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tcp keepalive in go

Posted on Edited on In

http 1.1 默认开启了 tcp keepalive,复用 tcp 连接. go 中发起 http 请求,如何使用 keepalive 呢?

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package main
var (
	QHTTPTransport http.RoundTripper = &http.Transport{
		Proxy: http.ProxyFromEnvironment,
		DialContext: (&net.Dialer{
			Timeout:   30 * time.Second,
			KeepAlive: 30 * time.Second,
			DualStack: true,
		}).DialContext,
		MaxIdleConns:          100,
		MaxIdleConnsPerHost:   5,
		IdleConnTimeout:       90 * time.Second,
		TLSHandshakeTimeout:   10 * time.Second,
		ExpectContinueTimeout: 1 * time.Second,
	}

	QHTTPClient = &http.Client{
		Transport: QHTTPTransport,
	}
)

发起 http 请求时,使用 QHTTPClient.
go 服务端 http.ListenAndServe(":8080",nil) 默认开启了 keepalive.

使用 man 7 tcp查看 tcp_keepalive_time,默认保持时间是 7200秒,tcp_keepalive_intvl默认是 75秒
自定义:

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   srv := http.Server{
	Handler: mux,
}
srv.SetKeepAlivesEnabled(false)

或者自定义 listener

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type tcpKeepAliveListener struct {
	*net.TCPListener
}

func (ln tcpKeepAliveListener) Accept() (net.Conn, error) {
	tc, err := ln.AcceptTCP()
	if err != nil {
		return nil, err
	}
	tc.SetKeepAlive(true)
	tc.SetKeepAlivePeriod(time.Second*10) // 设置 keepalive period
	return tc, nil
}
func main(){
    err = srv.Serve(tcpKeepAliveListener{ln.(*net.TCPListener)})
}

gin 框架自定义 keepalive

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router := gin.Default()

   s := &http.Server{
       Addr:           ":8080",
       Handler:        router, // < here Gin is attached to the HTTP server
   }
   s.SetKeepAlivesEnabled(false)
   s.ListenAndServe()