golang实现权重轮询调度算法

package main    import (
    "fmt"
    "time"
    )    var slaveDns = map[int]map[string]interface{}{
    0: {"connectstring": "root@tcp(172.16.0.164:3306)/shiqu_tools?charset=utf8", "weight": 2},
    1: {"connectstring": "root@tcp(172.16.0.165:3306)/shiqu_tools?charset=utf8", "weight": 4},
    2: {"connectstring": "root@tcp(172.16.0.166:3306)/shiqu_tools?charset=utf8", "weight": 8},
    }    var i int = -1 //表示上一次选择的服务器
    var cw int = 0 //表示当前调度的权值
    var gcd int = 2 //当前所有权重的最大公约数 比如 2，4，8 的最大公约数为：2    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)
    }
    }

来源： http://studygolang.com/articles/8924