This is simple node.js application with Express.js 4.x, Socket.IO 1.x and socket.io-redis.
$ redis-server &
$ git clone https://github.com/stoshiya/socket.io-redis-sample.git
$ cd socket.io-redis-sample
$ npm install
$ PORT=3000 node app.js &
$ PORT=3001 node app.js &
MIT