The start_server utility is a superdaemon for hot-deploying server programs.Let's try.
Environment: EC2 AMI ID: Amazon Linux AMI 2015.09 (HVM), SSD Volume Type - ami-9a2fb89a
Go Sample app
Install Go
Start app with start_server
No error with graceful restart?
Set Nginx for Reverse Proxy
Nginx is necessary for safe connection from the HTTP cliant. Nginx Reverse Proxy makes re-handshake for the backend.
Benchmark
start_server support UNIX domain socket. Let's Benchmark Port vs UNIX domain socket.
Instance type: c4.xlarge
Benchmark command.
Tips
How to stop start_server
Install Go
$ sudo yum -y install golang $ go version go version go1.4.2 linux/amd64 $ mkdir ~/gocode $ echo 'export GOPATH=$HOME/gocode' >> ~/.bashrc $ source $HOME/.bashrcInstall go-server-starter
# go get github.com/lestrrat/go-server-starter/cmd/start_server # $GOPATH/bin/start_server --version 0.0.2 # $GOPATH/bin/start_server --helpMake sample web app
# mkdir $GOPATH/src/web/
# cd $GOPATH/src/web/
# emacs sample.go
package main
import (
"fmt"
"github.com/lestrrat/go-server-starter/listener"
"log"
"net"
"net/http"
"os"
)
func hello(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "Hello world!")
}
func newHandler() http.Handler {
mux := http.NewServeMux()
mux.HandleFunc("/", hello)
return mux
}
func main() {
var l net.Listener
// check environment variable
if os.Getenv("SERVER_STARTER_PORT") != "" {
listeners, err := listener.ListenAll()
if err != nil {
fmt.Println(err)
return
}
if 0 < len(listeners) {
l = listeners[0]
}
}
// default port
if l == nil {
var err error
l, err = net.Listen("tcp", fmt.Sprintf(":8080"))
if err != nil {
fmt.Println(err)
return
}
}
log.Printf("Start Go HTTP Server")
fmt.Println(http.Serve(l, newHandler()))
}
# go install
# $GOPATH/bin/web
2015/10/26 07:36:23 Start Go HTTP Server
# curl localhost:8080
Hello world!
Start app with start_server
# KILL_OLD_DELAY=5 nohup $GOPATH/bin/start_server --port=8000 --pid-file=$GOPATH/start_server.pid -- $GOPATH/bin/web >> $GOPATH/start_server.log &
# cat $GOPATH/start_server.log
starting new worker 26499
2015/10/26 08:36:55 Start Go HTTP Server
$ curl http://127.0.0.1:8000/
Hello world!
Try to hot-deploy.
# cd $GOPATH/src/web/
# emacs sample.go
fmt.Fprintf(w, "Hello world!")
->
fmt.Fprintf(w, "Hello world!!!!")
# go install
Graceful restart.
# /bin/cat $GOPATH/start_server.pid | xargs kill -HUPCheck log.
# cat $GOPATH/start_server.log received HUP (num_old_workers=TODO) spawning a new worker (num_old_workers=TODO) starting new worker 2618 2015/10/27 02:43:21 Start Go HTTP Server new worker is now running, sending TERM to old workers:2576 sleep 5 secs killing old workers old worker 2576 died, status:512Check result.
$ curl http://127.0.0.1:8000/ Hello world!!!!That's fine.
No error with graceful restart?
Set Nginx for Reverse Proxy
Nginx is necessary for safe connection from the HTTP cliant. Nginx Reverse Proxy makes re-handshake for the backend.
$ sudo yum -y install nginx
$ sudo emacs /etc/nginx/nginx.conf
worker_processes 1;
events {
worker_connections 50000;
}
http {
include mime.types;
access_log off;
upstream app {
server 127.0.0.1:8000 max_fails=10;
server localhost:8000 max_fails=10 backup;
}
server {
location / {
proxy_pass http://app;
proxy_next_upstream error http_502;
}
}
}
$ sudo service nginx start
$ curl http://127.0.0.1/
Hello world!!!!
Run long time ab
$ sudo yum -y install httpd-tools # ab -c 10 -n 200000 http://127.0.0.1/Graceful restart
$ /bin/cat $GOPATH/start_server.pid | xargs kill -HUP $ tail -f $GOPATH/start_server.log received HUP (num_old_workers=TODO) spawning a new worker (num_old_workers=TODO) starting new worker 2766 2015/10/27 02:56:48 Start Go HTTP Server new worker is now running, sending TERM to old workers:2759 sleep 5 secs killing old workers old worker 2759 died, status:512Result from ab
Failed requests: 0
Benchmark
start_server support UNIX domain socket. Let's Benchmark Port vs UNIX domain socket.
Instance type: c4.xlarge
Benchmark command.
# ab -c 100 -n 1000000 http://127.0.0.1/start_server start commands:
Port # KILL_OLD_DELAY=5 nohup $GOPATH/bin/start_server --port=8000 --pid-file=$GOPATH/start_server.pid -- $GOPATH/bin/web >> $GOPATH/start_server.log & UNIX domain socket $ KILL_OLD_DELAY=5 nohup $GOPATH/bin/start_server --path /tmp/app.sock --pid-file=$GOPATH/start_server.pid -- $GOPATH/bin/web >> $GOPATH/start_server.log & $ chmod 777 /tmp/app.sockNginx confs:
Port
upstream app {
server 127.0.0.1:8000;
}
UNIX domain socket
upstream app {
server unix:/tmp/app.sock;
}
Results.
Port Requests per second: 12544.89 [#/sec] (mean) UNIX domain socket Requests per second: 18435.59 [#/sec] (mean)
Tips
How to stop start_server
# /bin/cat $GOPATH/start_server.pid | xargs kill -TERM
# cat $GOPATH/start_server.log received TERM, sending TERM to all workers:2766 worker 2766 died, status:512 exiting
See also.
Server Starter - a superdaemon to hot-deploy server programs
http://www.slideshare.net/kazuho/server-starter-a-superdaemon-to-hotdeploy-server-programs
Fix panic when SERVER_STARTER_PORT is not defined by handlename · Pull Request #3 · lestrrat/go-server-starter
https://github.com/lestrrat/go-server-starter/pull/3
Docker と SO_REUSEPORT を組み合わせてコンテナのHot Deployにチャレンジ - blog.nomadscafe.jp
http://blog.nomadscafe.jp/2015/01/docker-and-so-reuseport-hot-deploy.html
Server::Starterから学ぶhot deployの仕組み - $shibayu36->blog;
http://blog.shibayu36.org/entry/2012/05/07/201556
Top image from John Lord Starter
