private void openJobBrowser() {
   if (allInstancesUp() == false) {
     JOptionPane.showMessageDialog(this, "Sorry, cluster is not (completely) up");
   }
   try {
     EC2Agent agent = new EC2Agent();
     Cluster cluster = agent.getRunningInstances(false);
     cluster.assignRoles();
     if (cluster.getJobTracker() != null) {
       UtilUI.openBrowser(this, "http://" + cluster.getJobTracker().getDnsName() + ":50030");
     }
   } catch (Exception e) {
     e.printStackTrace(System.out);
   }
 }
 private boolean allInstancesUp() {
   EC2Agent agent = new EC2Agent();
   Cluster cluster = agent.getRunningInstances(true);
   return cluster.size() == agent.getClusterSize()
       && cluster.getInitializedCount() == agent.getClusterSize();
 }