title: Spark Clusters: worker info doesn't show on web UI
body: <p>I have installed spark standalone on a set of clusters. And I tried to launch clusters through the cluster launch script. I have added cluster's IP address into conf/slaves file. The master connects to all slaves through password-less ssh. 
  After running <code>./bin/start-slaves.sh</code> script, I get the following message:   </p>
  
  <blockquote>
    <p>starting org.apache.spark.deploy.worker.Worker, logging to /root/spark-0.8.0-incubating/bin/../logs/spark-root-org.apache.spark.deploy.worker.Worker-1-jbosstest2.out </p>
  </blockquote>
  
  <p>But the webUI of the master (localhost:8080) is not showing any information about the worker. But when I add localhost entry onto my conf/slaves file the worker info of localhost is shown.</p>
  
  <p>There are no error messages, the message on terminal says the worker is started, but the WebUI is not showing any workers. </p>