Node.js使用redis集群进行Socket.IO扩展

目前,我面临的任务是必须使用Amazon EC2扩展Node.js应用程序.根据我的理解,这样做的方法是让每个子服务器使用集群使用所有可用进程,并具有粘性连接,以确保“记住”连接到服务器的每个用户关于他们当前数据的工作者以前的会议.

完成此操作之后,我所知道的下一个最佳移动是根据需要部署尽可能多的服务器,并使用nginx在所有服务器之间进行负载平衡,再次使用粘性连接来了解每个用户数据所在的“子”服务器.

因此,当用户连接到服务器时,会发生什么？

客户端连接 – >查找/选择服务器 – >查找/选择流程 – > Socket.IO握手/连接等

如果没有,请允许我更好地理解这个负载平衡任务.我也不明白redis在这种情况下的重要性.

下面是我用来在一台机器上使用所有CPU的代码,用于单独的Node.js进程：

var express = require('express');
cluster = require('cluster'),net = require('net'),sio = require('socket.io'),sio_redis = require('socket.io-redis');

var port = 3502,num_processes = require('os').cpus().length;

if (cluster.isMaster) {
// This stores our workers. We need to keep them to be able to reference
// them based on source IP address. It's also useful for auto-restart,// for example.
var workers = [];

// Helper function for spawning worker at index 'i'.
var spawn = function(i) {
    workers[i] = cluster.fork();

    // Optional: Restart worker on exit
    workers[i].on('exit',function(worker,code,signal) {
        console.log('respawning worker',i);
        spawn(i);
    });
};

// Spawn workers.
for (var i = 0; i < num_processes; i++) {
    spawn(i);
}

// Helper function for getting a worker index based on IP address.
// This is a hot path so it should be really fast. The way it works
// is by converting the IP address to a number by removing the dots,// then compressing it to the number of slots we have.
//
// Compared against "real" hashing (from the sticky-session code) and
// "real" IP number conversion,this function is on par in terms of
// worker index distribution only much faster.
var worker_index = function(ip,len) {
    var s = '';
    for (var i = 0,_len = ip.length; i < _len; i++) {
        if (ip[i] !== '.') {
            s += ip[i];
        }
    }

    return Number(s) % len;
};

// Create the outside facing server listening on our port.
var server = net.createServer({ pauSEOnConnect: true },function(connection) {
    // We received a connection and need to pass it to the appropriate
    // worker. Get the worker for this connection's source IP and pass
    // it the connection.
    var worker = workers[worker_index(connection.remoteAddress,num_processes)];
    worker.send('sticky-session:connection',connection);
}).listen(port);
} else {
// Note we don't use a port here because the master listens on it for us.
var app = new express();

// Here you might use middleware,attach routes,etc.

// Don't expose our internal server to the outside.
var server = app.listen(0,'localhost'),io = sio(server);

// Tell Socket.IO to use the redis adapter. By default,the redis
// server is assumed to be on localhost:6379. You don't have to
// specify them explicitly unless you want to change them.
io.adapter(sio_redis({ host: 'localhost',port: 6379 }));

// Here you might use Socket.IO middleware for authorization etc.

console.log("Listening");
// Listen to messages sent from the master. Ignore everything else.
process.on('message',function(message,connection) {
    if (message !== 'sticky-session:connection') {
        return;
    }

    // Emulate a connection event on the server by emitting the
    // event with the connection the master sent us.
    server.emit('connection',connection);

    connection.resume();
});
}