apache/hadoop · error · IllegalArgumentException

taskType for {} is neither MAP nor REDUCE: {}

Error message

taskType for {} is neither MAP nor REDUCE: {}

What it means

Error "taskType for {} 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:634

        return new ReduceTaskAttemptInfo
          (state, taskInfo, 0, 0, reduceTime, allSplitVectors);
      } else {
        if (shuffleDone <= 0) {
          shuffleDone = startTime;
        }
        if (mergeDone <= 0) {
          mergeDone = finishTime;
        }
        long shuffleTime = shuffleDone - startTime;
        long mergeTime = mergeDone - shuffleDone;
        long reduceTime = finishTime - mergeDone;
        reduceTime = sanitizeTaskRuntime(reduceTime, loggedAttempt.getAttemptID());
        
        return new ReduceTaskAttemptInfo(state, taskInfo, shuffleTime,
            mergeTime, reduceTime, allSplitVectors);
      }
    } else {
      throw new IllegalArgumentException("taskType for "
          + loggedTask.getTaskID() + " is neither MAP nor REDUCE: "
          + loggedTask.getTaskType());
    }
  }

  private TaskInfo getTaskInfo(LoggedTask loggedTask) {
    if (loggedTask == null) {
      return new TaskInfo(0, 0, 0, 0, 0, 0);
    }
    List<LoggedTaskAttempt> attempts = loggedTask.getAttempts();

    long inputBytes = -1;
    long inputRecords = -1;
    long outputBytes = -1;
    long outputRecords = -1;
    long heapMegabytes = -1;
    ResourceUsageMetrics metrics = new ResourceUsageMetrics();

View on GitHub (pinned to 2add963021)

Solutions

1. Check the trace record for this task; its taskType must be MAP or REDUCE.

When it happens

Trigger: ZombieJob.getTaskInfo is asked for a task whose type is neither MAP nor REDUCE (e.g. setup/cleanup), which is unsupported.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/debadebf89345909. Report an issue: GitHub.