code: public void logReduceTaskKilled(TaskAttemptID taskAttemptId, long timestamp,
                                    String hostName, String error,
                                    String taskType) {
      if (disableHistory) {
        return;
      }
  
      JobID id = taskAttemptId.getJobID();
      if (!this.jobId.equals(id)) {
        throw new RuntimeException("JobId from task: " + id +
                                   " does not match expected: " + jobId);
      }
  
      if (null != writers) {
        log(writers, RecordTypes.ReduceAttempt,
            new Keys[]{  Keys.TASK_TYPE, Keys.TASKID,
                         Keys.TASK_ATTEMPT_ID, Keys.TASK_STATUS,
                         Keys.FINISH_TIME, Keys.HOSTNAME,
                         Keys.ERROR },
            new String[]{ taskType,
                          taskAttemptId.getTaskID().toString(),
                          taskAttemptId.toString(),
                          Values.KILLED.name(),
                          String.valueOf(timestamp),
                          hostName, error });
      }
    }
docs: Log killed reduce task attempt.
  
  @param taskAttemptId task attempt id
  @param timestamp time stamp when task failed
  @param hostName host name of the task attempt.
  @param error error message of the task.
  @param taskType Whether the attempt is cleanup or setup or reduce