golang框架性能优化中的负载均衡策略？

import (
    "context"
    "log"
    "net/http"
    "sync"
)

var servers = []string{"server1", "server2", "server3"}
var i int  // 轮询计数器
var mux sync.Mutex  // 互斥锁

func main() {
    http.HandleFunc("/", handler)
    log.Fatal(http.ListenAndServe(":8080", nil))
}

func handler(w http.ResponseWriter, r *http.Request) {
    mux.Lock()
    server := servers[i%len(servers)]
    i++
    mux.Unlock()
    // 省略与后端服务器通信的代码...
}

import (
    "context"
    "log"
    "net/http"
    "sync"
)

type serverInfo struct {
    name    string
    weight  float64
    current float64  // 当前权重
}

var servers = []serverInfo{
    {"server1", 1.0, 0},
    {"server2", 1.5, 0},
    {"server3", 2.0, 0},
}
var totalWeight float64 // 所有服务器权重之和
var mux sync.Mutex  // 互斥锁

func main() {
    // 计算总权重
    for _, server := range servers {
        totalWeight += server.weight
    }
    http.HandleFunc("/", handler)
    log.Fatal(http.ListenAndServe(":8080", nil))
}

func handler(w http.ResponseWriter, r *http.Request) {
    // 省略选择服务器的代码
    //...
    // 省略与后端服务器通信的代码...
}

import (
    "context"
    "log"
    "net/http"
    "sort"
)

type serverInfo struct {
    name string
    hash uint64  // 哈希值
}

var servers = []serverInfo{...}  // 省略服务器列表初始化代码

func main() {
    sort.Slice(servers, func(i, j int) bool {
        return servers[i].hash < servers[j].hash
    })
    http.HandleFunc("/", handler)
    log.Fatal(http.ListenAndServe(":8080", nil))
}

func handler(w http.ResponseWriter, r *http.Request) {
    hash := getHashFromRequest(r)
    index := sort.Search(len(servers), func(i int) bool {
        return hash < servers[i].hash
    })
    // 省略与服务器通信的代码...
}