code: public void startJob(String targetCluster) throws ExecutionException {
          getConnection(targetCluster).setJobInProgress(true);
          logger.info("a new job has been started in cluster [" + targetCluster + "]");
      }
docs: This method start a work for a connections.
  
  @param targetCluster the connections cluster name.
  @throws ExecutionException if the work can not start.