apache/hadoop · error · IOException

Undefined job output-path

Error message

Undefined job output-path

What it means

Error "Undefined job output-path" thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/FileOutputFormat.java:248

    String name = conf.get(JobContext.TASK_OUTPUT_DIR);
    return name == null ? null: new Path(name);
  }

  /**
   * Helper function to create the task's temporary output directory and 
   * return the path to the task's output file.
   * 
   * @param conf job-configuration
   * @param name temporary task-output filename
   * @return path to the task's temporary output file
   * @throws IOException
   */
  public static Path getTaskOutputPath(JobConf conf, String name) 
  throws IOException {
    // ${mapred.out.dir}
    Path outputPath = getOutputPath(conf);
    if (outputPath == null) {
      throw new IOException("Undefined job output-path");
    }

    OutputCommitter committer = conf.getOutputCommitter();
    Path workPath = outputPath;
    TaskAttemptContext context = 
      new TaskAttemptContextImpl(conf,
                                 TaskAttemptID.forName(conf.get(
                                     JobContext.TASK_ATTEMPT_ID)));
    if (committer instanceof FileOutputCommitter) {
      workPath = ((FileOutputCommitter)committer).getWorkPath(context,
                                                              outputPath);
    }
    
    // ${mapred.out.dir}/_temporary/_${taskid}/${name}
    return new Path(workPath, name);
  } 

  /**

View on GitHub (pinned to 2add963021)

Solutions

1. Define the job output path via FileOutputFormat.setOutputPath or mapreduce.output.fileoutputformat.outputdir before calling getWorkOutputPath.

When it happens

Trigger: Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/FileOutputFormat.java:248 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/eaa8a71ee4a90f93. Report an issue: GitHub.