apache/hadoop · warning · NotFoundException

taskid {tid} not found or invalid

Error message

taskid {tid} not found or invalid

What it means

Returned as HTTP 404 by the JobHistoryServer REST task endpoints (e.g. GET /ws/v1/history/mapreduce/jobs/{jobid}/tasks/{taskid}/counters) when MRApps.toTaskID(tid) yields null, i.e. the {taskid} path segment cannot be converted into a TaskId object. This is the guard for unparseable or invalid task identifiers before the job's task map is consulted. Note: because TaskID.forName uses a strict regex (task_<jobTimestamp>_<jobId>_[m|r]_<taskNum>), many malformed ids also surface as 400/500 from the parser; this 404 covers the null-return path and ids that parse structurally but do not belong to the job.

Source

Thrown at hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/main/java/org/apache/hadoop/mapreduce/v2/hs/webapp/HsWebServices.java:389

    Task task = AMWebServices.getTaskFromTaskIdString(tid, job);
    return new TaskInfo(task);

  }

  @GET
  @Path("/mapreduce/jobs/{jobid}/tasks/{taskid}/counters")
  @Produces({ MediaType.APPLICATION_JSON + "; " + JettyUtils.UTF_8,
      MediaType.APPLICATION_XML + "; " + JettyUtils.UTF_8 })
  public JobTaskCounterInfo getSingleTaskCounters(
      @Context HttpServletRequest hsr, @PathParam("jobid") String jid,
      @PathParam("taskid") String tid) {

    init();
    Job job = AMWebServices.getJobFromJobIdString(jid, ctx);
    checkAccess(job, hsr);
    TaskId taskID = MRApps.toTaskID(tid);
    if (taskID == null) {
      throw new NotFoundException("taskid " + tid + " not found or invalid");
    }
    Task task = job.getTask(taskID);
    if (task == null) {
      throw new NotFoundException("task not found with id " + tid);
    }
    return new JobTaskCounterInfo(task);
  }

  @GET
  @Path("/mapreduce/jobs/{jobid}/tasks/{taskid}/attempts")
  @Produces({ MediaType.APPLICATION_JSON + "; " + JettyUtils.UTF_8,
      MediaType.APPLICATION_XML + "; " + JettyUtils.UTF_8 })
  public TaskAttemptsInfo getJobTaskAttempts(@Context HttpServletRequest hsr,
      @PathParam("jobid") String jid, @PathParam("taskid") String tid) {

    init();
    TaskAttemptsInfo attempts = new TaskAttemptsInfo();
    Job job = AMWebServices.getJobFromJobIdString(jid, ctx);

View on GitHub (pinned to 2add963021)

Solutions

1. Use a task id of the exact form task_<timestamp>_<seq>_[m|r]_<n> taken from the job's task listing
2. List tasks first (GET .../tasks) and copy the id field from the response
3. Do not substitute attempt ids; attempts live under .../tasks/{taskid}/attempts

Example fix

# before
curl "http://jhs:19888/ws/v1/history/mapreduce/jobs/$JID/tasks/attempt_1400000000000_0001_m_000000_0/counters"

# after
curl "http://jhs:19888/ws/v1/history/mapreduce/jobs/$JID/tasks/task_1400000000000_0001_m_000000/counters"

private static final Pattern TASK_ID =
  Pattern.compile("task_\\d+_\\d+_[mr]_\\d+");
boolean isValidTaskId(String tid) {
  return tid != null && TASK_ID.matcher(tid).matches()
      && tid.startsWith("task_" + jobIdSubstring(jid)); // embedded job must match
}

boolean isRequestableTaskId(String tid) {
  return tid != null && TASK_ID.matcher(tid).matches();
}

try { counters = jhsClient.getTaskCounters(jid, tid); }
catch (NotFoundException e) { /* unknown or invalid task id for this job */ }

When it happens

Trigger: GET /ws/v1/history/mapreduce/jobs/job_1400000000000_0001/tasks/task_9999999999999_0001_m_0/counters — a task id whose embedded job portion or format is wrong (e.g. attempt_... passed instead of task_..., missing trailing task number).

Common situations: Passing an attempt id (attempt_...) where a task id (task_...) is required; Cutting the id short or including the '_m_'/'_r_' literal from documentation examples; Mixing ids from a different job or cluster (valid shape, unknown to this job)

Related errors

• task not found with id {tid}
• unable to load configuration for job: {jid}
• taskid {} not found or invalid
• task not found with id {}
• startedTimeEnd must be greater than 0

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/867306b533244577. Report an issue: GitHub.