對Websocket進行負載均衡

http {
    // ...省略

    map $http_upgrade $connection_upgrade {
        default upgrade;
        ''      close;
    }

    upstream websocketCluster {
        ip_hash;
        server 127.0.0.1:6181;
        server 127.0.0.1:6182;
    }

    server {
        listen       80;
        proxy_pass   httpCluster;
        #域名可以有多個，用空格隔開
 

        server_name  localhost 127.0.0.1;

        location /chat {
        # proxy_pass 127.0.0.1:6181
        proxy_pass websocketCluster

        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

        proxy_http_version 1.1
 
;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        }
    }

    // ...省略
}

socket.io負載均衡

###伺服器
var chat = io.of('/chat');
chat.on('connection', function(socket){});
###客戶端
var socket = require('socket.io-client')('http://localhost/chat');

由於伺服器有很多虛擬主機需要代理，想通過/chat/路徑對websocket分發，socket.io-client連線時一直無法連線。

#檢視socket.io詳細DEBUG資訊
DEBUG=* node socketClient.js

engine.io-client:polling polling +0ms
  engine.io-client:polling-xhr xhr poll +0ms
  engine.io-client:polling-xhr xhr open GET: http://localhost/socket.io/?EIO=3&transport=polling&t=1445484908552-6&b64=1&sid=dwJSvjOsMPxKwnP9AAAB +0ms

var io = require('socket.io')(httpServer,{
   "path":"/chat",         //客戶端和伺服器端都指定連線的Url
  "serveClient": false });

或者將Nginx的路徑改為/socket.io/就好了。

參照