title: Socket.io with multiple Node.js hosts, emit to all clients
body: <p>I am new to Socket.io and trying to get my head around the best approach to solve this issue. </p>
  
  <p>We have four instances of a Node.js app running behind a load balancer. </p>
  
  <p>What I am trying to achieve is for another app to POST some data to the load balancer URL which will hand if off to one of the instances. </p>
  
  <p>The receiving instance will store the data, then use Socket.io to emit the data to the connected clients. </p>
  
  <p>The issue is that browser/client can only be connected to a single instance at one time. </p>
  
  <p>I am trying to determine if there is a way to emit to all clients at once?</p>
  
  <p>Or have the clients connect to multiple servers using io.connect?</p>
  
  <p>Or is this a case for Redis?</p>