func (g *GrafanaServerImpl) Shutdown(code int, reason string) {
	g.log.Info("Shutdown started", "code", code, "reason", reason)

	g.shutdownFn()
	err := g.childRoutines.Wait()

	g.log.Info("Shutdown completed", "reason", err)
	log.Close()
	os.Exit(code)
}

func listenToSystemSignels() {
	signalChan := make(chan os.Signal, 1)
	code := 0

	signal.Notify(signalChan, os.Interrupt, os.Kill, syscall.SIGTERM)

	select {
	case sig := <-signalChan:
		log.Info("Received signal %s. shutting down", sig)
	case code = <-exitChan:
		switch code {
		case 0:
			log.Info("Shutting down")
		default:
			log.Warn("Shutting down")
		}
	}

	log.Close()
	os.Exit(code)
}

func main() {
	buildstampInt64, _ := strconv.ParseInt(buildstamp, 10, 64)

	setting.BuildVersion = version
	setting.BuildCommit = commit
	setting.BuildStamp = buildstampInt64

	go func() {
		c := make(chan os.Signal, 1)
		signal.Notify(c, os.Interrupt)
		<-c
		os.Exit(0)
	}()

	flag.Parse()

	writePIDFile()
	initRuntime()

	search.Init()
	social.NewOAuthService()
	eventpublisher.Init()
	plugins.Init()
	metricpublisher.Init()
	elasticstore.Init()
	api.InitCollectorController()
	alerting.Init()

	if err := notifications.Init(); err != nil {
		log.Fatal(3, "Notification service failed to initialize", err)
	}

	if setting.ReportingEnabled {
		go metrics.StartUsageReportLoop()
	}

	cmd.StartServer()

	log.Close()
}

func initLogging(args *CommandLineArgs) {
	//close any existing log handlers.
	log.Close()
	// Get and check log mode.
	LogModes = strings.Split(Cfg.Section("log").Key("mode").MustString("console"), ",")
	LogsPath = makeAbsolute(Cfg.Section("paths").Key("logs").String(), HomePath)

	LogConfigs = make([]util.DynMap, len(LogModes))
	for i, mode := range LogModes {
		mode = strings.TrimSpace(mode)
		sec, err := Cfg.GetSection("log." + mode)
		if err != nil {
			log.Fatal(4, "Unknown log mode: %s", mode)
		}

		// Log level.
		levelName := Cfg.Section("log."+mode).Key("level").In("Trace",
			[]string{"Trace", "Debug", "Info", "Warn", "Error", "Critical"})
		level, ok := logLevels[levelName]
		if !ok {
			log.Fatal(4, "Unknown log level: %s", levelName)
		}

		// Generate log configuration.
		switch mode {
		case "console":
			formatting := sec.Key("formatting").MustBool(true)
			LogConfigs[i] = util.DynMap{
				"level":      level,
				"formatting": formatting,
			}
		case "file":
			logPath := sec.Key("file_name").MustString(filepath.Join(LogsPath, "grafana.log"))
			os.MkdirAll(filepath.Dir(logPath), os.ModePerm)
			LogConfigs[i] = util.DynMap{
				"level":    level,
				"filename": logPath,
				"rotate":   sec.Key("log_rotate").MustBool(true),
				"maxlines": sec.Key("max_lines").MustInt(1000000),
				"maxsize":  1 << uint(sec.Key("max_size_shift").MustInt(28)),
				"daily":    sec.Key("daily_rotate").MustBool(true),
				"maxdays":  sec.Key("max_days").MustInt(7),
			}
		case "conn":
			LogConfigs[i] = util.DynMap{
				"level":          level,
				"reconnectOnMsg": sec.Key("reconnect_on_msg").MustBool(),
				"reconnect":      sec.Key("reconnect").MustBool(),
				"net":            sec.Key("protocol").In("tcp", []string{"tcp", "unix", "udp"}),
				"addr":           sec.Key("addr").MustString(":7020"),
			}
		case "smtp":
			LogConfigs[i] = util.DynMap{
				"level":     level,
				"user":      sec.Key("user").MustString("[email protected]"),
				"passwd":    sec.Key("passwd").MustString("******"),
				"host":      sec.Key("host").MustString("127.0.0.1:25"),
				"receivers": sec.Key("receivers").MustString("[]"),
				"subject":   sec.Key("subject").MustString("Diagnostic message from serve"),
			}
		case "database":
			LogConfigs[i] = util.DynMap{
				"level":  level,
				"driver": sec.Key("driver").String(),
				"conn":   sec.Key("conn").String(),
			}
		case "syslog":
			LogConfigs[i] = util.DynMap{
				"level":    level,
				"network":  sec.Key("network").MustString(""),
				"address":  sec.Key("address").MustString(""),
				"facility": sec.Key("facility").MustString("local7"),
				"tag":      sec.Key("tag").MustString(""),
			}
		}

		cfgJsonBytes, _ := json.Marshal(LogConfigs[i])
		log.NewLogger(Cfg.Section("log").Key("buffer_len").MustInt64(10000), mode, string(cfgJsonBytes))
	}
}

func main() {
	buildstampInt64, _ := strconv.ParseInt(buildstamp, 10, 64)

	setting.BuildVersion = version
	setting.BuildCommit = commit
	setting.BuildStamp = buildstampInt64

	go func() {
		c := make(chan os.Signal, 1)
		signal.Notify(c, os.Interrupt)
		<-c
		os.Exit(0)
	}()

	flag.Parse()

	writePIDFile()
	initRuntime()

	if setting.ProfileHeapMB > 0 {
		errors := make(chan error)
		go func() {
			for e := range errors {
				log.Error(0, e.Error())
			}
		}()
		heap, _ := heap.New(setting.ProfileHeapDir, setting.ProfileHeapMB*1000000, setting.ProfileHeapWait, time.Duration(1)*time.Second, errors)
		go heap.Run()
	}

	search.Init()
	login.Init()
	social.NewOAuthService()
	eventpublisher.Init()
	plugins.Init()
	elasticstore.Init()
	models.InitQuotaDefaults()

	metricsBackend, err := helper.New(setting.StatsdEnabled, setting.StatsdAddr, setting.StatsdType, "grafana.")
	if err != nil {
		log.Error(3, "Statsd client:", err)
	}
	metricpublisher.Init(metricsBackend)
	api.InitCollectorController(metricsBackend)
	if setting.AlertingEnabled {
		alerting.Init(metricsBackend)
		alerting.Construct()
	}

	if err := notifications.Init(); err != nil {
		log.Fatal(3, "Notification service failed to initialize", err)
	}

	if setting.ReportingEnabled {
		go metrics.StartUsageReportLoop()
	}

	cmd.StartServer()

	log.Close()
}

//.........这里部分代码省略.........
	if err != nil {
		log.Fatal(0, "failed to parse nsq consumer options. %s", err)
	}
	cfg.MaxInFlight = *maxInFlight

	consumer, err := insq.NewConsumer(*topic, *channel, cfg, "%s", stats)
	if err != nil {
		log.Fatal(0, "Failed to create NSQ consumer. %s", err)
	}

	initMetrics(stats)

	err = InitCassandra()

	if err != nil {
		log.Fatal(4, "failed to initialize cassandra. %s", err)
	}

	set := strings.Split(*aggSettings, ",")
	finalSettings := make([]aggSetting, 0)
	for _, v := range set {
		if v == "" {
			continue
		}
		fields := strings.Split(v, ":")
		if len(fields) != 3 {
			log.Fatal(0, "bad agg settings")
		}
		aggSpan, err := strconv.Atoi(fields[0])
		if err != nil {
			log.Fatal(0, "bad agg settings", err)
		}
		aggChunkSpan, err := strconv.Atoi(fields[1])
		if err != nil {
			log.Fatal(0, "bad agg settings", err)
		}
		aggNumChunks, err := strconv.Atoi(fields[2])
		if err != nil {
			log.Fatal(0, "bad agg settings", err)
		}
		finalSettings = append(finalSettings, aggSetting{uint32(aggSpan), uint32(aggChunkSpan), uint32(aggNumChunks)})
	}

	metrics = NewAggMetrics(uint32(*chunkSpan), uint32(*numChunks), uint32(*chunkMaxStale), uint32(*metricMaxStale), finalSettings)
	handler := NewHandler(metrics)
	consumer.AddConcurrentHandlers(handler, *concurrency)

	nsqdAdds := strings.Split(*nsqdTCPAddrs, ",")
	if len(nsqdAdds) == 1 && nsqdAdds[0] == "" {
		nsqdAdds = []string{}
	}
	err = consumer.ConnectToNSQDs(nsqdAdds)
	if err != nil {
		log.Fatal(4, "failed to connect to NSQDs. %s", err)
	}
	log.Info("connected to nsqd")

	lookupdAdds := strings.Split(*lookupdHTTPAddrs, ",")
	if len(lookupdAdds) == 1 && lookupdAdds[0] == "" {
		lookupdAdds = []string{}
	}
	err = consumer.ConnectToNSQLookupds(lookupdAdds)
	if err != nil {
		log.Fatal(4, "failed to connect to NSQLookupds. %s", err)
	}

	go func() {
		m := &runtime.MemStats{}
		for range time.Tick(time.Duration(1) * time.Second) {
			runtime.ReadMemStats(m)
			alloc.Value(int64(m.Alloc))
			totalAlloc.Value(int64(m.TotalAlloc))
			sysBytes.Value(int64(m.Sys))
		}
	}()

	go func() {
		http.HandleFunc("/get", Get)
		log.Info("starting listener for metrics and http/debug on %s", *listenAddr)
		log.Info("%s", http.ListenAndServe(*listenAddr, nil))
	}()

	for {
		select {
		case <-consumer.StopChan:
			err := metrics.Persist()
			if err != nil {
				log.Error(3, "failed to persist aggmetrics. %s", err)
			}
			log.Info("closing cassandra session.")
			cSession.Close()
			log.Info("terminating.")
			log.Close()
			return
		case <-sigChan:
			log.Info("Shutting down")
			consumer.Stop()
		}
	}
}