package main

import (
    "io"
    "net/http"
)

func hello(w http.ResponseWriter, r *http.Request) {
    io.WriteString(w, "Hello world!\n")
}

func main() {
    http.HandleFunc("/", hello)
    http.ListenAndServe(":8000", nil)
}

我有几个令人难以置信的基本HTTP服务器，而且所有这些服务器都存在此问题。

$ ab -c 1000 -n 10000 http://127.0.0.1:8000/
This is ApacheBench, Version 2.3 <$Revision: 1604373 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient)
Completed 1000 requests
Completed 2000 requests
Completed 3000 requests
Completed 4000 requests
Completed 5000 requests
apr_socket_recv: Connection refused (61)
Total of 5112 requests completed

并发值较小时，事情仍然会失败。对我来说，这个问题似乎通常出现在5k-6k大关附近：

$ ab -c 10 -n 10000 http://127.0.0.1:8000/
This is ApacheBench, Version 2.3 <$Revision: 1604373 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient)
Completed 1000 requests
Completed 2000 requests
Completed 3000 requests
Completed 4000 requests
Completed 5000 requests
Completed 6000 requests
apr_socket_recv: Operation timed out (60)
Total of 6277 requests completed

实际上，您可以完全放弃并发性，问题仍然存在（有时）：

$ ab -c 1 -n 10000 http://127.0.0.1:8000/
This is ApacheBench, Version 2.3 <$Revision: 1604373 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking 127.0.0.1 (be patient)
Completed 1000 requests
Completed 2000 requests
Completed 3000 requests
Completed 4000 requests
Completed 5000 requests
Completed 6000 requests
apr_socket_recv: Operation timed out (60)
Total of 6278 requests completed

我忍不住想知道是否在某处达到某种操作系统限制？我怎么知道 我该如何缓解？