title: How to use socket.io-redis with multiple servers?
body: <p>i have following code on two machines</p>
  
  <pre><code> var server       = require('http').createServer(app);
      io               = require('socket.io')(server);
      var redisAdapter = require('socket.io-redis');
      io.adapter(redisAdaptebr({host: config.redis.host, port: config.redis.port}));
      server.listen(config.port, function () {
  </code></pre>
  
  <p>and I store socket.id of every client connected to these two machines on central db, ID of sockets is being saved and event sending on same server works flawlessly, but when I try to send message to the socket of other server it doesn't work..</p>
  
  <pre><code>subSocket = io.sockets.connected[userSocketID];
     subSocket.emit('hello',{a:'b'})
  </code></pre>
  
  <ol>
  <li>How can i know that redis is wokring good.</li>
  <li>How to send message to socket connected on another server.</li>
  </ol>