Socket.io无法连接nginx node.js php app

我试图用PHP app和node.js一起运行nginx(这部分工作正常).另外我想将socket.io添加到此设置中,但不幸的是我无法在客户端和服务器之间建立连接(看起来像连接超时？).

server.js

var app = require("http"),redis = require("redis"),io = require('socket.io')(app);


io.sockets.on( 'connection',function( client ) {
    console.log( "New client !" );

    io.sockets.emit('msg',{ msg: 'Foo bar' } );
});

app.createServer().listen(3000);
console.log("Server running at 127.0.0.1:3000");

client.js