apache/hadoop · error · IllegalArgumentException

taskType is neither MAP nor REDUCE: {}

Error message

taskType is neither MAP nor REDUCE: {}

What it means

Error "taskType is neither MAP nor REDUCE: {}" thrown in apache/hadoop.

Source

Thrown at hadoop-tools/hadoop-rumen/src/main/java/org/apache/hadoop/tools/rumen/ZombieJob.java:733

                                               taskNumber, taskAttemptNumber));
      TaskAttemptInfo tai
        = new MapTaskAttemptInfo(state, taskInfo, runtime, null);
      return tai;
    } else if (taskType == TaskType.REDUCE) {
      State state = State.SUCCEEDED;
      long shuffleTime = 0;
      long sortTime = 0;
      long reduceTime = 0;

      // TODO make up state
      // state = makeUpState(taskAttemptNumber, job.getReducerTriesToSucceed());
      reduceTime = makeUpReduceRuntime(state);
      TaskAttemptInfo tai = new ReduceTaskAttemptInfo
        (state, taskInfo, shuffleTime, sortTime, reduceTime, null);
      return tai;
    }

    throw new IllegalArgumentException("taskType is neither MAP nor REDUCE: "
        + taskType);
  }

  private long makeUpReduceRuntime(State state) {
    long reduceTime = 0;
    for (int i = 0; i < 5; i++) {
      reduceTime = doMakeUpReduceRuntime(state);
      if (reduceTime >= 0) {
        return reduceTime;
      }
    }
    return 0;
  }

  private long doMakeUpReduceRuntime(State state) {
    long reduceTime;
    try {
      if (state == State.SUCCEEDED) {

View on GitHub (pinned to 2add963021)

Solutions

1. Fix the trace so the taskType is MAP or REDUCE.

When it happens

Trigger: A task in the simulated job has a type that is neither MAP nor REDUCE when building the zombie task info.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/e7c3671525d754b5. Report an issue: GitHub.