How to make a chat cluster?

Question

Node.js

I am writing a chat that will be with a large number of connections.
The chat requires checking users for a ban.
In order to keep many connections I use cluster

var cluster = require('cluster'),
    numCPUs = require('os').cpus().length;

if (cluster.isMaster) {
    for (var i = 0; i < numCPUs; i++) {
        cluster.fork();
    }
}

if (cluster.isWorker) {
    var io = require('socket.io').listen(2001);

    io.sockets.on('connection', function (socket) {
        console.log('connected to worker id ', cluster.worker.id);
    });
    io.sockets.on('user-message', function (socket) {
        // здесь не знаю что делать
    });
}

After the user sends a message, I need to check if the user is banned.
I imagined that there would be a common object

USERS = {
 1: {id: 1, banned: false},
 2: {id: 3, banned: true}
 ......
}

and at each event check it for a ban.
How to do it and where to store this object?
There is such an idea - to store it in the master and from the "worker" through process.send (); send everything that came to the socket, in the same place, in the master, check and broadcast to everyone.

Answer 1

Wang problems with handshake :) I advise you to immediately take a look at https://github.com/indutny/sticky-session
On the issue, store in Redis.