func mainBody(zkAddr string, productName string, serviceName string, frontendAddr string, backendAddr string) {
// 1. 创建到zk的连接
var topo *zk.Topology
topo = zk.NewTopology(productName, zkAddr)
// 2. 启动服务
frontend, _ := zmq.NewSocket(zmq.ROUTER)
backend, _ := zmq.NewSocket(zmq.ROUTER)
defer frontend.Close()
defer backend.Close()
// ROUTER/ROUTER绑定到指定的端口
// 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))
// 后端的workers queue
workersQueue := queue.NewPPQueue()
// 心跳间隔1s
heartbeat_at := time.Tick(HEARTBEAT_INTERVAL)
poller1 := zmq.NewPoller()
poller1.Add(backend, zmq.POLLIN)
poller2 := zmq.NewPoller()
// 前提:
// 1. 当zeromq通知消息可读时，那么整个Message(所有的msg parts)都可读
// 2. 往zeromq写数据时，是异步的，因此也不存在block(除非数据量巨大)
//
poller2.Add(backend, zmq.POLLIN)
poller2.Add(frontend, zmq.POLLIN)
// 3. 注册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 {
// 只是为了监控状态
_, 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过期了，则需要删除之前的数据，因为这个数据的Owner不是当前的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 还是留给运维吧
//
// 自动退出条件:
//
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
}
hasValidMsg := false
for _, socket := range sockets {
switch socket.Socket {
case backend:
// 格式:
// 后端:
// <"", proxy_id, "", client_id, "", rpc_data>
// Backend Socket读取到的:
// <wokerid, "", proxy_id, "", client_id, "", rpc_data>
//
msgs, err := backend.RecvMessage(0)
if err != nil {
log.Errorf("Error When RecvMessage from background: %v\n", err)
continue
}
if config.VERBOSE {
// log.Println("Message from backend: ", msgs)
}
// 消息类型:
// msgs: <worker_id, "", proxy_id, "", client_id, "", rpc_data>
// <worker_id, "", rpc_control_data>
worker_id, msgs := utils.Unwrap(msgs)
// rpc_control_data 控制信息
// msgs: <rpc_control_data>
if len(msgs) == 1 {
// PPP_READY
// PPP_HEARTBEAT
controlMsg := msgs[0]
// 碰到无效的信息，则直接跳过去
if len(controlMsg) == 0 {
continue
}
if config.VERBOSE {
// log.Println("Got Message From Backend...")
}
if controlMsg[0] == PPP_READY || controlMsg[0] == PPP_HEARTBEAT {
// 后端服务剩余的并发能力
var concurrency int
if len(controlMsg) >= 3 {
concurrency = int(controlMsg[2])
} else {
concurrency = 1
}
if config.VERBOSE {
// utils.PrintZeromqMsgs(msgs, "control msg")
}
force_update := controlMsg[0] == PPP_READY
workersQueue.UpdateWorkerStatus(worker_id, concurrency, force_update)
} else if controlMsg[0] == PPP_STOP {
// 停止指定的后端服务
workersQueue.UpdateWorkerStatus(worker_id, -1, true)
} else {
log.Errorf("Unexpected Control Message: %d", controlMsg[0])
}
} else {
hasValidMsg = true
// 将信息发送到前段服务, 如果前端服务挂了，则消息就丢失
// log.Println("Send Message to frontend")
workersQueue.UpdateWorkerStatus(worker_id, 0, false)
// msgs: <proxy_id, "", client_id, "", rpc_data>
frontend.SendMessage(msgs)
}
case frontend:
hasValidMsg = true
log.Println("----->Message from front: ")
msgs, err := frontend.RecvMessage(0)
if err != nil {
log.Errorf("Error when reading from frontend: %v\n", err)
continue
}
// msgs:
// <proxy_id, "", client_id, "", rpc_data>
if config.VERBOSE {
utils.PrintZeromqMsgs(msgs, "frontend")
}
msgs = utils.TrimLeftEmptyMsg(msgs)
// 将msgs交给后端服务器
worker := workersQueue.NextWorker()
if worker != nil {
if config.VERBOSE {
log.Println("Send Msg to Backend worker: ", worker.Identity)
}
backend.SendMessage(worker.Identity, "", msgs)
} else {
// 怎么返回错误消息呢?
if config.VERBOSE {
log.Println("No backend worker found")
}
errMsg := proxy.GetWorkerNotFoundData("account", 0)
// <proxy_id, "", client_id, "", rpc_data>
frontend.SendMessage(msgs[0:(len(msgs)-1)], errMsg)
}
}
}
// 如果安排的suiside, 则需要处理 suiside的时间
isAliveLock.RLock()
isAlive1 := isAlive
isAliveLock.RUnlock()
if !isAlive1 {
if hasValidMsg {
suideTime = time.Now().Add(time.Second * 3)
} else {
if time.Now().After(suideTime) {
log.Println(utils.Green("Load Balance Suiside Gracefully"))
break
}
}
}
// 心跳同步
select {
case <-heartbeat_at:
now := time.Now()
// 给workerQueue中的所有的worker发送心跳消息
for _, worker := range workersQueue.WorkerQueue {
if worker.Expire.After(now) {
// log.Println("Sending Hb to Worker: ", worker.Identity)
backend.SendMessage(worker.Identity, "", PPP_HEARTBEAT_STR)
}
}
workersQueue.PurgeExpired()
case sig := <-ch:
isAliveLock.Lock()
isAlive1 := isAlive
isAlive = false
isAliveLock.Unlock()
if isAlive1 {
// 准备退出(但是需要处理完毕手上的活)
// 需要退出:
topo.DeleteServiceEndPoint(serviceName, lbServiceName)
if sig == syscall.SIGKILL {
log.Println(utils.Red("Got Kill Signal, Return Directly"))
break
} else {
suideTime = time.Now().Add(time.Second * 3)
log.Println(utils.Red("Schedule to suicide at: "), suideTime.Format("@2006-01-02 15:04:05"))
}
}
default:
}
}
}
//
// 两参数是必须的: ProductName, zkAddress, frontAddr可以用来测试
//
func mainBody(productName string, frontAddr string, zkAdresses string) {
// 1. 创建到zk的连接
var topo *zk.Topology
topo = zk.NewTopology(productName, zkAdresses)
// 3. 读取后端服务的配置
poller := zmq.NewPoller()
backServices := proxy.NewBackServices(poller, productName, topo)
// 4. 创建前端服务
frontend, _ := zmq.NewSocket(zmq.ROUTER)
defer frontend.Close()
// ROUTER/ROUTER绑定到指定的端口
log.Println("---->Bind: ", magenta(frontAddr))
frontend.Bind(frontAddr) // For clients
// 开始监听前端服务
poller.Add(frontend, zmq.POLLIN)
for {
var sockets []zmq.Polled
var err error
sockets, err = poller.Poll(HEARTBEAT_INTERVAL)
if err != nil {
log.Println("Encounter Errors, Services Stoped: ", err)
continue
}
for _, socket := range sockets {
switch socket.Socket {
case frontend:
if config.VERBOSE {
log.Println("----->Message from front: ")
}
msgs, err := frontend.RecvMessage(0)
if err != nil {
continue // Interrupted
}
var service string
var client_id string
utils.PrintZeromqMsgs(msgs, "ProxyFrontEnd")
// msg格式: <client_id, '', service, '', other_msgs>
client_id, msgs = utils.Unwrap(msgs)
service, msgs = utils.Unwrap(msgs)
// log.Println("Client_id: ", client_id, ", Service: ", service)
backService := backServices.GetBackService(service)
if backService == nil {
log.Println("BackService Not Found...")
// 最后一个msg为Thrift编码后的消息
thriftMsg := msgs[len(msgs)-1]
// XXX: seqId如果不需要，也可以使用固定的数字
_, _, seqId, _ := proxy.ParseThriftMsgBegin([]byte(thriftMsg))
errMsg := proxy.GetServiceNotFoundData(service, seqId)
// <client_id, "", errMsg>
if len(msgs) > 1 {
frontend.SendMessage(client_id, "", msgs[0:len(msgs)-1], errMsg)
} else {
frontend.SendMessage(client_id, "", errMsg)
}
} else {
// <"", client_id, "", msgs>
if config.PROFILE {
lastMsg := msgs[len(msgs)-1]
msgs = msgs[0 : len(msgs)-1]
msgs = append(msgs, fmt.Sprintf("%.4f", float64(time.Now().UnixNano())*1e-9), "", lastMsg)
if config.VERBOSE {
log.Println(printList(msgs))
}
}
total, err, errMsg := backService.HandleRequest(client_id, msgs)
if errMsg != nil {
if config.VERBOSE {
log.Println("backService Error for service: ", service)
}
if len(msgs) > 1 {
frontend.SendMessage(client_id, "", msgs[0:len(msgs)-1], *errMsg)
} else {
frontend.SendMessage(client_id, "", *errMsg)
}
} else if err != nil {
log.Println(utils.Red("backService.HandleRequest Error: "), err, ", Total: ", total)
}
}
default:
// 除了来自前端的数据，其他的都来自后端
msgs, err := socket.Socket.RecvMessage(0)
if err != nil {
log.Println("Encounter Errors When receiving from background")
continue // Interrupted
}
if config.VERBOSE {
utils.PrintZeromqMsgs(msgs, "proxy")
}
msgs = utils.TrimLeftEmptyMsg(msgs)
// msgs格式: <client_id, "", rpc_data>
// <control_msg_rpc_data>
if len(msgs) == 1 {
// 告知后端的服务可能有问题
} else {
if config.PROFILE {
lastMsg := msgs[len(msgs)-1]
msgs = msgs[0 : len(msgs)-1]
msgs = append(msgs, fmt.Sprintf("%.4f", float64(time.Now().UnixNano())*1e-9), "", lastMsg)
}
if config.VERBOSE {
log.Println(printList(msgs))
}
frontend.SendMessage(msgs)
}
}
}
}
}