigs.IsZero() {
		// Only for real instances
		// Update our DB config to match the info we have in the tablet
		if agent.DBConfigs.App.DbName == "" {
			agent.DBConfigs.App.DbName = topoproto.TabletDbName(tablet)
		}
		if agent.DBConfigs.Filtered.DbName == "" {
			agent.DBConfigs.Filtered.DbName = topoproto.TabletDbName(tablet)
		}
		agent.DBConfigs.App.Keyspace = tablet.Keyspace
		agent.DBConfigs.App.Shard = tablet.Shard
	}

	// create and register the RPC services from UpdateStream
	// (it needs the dbname, so it has to be delayed up to here,
	// but it has to be before updateState below that may use it)
	if initUpdateStream {
		us := binlog.NewUpdateStream(agent.MysqlDaemon, agent.DBConfigs.App.DbName)
		us.RegisterService()
		agent.UpdateStream = us
	}
	servenv.OnTerm(func() {
		// Disable UpdateStream (if any) upon entering lameduck.
		// We do this regardless of initUpdateStream, since agent.UpdateStream
		// may have been set from elsewhere.
		if agent.UpdateStream != nil {
			agent.UpdateStream.Disable()
		}
	})

//.........这里部分代码省略.........

func main() {
	defer exit.Recover()
	defer logutil.Flush()

	flags := dbconfigs.AppConfig | dbconfigs.DbaConfig |
		dbconfigs.FilteredConfig | dbconfigs.ReplConfig
	dbconfigs.RegisterFlags(flags)
	flag.Parse()

	mycnf := mysqlctl.NewMycnf(uint32(*tabletUID), int32(*mysqlPort))
	if *mysqlSocket != "" {
		mycnf.SocketFile = *mysqlSocket
	}

	dbcfgs, err := dbconfigs.Init(mycnf.SocketFile, flags)
	if err != nil {
		log.Errorf("%v", err)
		exit.Return(255)
	}
	mysqld = mysqlctl.NewMysqld("Dba", "App", mycnf, &dbcfgs.Dba, &dbcfgs.App.ConnParams, &dbcfgs.Repl)

	// Register OnTerm handler before mysqld starts, so we get notified if mysqld
	// dies on its own without us (or our RPC client) telling it to.
	mysqldTerminated := make(chan struct{})
	mysqld.OnTerm(func() {
		close(mysqldTerminated)
	})

	// Start or Init mysqld as needed.
	ctx, cancel := context.WithTimeout(context.Background(), *waitTime)
	if _, err = os.Stat(mycnf.DataDir); os.IsNotExist(err) {
		log.Infof("mysql data dir (%s) doesn't exist, initializing", mycnf.DataDir)
		mysqld.Init(ctx, *initDBSQLFile)
	} else {
		log.Infof("mysql data dir (%s) already exists, starting without init", mycnf.DataDir)
		mysqld.Start(ctx)
	}
	cancel()

	servenv.Init()
	defer servenv.Close()

	// Take mysqld down with us on SIGTERM before entering lame duck.
	servenv.OnTerm(func() {
		log.Infof("mysqlctl received SIGTERM, shutting down mysqld first")
		ctx := context.Background()
		mysqld.Shutdown(ctx, false)
	})

	// Start RPC server and wait for SIGTERM.
	mysqlctldTerminated := make(chan struct{})
	go func() {
		servenv.RunDefault()
		close(mysqlctldTerminated)
	}()

	select {
	case <-mysqldTerminated:
		log.Infof("mysqld shut down on its own, exiting mysqlctld")
	case <-mysqlctldTerminated:
		log.Infof("mysqlctld shut down gracefully")
	}
}

func main() {
	defer exit.Recover()

	// flag parsing
	flags := dbconfigs.AppConfig | dbconfigs.DbaConfig |
		dbconfigs.FilteredConfig | dbconfigs.ReplConfig
	dbconfigs.RegisterFlags(flags)
	mysqlctl.RegisterFlags()
	flag.Parse()
	if len(flag.Args()) > 0 {
		flag.Usage()
		log.Errorf("vtcombo doesn't take any positional arguments")
		exit.Return(1)
	}

	// register topo server
	zkconn := fakezk.NewConn()
	topo.RegisterServer("fakezk", zktopo.NewServer(zkconn))
	ts = topo.GetServerByName("fakezk")

	servenv.Init()
	tabletserver.Init()

	// database configs
	mycnf, err := mysqlctl.NewMycnfFromFlags(0)
	if err != nil {
		log.Errorf("mycnf read failed: %v", err)
		exit.Return(1)
	}
	dbcfgs, err := dbconfigs.Init(mycnf.SocketFile, flags)
	if err != nil {
		log.Warning(err)
	}
	mysqld := mysqlctl.NewMysqld("Dba", "App", mycnf, &dbcfgs.Dba, &dbcfgs.App.ConnParams, &dbcfgs.Repl)
	servenv.OnClose(mysqld.Close)

	// tablets configuration and init
	initTabletMap(ts, *topology, mysqld, dbcfgs, mycnf)

	// vschema
	var schema *planbuilder.Schema
	if *vschema != "" {
		schema, err = planbuilder.LoadFile(*vschema)
		if err != nil {
			log.Error(err)
			exit.Return(1)
		}
		log.Infof("v3 is enabled: loaded schema from file")
	}

	// vtgate configuration and init
	resilientSrvTopoServer := vtgate.NewResilientSrvTopoServer(ts, "ResilientSrvTopoServer")
	healthCheck := discovery.NewHealthCheck(30*time.Second /*connTimeoutTotal*/, 1*time.Millisecond /*retryDelay*/, 1*time.Minute /*healthCheckTimeout*/)
	tabletTypesToWait := []topodatapb.TabletType{
		topodatapb.TabletType_MASTER,
		topodatapb.TabletType_REPLICA,
		topodatapb.TabletType_RDONLY,
	}
	vtgate.Init(healthCheck, ts, resilientSrvTopoServer, schema, cell, 1*time.Millisecond /*retryDelay*/, 2 /*retryCount*/, 30*time.Second /*connTimeoutTotal*/, 10*time.Second /*connTimeoutPerConn*/, 365*24*time.Hour /*connLife*/, tabletTypesToWait, 0 /*maxInFlight*/, "" /*testGateway*/)

	// vtctld configuration and init
	vtctld.InitVtctld(ts)
	vtctld.HandleExplorer("zk", zktopo.NewZkExplorer(zkconn))

	servenv.OnTerm(func() {
		// FIXME(alainjobart): stop vtgate
	})
	servenv.OnClose(func() {
		log.Infof("Total count of new connections to MySQL: %v", expvar.Get("mysql-new-connection-count"))
		// We will still use the topo server during lameduck period
		// to update our state, so closing it in OnClose()
		topo.CloseServers()
	})
	servenv.RunDefault()
}

// NewActionAgent creates a new ActionAgent and registers all the
// associated services.
//
// batchCtx is the context that the agent will use for any background tasks
// it spawns.
func NewActionAgent(
	batchCtx context.Context,
	mysqld mysqlctl.MysqlDaemon,
	queryServiceControl tabletserver.Controller,
	tabletAlias *topodatapb.TabletAlias,
	dbcfgs dbconfigs.DBConfigs,
	mycnf *mysqlctl.Mycnf,
	port, gRPCPort int32,
	overridesFile string,
) (agent *ActionAgent, err error) {
	schemaOverrides := loadSchemaOverrides(overridesFile)

	topoServer := topo.GetServer()

	agent = &ActionAgent{
		QueryServiceControl: queryServiceControl,
		HealthReporter:      health.DefaultAggregator,
		batchCtx:            batchCtx,
		TopoServer:          topoServer,
		TabletAlias:         tabletAlias,
		MysqlDaemon:         mysqld,
		DBConfigs:           dbcfgs,
		SchemaOverrides:     schemaOverrides,
		History:             history.New(historyLength),
		lastHealthMapCount:  stats.NewInt("LastHealthMapCount"),
		_healthy:            fmt.Errorf("healthcheck not run yet"),
	}
	agent.registerQueryRuleSources()

	// try to initialize the tablet if we have to
	if err := agent.InitTablet(port, gRPCPort); err != nil {
		return nil, fmt.Errorf("agent.InitTablet failed: %v", err)
	}

	// Publish and set the TargetTabletType. Not a global var
	// since it should never be changed.
	statsTabletType := stats.NewString("TargetTabletType")
	statsTabletType.Set(*targetTabletType)

	// Create the TabletType stats
	agent.exportStats = true
	agent.statsTabletType = stats.NewString("TabletType")

	// Start the binlog player services, not playing at start.
	agent.BinlogPlayerMap = NewBinlogPlayerMap(topoServer, mysqld, func() binlogplayer.VtClient {
		return binlogplayer.NewDbClient(&agent.DBConfigs.Filtered)
	})
	// Stop all binlog players upon entering lameduck.
	servenv.OnTerm(agent.BinlogPlayerMap.StopAllPlayersAndReset)
	RegisterBinlogPlayerMap(agent.BinlogPlayerMap)

	// try to figure out the mysql port
	mysqlPort := mycnf.MysqlPort
	if mysqlPort == 0 {
		// we don't know the port, try to get it from mysqld
		var err error
		mysqlPort, err = mysqld.GetMysqlPort()
		if err != nil {
			log.Warningf("Cannot get current mysql port, will use 0 for now: %v", err)
		}
	}

	// Start will get the tablet info, and update our state from it
	if err := agent.Start(batchCtx, int32(mysqlPort), port, gRPCPort, true); err != nil {
		return nil, err
	}

	// register the RPC services from the agent
	agent.registerQueryService()

	// two cases then:
	// - restoreFromBackup is set: we restore, then initHealthCheck, all
	//   in the background
	// - restoreFromBackup is not set: we initHealthCheck right away
	if *restoreFromBackup {
		go func() {
			// restoreFromBackup wil just be a regular action
			// (same as if it was triggered remotely)
			if err := agent.RestoreFromBackup(batchCtx); err != nil {
				println(fmt.Sprintf("RestoreFromBackup failed: %v", err))
				log.Fatalf("RestoreFromBackup failed: %v", err)
			}

			// after the restore is done, start health check
			agent.initHealthCheck()
		}()
	} else {
		// synchronously start health check if needed
		agent.initHealthCheck()
	}

	return agent, nil
}

func main() {
	defer exit.Recover()

	// flag parsing
	flags := dbconfigs.AppConfig | dbconfigs.DbaConfig |
		dbconfigs.FilteredConfig | dbconfigs.ReplConfig
	dbconfigs.RegisterFlags(flags)
	mysqlctl.RegisterFlags()
	flag.Parse()
	if len(flag.Args()) > 0 {
		flag.Usage()
		log.Errorf("vtcombo doesn't take any positional arguments")
		exit.Return(1)
	}

	// set discoverygateway flag to default value
	flag.Set("cells_to_watch", cell)

	// register topo server
	zkconn := fakezk.NewConn()
	topo.RegisterServer("fakezk", zktopo.NewServer(zkconn))
	ts = topo.GetServerByName("fakezk")

	servenv.Init()
	tabletserver.Init()

	// database configs
	mycnf, err := mysqlctl.NewMycnfFromFlags(0)
	if err != nil {
		log.Errorf("mycnf read failed: %v", err)
		exit.Return(1)
	}
	dbcfgs, err := dbconfigs.Init(mycnf.SocketFile, flags)
	if err != nil {
		log.Warning(err)
	}
	mysqld := mysqlctl.NewMysqld("Dba", "App", mycnf, &dbcfgs.Dba, &dbcfgs.App.ConnParams, &dbcfgs.Repl)
	servenv.OnClose(mysqld.Close)

	// tablets configuration and init
	if err := initTabletMap(ts, *protoTopo, mysqld, dbcfgs, *schemaDir, mycnf); err != nil {
		log.Errorf("initTabletMapProto failed: %v", err)
		exit.Return(1)
	}

	// vtgate configuration and init
	resilientSrvTopoServer := vtgate.NewResilientSrvTopoServer(ts, "ResilientSrvTopoServer")
	healthCheck := discovery.NewHealthCheck(30*time.Second /*connTimeoutTotal*/, 1*time.Millisecond /*retryDelay*/, 1*time.Hour /*healthCheckTimeout*/)
	tabletTypesToWait := []topodatapb.TabletType{
		topodatapb.TabletType_MASTER,
		topodatapb.TabletType_REPLICA,
		topodatapb.TabletType_RDONLY,
	}
	vtgate.Init(context.Background(), healthCheck, ts, resilientSrvTopoServer, cell, 2 /*retryCount*/, tabletTypesToWait)

	// vtctld configuration and init
	vtctld.InitVtctld(ts)
	vtctld.HandleExplorer("zk", zktopo.NewZkExplorer(zkconn))

	servenv.OnTerm(func() {
		// FIXME(alainjobart): stop vtgate
	})
	servenv.OnClose(func() {
		// We will still use the topo server during lameduck period
		// to update our state, so closing it in OnClose()
		topo.CloseServers()
	})
	servenv.RunDefault()
}