title: Inject Client-Ids for fluent server change
body: <p>I am currently redirecting the socket io through a custom proxy. The server it actually gets send to changes from time to time. The &quot;new&quot; server is notfied that a client will connect/swap to it before it connects/swaps. The only issue is that this leads to the client timing out and reconnecting, which works, but takes 2 seconds that I dont want to client to wait on switch. I do not want the client to know that the server change so somehow i have to make the server to add the upcomming client/socket id to its internal list.
  How could I achieve this?</p>
  <p>Ive looked at the socket.io-adapter, but I wasn't sure if that is only for rooms/or if there is an easier way to do it</p>