// 从Client读取数据
func (s *Session) loopReader(tasks chan<- *Request, d Dispatcher) error {
if d == nil {
return errors.New("nil dispatcher")
}
for !s.quit {
// client <--> rpc
// 从client读取frames
request, err := s.ReadFrame()
if err != nil {
err1, ok := err.(thrift.TTransportException)
if !ok || err1.TypeId() != thrift.END_OF_FILE {
// 遇到EOF等错误，就直接结束loopReader
// 结束之前需要和后端的back_conn之间处理好关系?
log.ErrorErrorf(err, Red("ReadFrame Error: %v"), err)
}
return err
}
r, err := s.handleRequest(request, d)
if err != nil {
return err
} else {
if s.verbose {
log.Info("Succeed Get Result")
}
// 将请求交给: tasks, 同一个Session中的请求是
tasks <- r
}
}
return nil
}
func (s *Session) Serve(d Dispatcher, maxPipeline int) {
var errlist errors.ErrorList
defer func() {
log.Infof(Red("==> Session Over: %s, Print Error List: %d Errors"),
s.RemoteAddress, errlist.Len())
// 只打印第一个Error
if err := errlist.First(); err != nil {
log.Infof("==> Session [%p] closed, Error = %v", s, err)
} else {
log.Infof("==> Session [%p] closed, Quit", s)
}
}()
// 来自connection的各种请求
tasks := make(chan *Request, maxPipeline)
go func() {
defer func() {
// 出现错误了，直接关闭Session
s.Close()
// 扔掉所有的Tasks
log.Warnf(Red("Session Closed, Abandon %d Tasks"), len(tasks))
for task := range tasks {
task.Recycle()
}
}()
if err := s.loopWriter(tasks); err != nil {
errlist.PushBack(err)
}
}()
defer close(tasks)
// 从Client读取用户的请求，然后再交给Dispatcher来处理
if err := s.loopReader(tasks, d); err != nil {
errlist.PushBack(err)
}
log.Info(Cyan("LoopReader Over, Session#Serve Over"))
}
func (p *ThriftLoadBalanceServer) Run() {
// // 1. 创建到zk的连接
// 127.0.0.1:5555 --> 127_0_0_1:5555
exitSignal := make(chan os.Signal, 1)
signal.Notify(exitSignal, syscall.SIGTERM, syscall.SIGINT, syscall.SIGKILL)
// syscall.SIGKILL
// kill -9 pid
// kill -s SIGKILL pid 还是留给运维吧
//
// 注册服务
evtExit := make(chan interface{})
serviceEndpoint := RegisterService(p.serviceName, p.frontendAddr, p.lbServiceName,
p.topo, evtExit, p.config.WorkDir, p.config.CodeUrlVersion)
// var suideTime time.Time
// isAlive := true
// 3. 读取后端服务的配置
var transport thrift.TServerTransport
var err error
isUnixDomain := false
// 127.0.0.1:9999(以:区分不同的类型)
if !strings.Contains(p.frontendAddr, ":") {
if FileExist(p.frontendAddr) {
os.Remove(p.frontendAddr)
}
transport, err = NewTServerUnixDomain(p.frontendAddr)
isUnixDomain = true
} else {
transport, err = thrift.NewTServerSocket(p.frontendAddr)
}
if err != nil {
log.ErrorErrorf(err, "Server Socket Create Failed: %v", err)
panic(fmt.Sprintf("Invalid FrontendAddress: %s", p.frontendAddr))
}
err = transport.Listen()
if err != nil {
log.ErrorErrorf(err, "Server Socket Create Failed: %v", err)
panic(fmt.Sprintf("Binding Error FrontendAddress: %s", p.frontendAddr))
}
ch := make(chan thrift.TTransport, 4096)
defer close(ch)
// 强制退出? TODO: Graceful退出
go func() {
<-exitSignal
// 通知RegisterService终止循环
evtExit <- true
log.Info(Green("Receive Exit Signals...."))
serviceEndpoint.DeleteServiceEndpoint(p.topo)
start := time.Now().Unix()
for true {
// 如果5s内没有接受到新的请求了，则退出
now := time.Now().Unix()
if now-p.lastRequestTime.Get() > 5 {
log.Printf(Red("[%s]Graceful Exit..."), p.serviceName)
break
} else {
log.Printf(Cyan("[%s]Sleeping %d seconds before Exit...\n"),
p.serviceName, now-start)
time.Sleep(time.Second)
}
}
transport.Interrupt()
transport.Close()
}()
go func() {
var address string
for c := range ch {
// 为每个Connection建立一个Session
socket, ok := c.(SocketAddr)
if ok {
if isUnixDomain {
address = p.frontendAddr
} else {
address = socket.Addr().String()
}
} else {
address = "unknow"
}
x := NewNonBlockSession(c, address, p.verbose, &p.lastRequestTime)
// Session独立处理自己的请求
go x.Serve(p.backendService, 1000)
}
}()
// Accept什么时候出错，出错之后如何处理呢?
for {
c, err := transport.Accept()
if err != nil {
close(ch)
break
} else {
ch <- c
}
}
}
func (s *BackServiceLB) run() {
go func() {
// 定时汇报当前的状态
for true {
log.Printf(Green("[Report]: %s --> %d workers, coroutine: %d"),
s.serviceName, s.Active(), runtime.NumGoroutine())
time.Sleep(time.Second * 10)
}
}()
var transport thrift.TServerTransport
var err error
// 3. 读取后端服务的配置
isUnixDomain := false
// 127.0.0.1:9999(以:区分不同的类型)
if !strings.Contains(s.backendAddr, ":") {
if FileExist(s.backendAddr) {
os.Remove(s.backendAddr)
}
transport, err = NewTServerUnixDomain(s.backendAddr)
isUnixDomain = true
} else {
transport, err = thrift.NewTServerSocket(s.backendAddr)
}
if err != nil {
log.ErrorErrorf(err, "[%s]Server Socket Create Failed: %v", s.serviceName, err)
panic("BackendAddr Invalid")
}
err = transport.Listen()
if err != nil {
log.ErrorErrorf(err, "[%s]Server Socket Open Failed: %v", s.serviceName, err)
panic("Server Socket Open Failed")
}
// 和transport.open做的事情一样，如果Open没错，则Listen也不会有问题
log.Printf(Green("[%s]LB Backend Services listens at: %s"), s.serviceName, s.backendAddr)
s.ch = make(chan thrift.TTransport, 4096)
// 强制退出? TODO: Graceful退出
go func() {
<-s.exitEvt
log.Info(Red("Receive Exit Signals...."))
transport.Interrupt()
transport.Close()
}()
go func() {
var backendAddr string
for trans := range s.ch {
// 为每个Connection建立一个Session
socket, ok := trans.(SocketAddr)
if ok {
if isUnixDomain {
backendAddr = s.backendAddr
} else {
backendAddr = socket.Addr().String()
}
conn := NewBackendConnLB(trans, s.serviceName, backendAddr, s, s.verbose)
// 因为连接刚刚建立，可靠性还是挺高的，因此直接加入到列表中
s.activeConnsLock.Lock()
conn.Index = len(s.activeConns)
s.activeConns = append(s.activeConns, conn)
s.activeConnsLock.Unlock()
log.Printf(Green("%s --> %d workers"), s.serviceName, conn.Index)
} else {
panic("Invalid Socket Type")
}
}
}()
// Accept什么时候出错，出错之后如何处理呢?
go func() {
for {
c, err := transport.Accept()
if err != nil {
return
} else {
s.ch <- c
}
}
}()
}