code: public synchronized void setJobPriority(JobID jobid,
                                                String priority)
                                                  throws IOException {
      JobInProgress job = jobs.get(jobid);
      if (null == job) {
          LOG.info("setJobPriority(): JobId " + jobid.toString()
              + " is not a valid job");
          return;
      }
      checkAccess(job, QueueManager.QueueOperation.ADMINISTER_JOBS);
      JobPriority newPriority = JobPriority.valueOf(priority);
      setJobPriority(jobid, newPriority);
    }
docs: Set the priority of a job
  @param jobid id of the job
  @param priority new priority of the job