參考<<權重輪詢排程演算法(Weighted Round-Robin Scheduling)>>這篇文章寫了一個golang版本的權重輪詢排程演算法，請大家指教，不多說了直接上程式碼：

package main

import (
	"fmt"
	"time"
)

var slaveDns = map[int]map[string]interface{}{
	0: {"connectstring": "[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8", "weight": 8},
	1: {"connectstring": "
 
[email protected](172.16.0.165:3306)/shiqu_tools?charset=utf8", "weight": 4},
	2: {"connectstring": "[email protected](172.16.0.166:3306)/shiqu_tools?charset=utf8", "weight": 2},
}

var i int = -1  //表示上一次選擇的伺服器
var cw int = 0  //表示當前排程的權值
var gcd int = 2 //當前所有權重的最大公約數 比如 2，4，8 的最大公約數為：2
/*
演算法思路：
cw為當前的權重，遍歷每個伺服器，如果伺服器的權值大於cw，則該伺服器執行一次，一輪輪詢之後，cw-gcd；
之後重複上訴步驟
*/
func getDns() string {
	for {
		i = (i + 1) % len(slaveDns)
		if i == 0 {
			cw = cw - gcd
			if cw <= 0 {
				cw = getMaxWeight()
				if cw == 0 {
					return ""
				}
			}
		}

		if weight, _ := slaveDns[i]["weight"].(int); weight >= cw {
			return slaveDns[i]["connectstring"].(string)
		}
	}
}

func getMaxWeight() int {
	max := 0
	for _, v := range slaveDns {
		if weight, _ := v["weight"].(int); weight >= max {
			max = weight
		}
	}

	return max
}

func main() {

	note := map[string]int{}

	s_time := time.Now().Unix()

	for i := 0; i < 100; i++ {
		s := getDns()
		fmt.Println(s)
		if note[s] != 0 {
			note[s]++
		} else {
			note[s] = 1
		}
	}

	e_time := time.Now().Unix()

	fmt.Println("total time: ", e_time-s_time)

	fmt.Println("--------------------------------------------------")

	for k, v := range note {
		fmt.Println(k, " ", v)
	}
}
 

執行結果：

C:/go/bin/go.exe build [D:/PROGRAM/Golang/src/study/roundRobin]
成功: 程序退出程式碼 0.
D:/PROGRAM/Golang/src/study/roundRobin/roundRobin.exe  [D:/PROGRAM/Golang/src/study/roundRobin]
[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8
[email protected]
 
(172.16.0.164:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.165:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.165:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.166:3306)/shiqu_tools?charset=utf8
。。。（中間部分省略）
[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.165:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.165:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.166:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8
[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8
total time:  0
--------------------------------------------------
[email protected](172.16.0.164:3306)/shiqu_tools?charset=utf8   58
[email protected](172.16.0.165:3306)/shiqu_tools?charset=utf8   28
[email protected](172.16.0.166:3306)/shiqu_tools?charset=utf8   14
成功: 程序退出程式碼 0.