apache/hadoop · error · IllegalArgumentException

TaskId string : ${str} is not properly formed Reason: ${m}

Error message

TaskId string : ${str} is not properly formed
Reason: ${m}

What it means

Error "TaskId string : ${str} is not properly formed Reason: ${m}" thrown in apache/hadoop.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/TaskID.java:253

   *
   * @param str the target string
   * @return constructed TaskID object or null if the given String is null
   * @throws IllegalArgumentException if the given string is malformed
   */
  public static TaskID forName(String str) 
    throws IllegalArgumentException {
    if(str == null)
      return null;
    Matcher m = taskIdPattern.matcher(str);
    if (m.matches()) {
      return new org.apache.hadoop.mapred.TaskID(m.group(1),
          Integer.parseInt(m.group(2)),
          CharTaskTypeMaps.getTaskType(m.group(3).charAt(0)),
          Integer.parseInt(m.group(4)));
    }
    String exceptionMsg = "TaskId string : " + str + " is not properly formed" +
        "\nReason: " + m.toString();
    throw new IllegalArgumentException(exceptionMsg);
  }
  /**
   * Gets the character representing the {@link TaskType}.
   *
   * @param type the TaskType
   * @return the character
   */
  public static char getRepresentingCharacter(TaskType type) {
    return CharTaskTypeMaps.getRepresentingCharacter(type);
  }
  /**
   * Gets the {@link TaskType} corresponding to the character.
   *
   * @param c the character
   * @return the TaskType
   */
  public static TaskType getTaskType(char c) {
    return CharTaskTypeMaps.getTaskType(c);

View on GitHub (pinned to 2add963021)

Solutions

1. Provide a properly formed task ID string to forName(); the message includes the parse reason.

When it happens

Trigger: Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/TaskID.java:253 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/55c3c830a9ef7b0a. Report an issue: GitHub.