在高并发Http服务中， 更新应用时会出现短暂的connect resuse和部分http请求数据丢失问题。这样在有些服务中是不可容忍的，所有需要Http服务做平滑重启处理。
1. 开源解决方案
2. 方案测试
1. grace
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| package main
import (
"fmt"
"net/http"
"os"
"time"
"github.com/facebookgo/grace/gracehttp"
)
var startTime time.Time
type HttpHandle int
func (h HttpHandle) ServeHTTP(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Second * 10)
w.Write([]byte(fmt.Sprintf("pid:%v, startTime:%v\n", os.Getpid(), startTime)))
}
func main() {
startTime = time.Now()
gracehttp.Serve(
&http.Server{Addr: ":7070", Handler: new(HttpHandle)},
)
}
|
测试结果：
2. endless
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| package main
import (
"fmt"
"net/http"
"os"
"time"
"github.com/fvbock/endless"
)
var startTime time.Time
type HttpHandle int
func (h HttpHandle) ServeHTTP(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Second * 10)
w.Write([]byte(fmt.Sprintf("pid:%v, startTime:%v\n", os.Getpid(), startTime)))
}
func main() {
startTime = time.Now()
endless.ListenAndServe(":7070", new(HttpHandle))
}
|
测试结果：
3. overseer
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| package main
import (
"fmt"
"net/http"
"os"
"time"
"github.com/jpillora/overseer"
)
var startTime time.Time
type HttpHandle int
func (h HttpHandle) ServeHTTP(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Second * 10)
w.Write([]byte(fmt.Sprintf("pid:%v, startTime:%v\n", os.Getpid(), startTime)))
}
func realMain(state overseer.State){
startTime = time.Now()
http.Serve(state.Listener, new(HttpHandle))
}
func main() {
overseer.Run(overseer.Config{
Program: realMain,
Address: ":7070",
})
}
|
测试结果：
3. 选择
从上面测试可以看出三个软件都能满足Http服务平滑启动的功能；
grace endless功能实现方式：两个都是以开启子进程来加载新可执行程序， 父进程处理完成当前请求后退出；
overseer功能实现方式：启动后会有两个进程[管理进程/功能进程]，重启过程中， 管理进程后启动新子进程来执行新可执行程序， 旧子进程处理完成当前请求后退出；
overseer能够兼容进程管理软件(systemd, upstart, supervisor, etc)，而grace endless不支持