http及websocket性能对比
·2min·李岩
从过往的经历中来看，使用websocket作为http协议的替代似乎是一种潮流。websocket以其小包头、全双工的优势，弥补了http协议的性能上的缺陷。对于长链接需求，完全可以在初始化时创建websocket连接，在业务交互时直接进行通信，使得通信过程更加流畅。相信在基于Quic的http3协议走向成熟应用前，websocket在性能上都具有优势。本文以golang语言为基础，构造场景进行两种协议的性能对比。
场景
在服务端分别启动了http服务及websocket服务，返回所接受到的信息。构造BenchmarkHttp、BenchmarkWS进行请求，发送递增字符串。
代码
// server.go
/*
golang中使用的是http1.1协议，默认为长链接。仅第一次发送请求时进行握手。
*/
package main
import (
"flag"
"fmt"
"io"
"log"
"net/http"
"sync"
"github.com/gorilla/websocket"
)
var ws_addr = flag.String("ws_addr", "localhost:9080", "websocket http service address")
var http_addr = flag.String("http_addr", "localhost:9090", "http address address")
var upgrader = websocket.Upgrader{} // use default options
func ws_echo(w http.ResponseWriter, r *http.Request) {
c, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Print("upgrade:", err)
return
}
defer c.Close()
for {
mt, message, err := c.ReadMessage()
if err != nil {
log.Println("read:", err)
break
}
log.Printf("recv: %s", message)
err = c.WriteMessage(mt, message)
if err != nil {
log.Println("write:", err)
break
}
}
}
func http_echo(w http.ResponseWriter, req *http.Request) {
req.ParseForm()
echo_data := req.Form.Get("echo")
fmt.Println(echo_data)
io.WriteString(w, echo_data)
return
}
func start_websocket() {
http.HandleFunc("/ws_echo", ws_echo)
log.Fatal(http.ListenAndServe(*ws_addr, nil))
}
func start_http() {
http.HandleFunc("/http_echo", http_echo)
log.Fatal(http.ListenAndServe(*http_addr, nil))
}
func main() {
flag.Parse()
log.SetFlags(0)
wg := sync.WaitGroup{}
wg.Add(2)
go start_websocket()
go start_http()
wg.Wait()
}
// web_test.go
package main
import (
"fmt"
"io/ioutil"
"net/http"
"net/url"
"strconv"
"testing"
"github.com/gorilla/websocket"
)
func BenchmarkHttp(b *testing.B) {
client := &http.Client{}
for i := 0; i < b.N; i++ {
i_str := strconv.Itoa(i)
req, err := http.NewRequest(http.MethodGet, "http://localhost:9090/http_echo?echo="+i_str, nil)
if err != nil {
fmt.Println("create new request failed", err.Error())
return
}
//b.ResetTimer()
resp, err := client.Do(req)
if err != nil {
fmt.Println("got http request error", err.Error())
return
}
_, _ = ioutil.ReadAll(resp.Body)
//fmt.Println(string(body))
}
}
func BenchmarkWs(b *testing.B) {
addr := "localhost:9080"
u := url.URL{Scheme: "ws", Host: addr, Path: "/ws_echo"}
c, _, err := websocket.DefaultDialer.Dial(u.String(), nil)
if err != nil {
fmt.Println("Error, create websocket connect failed")
return
}
for i := 0; i < b.N; i++ {
err = c.WriteMessage(websocket.TextMessage, []byte(strconv.Itoa(i)))
if err != nil {
fmt.Println("write ws message failed, ", err.Error())
continue
}
_, message, err := c.ReadMessage()
if err != nil {
fmt.Println("Error, recv message failed")
fmt.Println(string(message))
continue
}
//fmt.Println(string(message))
}
err = c.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, ""))
c.Close()
}
结果
go test -bench=. -benchtime=3s -run=none
BenchmarkHttp-8 57764 62737 ns/op
BenchmarkWs-8 101538 36740 ns/op
PASS
ok web_perf 8.850s
从结果中可以直观的看到，websocket协议有明显的性能优势。
问题结论
上次提出了两个问题，后来经过测试，有了结论。这里贴一下。
- 单个goroutine 崩溃时，该进程内其他的goroutine也会崩溃。通常的做法是使用一层wrapper，进行recover获取及现场、日志等保存；
- golang中线程的实现，runtime中，初始化时会申请内核态线程；见
runtime/proc.go；
问题思考
- http1.0, http1.1, http2.0, http3.0, websocket, quic协议的介绍；
- rpc调用与websocket通信之间的网络延时对比；