I\'ve been searching around looking for help on setting up a multi-server cluster for a Node.js Socket.IO install. This is what I am trying to do:
The answer to this question is that you must set up a single Redis server that is either outside your SocketIO cluster - and have all nodes connect to it.
Then you simply add this at the top of your code and it just works magically without any issues.
var io = require('socket.io')(server);
var redis = require('socket.io-redis');
io.adapter(redis({ host: 'localhost', port: 6379 }));