private void killJob() {
    boolean needToKillJob = false;
    synchronized(this) {
      if (rj != null && !jobKilled) {
        jobKilled = true;
        needToKillJob = true;
      }
    }
    if (needToKillJob) {
      try {
        rj.killJob();
      } catch (Exception e) {
        LOG.warn("failed to kill job " + rj.getID(), e);
      }
    }
  }
Given a Hive Configuration object - generate a command line fragment for passing such
configuration information to ExecDriver.
ql/src/java/org/apache/hadoop/hive/ql/exec/mr/ExecDriver.java