Golang Topology.ProductServicePath方法代碼示例

// 創建一個BackService
func NewBackService(serviceName string, poller *zmq.Poller, topo *zk.Topology) *BackService {

	backSockets := NewBackSockets(poller)

	service := &BackService{
		ServiceName: serviceName,
		backend:     backSockets,
		poller:      poller,
		topo:        topo,
	}

	var evtbus chan interface{} = make(chan interface{}, 2)
	servicePath := topo.ProductServicePath(serviceName)
	endpoints, err := topo.WatchChildren(servicePath, evtbus)
	if err != nil {
		log.Println("Error: ", err)
		panic("Reading Service List Failed: ")
	}

	go func() {
		for true {
			// 如何監聽endpoints的變化呢?
			addrSet := make(map[string]bool)
			nowStr := time.Now().Format("@2006-01-02 15:04:05")
			for _, endpoint := range endpoints {
				// 這些endpoint變化該如何處理呢?
				log.Println(utils.Green("---->Find Endpoint: "), endpoint, "For Service: ", serviceName)
				endpointInfo, _ := topo.GetServiceEndPoint(serviceName, endpoint)

				addr, ok := endpointInfo["frontend"]
				if ok {
					addrStr := addr.(string)
					log.Println(utils.Green("---->Add endpoint to backend: "), addrStr, nowStr, "For Service: ", serviceName)
					addrSet[addrStr] = true
				}
			}

			service.backend.UpdateEndpointAddrs(addrSet)

			// 等待事件
			<-evtbus
			// 讀取數據，繼續監聽
			endpoints, err = topo.WatchChildren(servicePath, evtbus)
		}
	}()

	ticker := time.NewTicker(time.Millisecond * 1000)
	go func() {
		for _ = range ticker.C {
			service.backend.PurgeEndpoints()
		}
	}()

	return service

}

func mainBody(zkAddr string, productName string, serviceName string, frontendAddr string, backendAddr string) {
	// 1. 創建到zk的連接
	var topo *zk.Topology
	topo = zk.NewTopology(productName, zkAddr)

	// 2. 啟動服務
	frontend, _ := zmq.NewSocket(zmq.ROUTER)
	backend, _ := zmq.NewSocket(zmq.ROUTER)
	defer frontend.Close()
	defer backend.Close()

	// ROUTER/ROUTER綁定到指定的端口

	// tcp://127.0.0.1:5555 --> tcp://127_0_0_1:5555
	lbServiceName := GetServiceIdentity(frontendAddr)

	frontend.SetIdentity(lbServiceName)
	frontend.Bind(frontendAddr) //  For clients "tcp://*:5555"
	backend.Bind(backendAddr)   //  For workers "tcp://*:5556"

	log.Printf("FrontAddr: %s, BackendAddr: %s\n", magenta(frontendAddr), magenta(backendAddr))

	// 後端的workers queue
	workersQueue := queue.NewPPQueue()

	// 心跳間隔1s
	heartbeat_at := time.Tick(HEARTBEAT_INTERVAL)

	poller1 := zmq.NewPoller()
	poller1.Add(backend, zmq.POLLIN)

	poller2 := zmq.NewPoller()
	// 前提:
	//     1. 當zeromq通知消息可讀時，那麽整個Message(所有的msg parts)都可讀
	//	   2. 往zeromq寫數據時，是異步的，因此也不存在block(除非數據量巨大)
	//
	poller2.Add(backend, zmq.POLLIN)
	poller2.Add(frontend, zmq.POLLIN)

	// 3. 注冊zk
	var endpointInfo map[string]interface{} = make(map[string]interface{})
	endpointInfo["frontend"] = frontendAddr
	endpointInfo["backend"] = backendAddr

	topo.AddServiceEndPoint(serviceName, lbServiceName, endpointInfo)

	isAlive := true
	isAliveLock := &sync.RWMutex{}

	go func() {
		servicePath := topo.ProductServicePath(serviceName)
		evtbus := make(chan interface{})
		for true {
			// 隻是為了監控狀態
			_, err := topo.WatchNode(servicePath, evtbus)

			if err == nil {
				// 等待事件
				e := (<-evtbus).(topozk.Event)
				if e.State == topozk.StateExpired || e.Type == topozk.EventNotWatching {
					// Session過期了，則需要刪除之前的數據，因為這個數據的Owner不是當前的Session
					topo.DeleteServiceEndPoint(serviceName, lbServiceName)
					topo.AddServiceEndPoint(serviceName, lbServiceName, endpointInfo)
				}
			} else {
				time.Sleep(time.Second)
			}

			isAliveLock.RLock()
			isAlive1 := isAlive
			isAliveLock.RUnlock()
			if !isAlive1 {
				break
			}

		}
	}()

	ch := make(chan os.Signal, 1)

	signal.Notify(ch, syscall.SIGTERM, syscall.SIGINT, syscall.SIGKILL)
	// syscall.SIGKILL
	// kill -9 pid
	// kill -s SIGKILL pid 還是留給運維吧
	//

	// 自動退出條件:
	//

	var suideTime time.Time

	for {
		var sockets []zmq.Polled
		var err error

		sockets, err = poller2.Poll(HEARTBEAT_INTERVAL)
		if err != nil {
			//			break //  Interrupted
			log.Errorf("Error When Pollling: %v\n", err)
			continue
//.........這裏部分代碼省略.........