在Ubuntu AWS EC2实例上优化Golang net/http服务器性能

要优化Go net/http服务器在AWS EC2实例上的性能并充分利用CPU资源，需要从多个层面进行调优。以下是具体的优化方案：

1. 优化Go HTTP服务器配置

package main

import (
    "fmt"
    "log"
    "net/http"
    "runtime"
    "strings"
    "time"
)

var (
    chars_10 string
)

func main() {
    // 设置最大CPU核心数
    runtime.GOMAXPROCS(runtime.NumCPU())
    
    chars_10 = strings.Repeat("a", 10)
    
    // 创建自定义HTTP服务器配置
    server := &http.Server{
        Addr: ":8888",
        Handler: http.HandlerFunc(handler_10_chars),
        ReadTimeout:    10 * time.Second,
        WriteTimeout:   10 * time.Second,
        IdleTimeout:    30 * time.Second,
        MaxHeaderBytes: 1 << 20, // 1MB
    }
    
    log.Fatal(server.ListenAndServe())
}

func handler_10_chars(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, chars_10)
}

2. 使用更高效的HTTP路由器

package main

import (
    "fmt"
    "log"
    "net/http"
    "runtime"
    "strings"
    "time"
    
    "github.com/gorilla/mux"
)

var (
    chars_10 string
)

func main() {
    runtime.GOMAXPROCS(runtime.NumCPU())
    
    chars_10 = strings.Repeat("a", 10)
    
    router := mux.NewRouter()
    router.HandleFunc("/experiment-1/10-characters", handler_10_chars)
    
    server := &http.Server{
        Addr:         ":8888",
        Handler:      router,
        ReadTimeout:  5 * time.Second,
        WriteTimeout: 10 * time.Second,
        IdleTimeout:  120 * time.Second,
    }
    
    log.Fatal(server.ListenAndServe())
}

func handler_10_chars(w http.ResponseWriter, r *http.Request) {
    w.Header().Set("Content-Type", "text/plain")
    fmt.Fprintf(w, chars_10)
}

3. 优化系统级别的配置

在Ubuntu上创建systemd服务文件 /etc/systemd/system/go-server.service：

[Unit]
Description=Go HTTP Server
After=network.target

[Service]
Type=simple
User=ubuntu
Group=ubuntu
WorkingDirectory=/path/to/your/app
ExecStart=/path/to/your/server
Restart=always
LimitNOFILE=1000000
LimitNPROC=1000000

[Install]
WantedBy=multi-user.target

4. 使用连接池优化客户端请求

// 在K6测试中优化连接重用
import http from "k6/http";
import { check } from "k6";

export let options = {
   vus: 2048,
   duration: "60s",
};

// 创建HTTP客户端实例以重用连接
const client = new http.Client({
    timeout: '30s',
});

let url = "http://your-aws-url:8888/experiment-1/10-characters";

export default function() {
    let res = client.get(url);
    check(res, {
        "status was 200": (r) => r.status == 200,
    });
};

5. 启用HTTP/2和优化TLS配置（如果使用HTTPS）

package main

import (
    "fmt"
    "log"
    "net/http"
    "runtime"
    "strings"
    "time"
)

func main() {
    runtime.GOMAXPROCS(runtime.NumCPU())
    
    chars_10 := strings.Repeat("a", 10)
    
    server := &http.Server{
        Addr: ":8888",
        Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
            fmt.Fprintf(w, chars_10)
        }),
        ReadTimeout:       5 * time.Second,
        WriteTimeout:      10 * time.Second,
        IdleTimeout:       120 * time.Second,
        ReadHeaderTimeout: 2 * time.Second,
    }
    
    // 启用HTTP/2
    log.Fatal(server.ListenAndServe())
}

6. 监控和性能分析

添加性能监控端点：

package main

import (
    "fmt"
    "log"
    "net/http"
    _ "net/http/pprof"
    "runtime"
    "strings"
    "time"
)

func main() {
    runtime.GOMAXPROCS(runtime.NumCPU())
    
    chars_10 := strings.Repeat("a", 10)
    
    // 启用pprof性能分析
    go func() {
        log.Println(http.ListenAndServe("localhost:6060", nil))
    }()
    
    http.HandleFunc("/experiment-1/10-characters", func(w http.ResponseWriter, r *http.Request) {
        fmt.Fprintf(w, chars_10)
    })
    
    server := &http.Server{
        Addr: ":8888",
        ReadTimeout:  5 * time.Second,
        WriteTimeout: 10 * time.Second,
        IdleTimeout:  120 * time.Second,
    }
    
    log.Fatal(server.ListenAndServe())
}

潜在瓶颈分析：

1. 网络带宽限制：t2.micro实例的网络性能有限
2. 实例类型限制：t2.micro是突发性能实例，持续高负载时CPU积分会耗尽
3. 系统调用开销：大量的小HTTP请求会产生显著的系统调用开销
4. 内存分配：频繁的字符串操作和HTTP响应构建可能产生GC压力

要验证这些优化效果，可以使用以下命令监控服务器性能：

# 监控CPU使用率
htop

# 监控网络连接
netstat -an | grep :8888 | wc -l

# 监控文件描述符使用
lsof -p $(pgrep server) | wc -l

这些优化应该能够帮助Go服务器更有效地利用CPU资源，但需要注意t2.micro实例本身的性能限制可能仍然是主要瓶颈。