golang http连接复用方法
时间：2020-12-25 12:28:13|栏目：Golang|点击： 次
server端
golang httpserver 默认开启keepalive连接复用选项
handler函数需要完整读body数据，构造返回消息，否则当数据不能一次发送完成时，连接复用就会失效。
示例如下
package main
import (
"fmt"
"io/ioutil"
"log"
"net/http"
"os"
"strconv"
"strings"
"time"
)
func connHandler(w http.ResponseWriter, r *http.Request) {
// parse
r.ParseForm()
response_time := r.Header.Get("sleep-time")
// <= NOTE
if _, err := ioutil.ReadAll(r.Body); err != nil {
http.Error(w, err.Error(), 500)
return
}
defer r.Body.Close()
// sleep for some time
resp_time := 1
if response_time != "" {
ms, _ := strconv.ParseFloat(response_time, 64)
resp_time = (int)(ms * 1000)
}
time.Sleep(time.Duration(resp_time) * time.Millisecond)
// parepare response
status := 200
body := ""
w.Header().Set("Content-Type", "text/plain")
w.Header().Set("Content-Length", strconv.Itoa(len(body)))
w.WriteHeader(status)
w.Write([]byte(body))
}
func main() {
http.HandleFunc("/", connHandler)
if err := http.ListenAndServe(":server_port", nil); err != nil {
log.Fatal("ListenAndServe: ", err)
}
}
client 端
客户端需要构建全局client，完整读 response body，并关闭body
package main
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"log"
"net/http"
"time"
)
var (
httpClient *http.Client
)
const (
MaxIdleConnections int = 20
RequestTimeout int = 30
)
// init HTTPClient
func init() {
httpClient = createHTTPClient()
}
// createHTTPClient for connection re-use
func createHTTPClient() *http.Client {
client := &http.Client{
Transport: &http.Transport{
MaxIdle ConnsPerHost: MaxIdleConnections,
},
Timeout: time.Duration(RequestTimeout) * time.Second,
}
return client
}
func conn_reuse_post(conn_reuse_times int) {
var endPoint string = "http://server_ip:server_port/"
data := []byte{}
// fill data
for i := 0; i < conn_reuse_times; i++ {
// use global httpClient to send request
resp, err := httpClient.Post(endPoint, "application/x-www-form-urlencoded", bytes.NewBuffer([]byte(data)))
fmt.Println(resp)
if err != nil {
log.Println("err", err)
return
}
io.Copy(ioutil.Discard, resp.Body) // <= NOTE
resp.Body.Close() // <= NOTE
}
}
func main() {
conn_reuse_post(5)
}
