public void onContainersAllocated(List<Container> containers) {
   L.info("onContainersAllocated: # containers=" + containers.size());
   for (Container container : containers) {
     try {
       launchWorkerNode(container);
     } catch (Exception e) {
       L.error("Error launching worker-node: container-id=" + container.getId() + " " + e);
       die();
     }
   }
 }