title: maximum concurrently open rooms in socket.io
body: <p>I am in the process of implementing a chat server using node.js, mongodb, socket.io and express. What I would like to know is whether there's a limit on the maximum no. of concurrently open rooms for socket.io multi-room chat. </p>
  
  <p>Also, is there a maximum on no. of users per room.</p>