balancer.go

package main

import (
	"math/rand"
	"net"
	"time"

	"stathat.com/c/consistent"
)

// 代理服务的结构
type BackendSvr struct {
	identify  string
	isLive    bool // 服务是否存活
	failTimes int
}

var (
	Consisthash *consistent.Consistent
	BackendSvrs map[string]*BackendSvr
)

// 初始化代理服务，加入一致性哈希列表，开始检测服务
func initBackendSvrs(serverList []string) {
	Consisthash = consistent.New()
	BackendSvrs = make(map[string]*BackendSvr)
	for _, server := range serverList {
		Consisthash.Add(server)
		BackendSvrs[server] = &BackendSvr{
			identify:  server,
			isLive:    true,
			failTimes: 0,
		}
	}
	go checkBackendSvrs()
}

// 根据客户端链接，从哈希集群中选择一台机器
func getBackendSvr(conn net.Conn) (*BackendSvr, bool) {
	remoteAddr := conn.RemoteAddr().String()
	identify, _ := Consisthash.Get(remoteAddr)
	BackendSvr, ok := BackendSvrs[identify]
	return BackendSvr, ok
}

// 代理服务检测存活
func checkBackendSvrs() {
	rand.Seed(time.Now().UnixNano())
	// 设置定时（10s对服务进行检测）执行管道
	ticker := time.Tick(time.Duration(10) * time.Second)
	for _ = range ticker {
		for _, server := range BackendSvrs {
			if server.failTimes >= Config.FailOver && server.isLive == true {
				server.isLive = false
				Consisthash.Remove(server.identify)
			}
		}
	}
}

// 设置定时器
func timer(input chan interface{}) {
	timerOne := time.NewTimer(time.Second * 5)
	timerTwo := time.NewTimer(time.Second * 10)
	for {
		select {
		case msg := <-input:
			println(msg)

		case <-timerOne.C:
			println("5s timer")
			timerOne.Reset(time.Second * 5)

		case <-timerTwo.C:
			println("10s timer")
			timerTwo.Reset(time.Second * 10)
		}
	}
}