Tearing my hair out with this one... has anyone managed to scale Socket.IO to multiple worker processes spawned by Node.js's cluster module?
Lets say I have the following on four worker processes (pseudo):
// on the server
var express = require('express');
var server = express();
var socket = require('socket.io');
var io = socket.listen(server);
// socket.io
io.set('store', new socket.RedisStore);
// set-up connections...
io.sockets.on('connection', function(socket) {
socket.on('join', function(rooms) {
rooms.forEach(function(room) {
socket.join(room);
});
});
socket.on('leave', function(rooms) {
rooms.forEach(function(room) {
socket.leave(room);
});
});
});
// Emit a message every second
function send() {
io.sockets.in('room').emit('data', 'howdy');
}
setInterval(send, 1000);
And on the browser...
// on the client
socket = io.connect();
socket.emit('join', ['room']);
socket.on('data', function(data){
console.log(data);
});
The problem: Every second, I'm receiving four messages, due to four separate worker processes sending the messages.
How do I ensure the message is only sent once?