title: Pub/sub implementation in nodeJS
body: <p>I've been playing around with different publish/subscribe implementations for nodeJS and was wondering which one would be best for a specific application. The requirements of the application involve real-time syncing of objects in multi-channel, multi-user 3D environments.</p>
  
  <p>I started off using socket.io, created a basic array of channels, and when users send messages, it loops through the users in that channel and sends a message to the users' client. This worked well, and I had no problems with it.</p>
  
  <p>For object persistence, I added Redis support using node_redis. Then I replaced the client.send loop on the array of channels with Redis pub/sub as a layer of abstraction. But I noticed that I needed to create a new Redis client for each user that made a subscription.  And I still needed to store socket.io client information to send messages to on publish. How scalable is that? Are there other (better) implementations or further optimizations I could make? What would you do?</p>