node.js - 如何通过 upstart 和 monit 支持多个 nodejs 服务？

Question

我创建了一个 upstart 脚本来守护 node.js 应用程序:

description "app_name"

start on startup
stop on shutdown

script
    export HOME="/home/ubuntu/nodeapp"

    exec sudo -u nodejs /usr/local/bin/node $HOME/app/server.js production 2>>/var/log/app_name.error.log >>/var/log/app_name.log
end script

我的监控脚本如下:

check host app_name with address 127.0.0.1
    start "/sbin/start app_name"
    stop "/sbin/stop app_name"
    if failed port 80 protocol HTTP
        request /ok
        with timeout 5 seconds
        then restart

它工作正常，但现在我想添加 nginx 作为上游的负载均衡器，如下所示:

upstream cluster1 {
  least_conn;
  server 127.0.0.1:8000;
  server 127.0.0.1:8001;
}

server {
    listen 0.0.0.0:80;

    location / {
    proxy_pass http://cluster1;
    }
}

那么我应该如何更改 upstart 和 monit 脚本来支持它呢？

Answer 1

您应该创建三个 monit 检查，一个用于 nginx，一个用于每个 nodejs 实例:

check host nginx with address 127.0.0.1
    start "/sbin/start nginx"
    stop "/sbin/stop nginx"
    if failed port 80 protocol HTTP
        request /ok
        with timeout 5 seconds
        then restart

check host app_name_on_8000 with address 127.0.0.1
    start "/sbin/start app_name_on_8000"
    stop "/sbin/stop app_name_on_8000"
    if failed port 8000 protocol HTTP
        request /ok
        with timeout 5 seconds
        then restart

check host app_name_on_8001 with address 127.0.0.1
    start "/sbin/start app_name_on_8001"
    stop "/sbin/stop app_name_on_8001"
    if failed port 8000 protocol HTTP
        request /ok
        with timeout 5 seconds
        then restart

这将在它们失败时重新启动 nodejs 实例，如果失败或两个 nodejs 实例都关闭，则重新启动 nginx