Java 类org.apache.hadoop.mapreduce.v2.app.job.TaskAttempt 实例源码

private long storedPerAttemptValue
     (Map<TaskAttempt, AtomicLong> data, TaskAttemptId attemptID) {
  TaskId taskID = attemptID.getTaskId();
  JobId jobID = taskID.getJobId();
  Job job = context.getJob(jobID);

  Task task = job.getTask(taskID);

  if (task == null) {
    return -1L;
  }

  TaskAttempt taskAttempt = task.getAttempt(attemptID);

  if (taskAttempt == null) {
    return -1L;
  }

  AtomicLong estimate = data.get(taskAttempt);

  return estimate == null ? -1L : estimate.get();

}

public JobTaskAttemptCounterInfo(TaskAttempt taskattempt) {

    this.id = MRApps.toString(taskattempt.getID());
    total = taskattempt.getCounters();
    taskAttemptCounterGroup = new ArrayList<TaskCounterGroupInfo>();
    if (total != null) {
      for (CounterGroup g : total) {
        if (g != null) {
          TaskCounterGroupInfo cginfo = new TaskCounterGroupInfo(g.getName(), g);
          if (cginfo != null) {
            taskAttemptCounterGroup.add(cginfo);
          }
        }
      }
    }
  }

public TaskAttemptInfo(TaskAttempt ta, TaskType type, Boolean isRunning) {
  final TaskAttemptReport report = ta.getReport();
  this.type = type.toString();
  this.id = MRApps.toString(ta.getID());
  this.nodeHttpAddress = ta.getNodeHttpAddress();
  this.startTime = report.getStartTime();
  this.finishTime = report.getFinishTime();
  this.assignedContainerId = ConverterUtils.toString(report.getContainerId());
  this.assignedContainer = report.getContainerId();
  this.progress = report.getProgress() * 100;
  this.status = report.getStateString();
  this.state = report.getTaskAttemptState();
  this.elapsedTime = Times
      .elapsed(this.startTime, this.finishTime, isRunning);
  if (this.elapsedTime == -1) {
    this.elapsedTime = 0;
  }
  this.diagnostics = report.getDiagnosticInfo();
  this.rack = ta.getNodeRackName();
}

public ReduceTaskAttemptInfo(TaskAttempt ta, TaskType type) {
  super(ta, type, false);

  this.shuffleFinishTime = ta.getShuffleFinishTime();
  this.mergeFinishTime = ta.getSortFinishTime();
  this.elapsedShuffleTime = Times.elapsed(this.startTime,
      this.shuffleFinishTime, false);
  if (this.elapsedShuffleTime == -1) {
    this.elapsedShuffleTime = 0;
  }
  this.elapsedMergeTime = Times.elapsed(this.shuffleFinishTime,
      this.mergeFinishTime, false);
  if (this.elapsedMergeTime == -1) {
    this.elapsedMergeTime = 0;
  }
  this.elapsedReduceTime = Times.elapsed(this.mergeFinishTime,
      this.finishTime, false);
  if (this.elapsedReduceTime == -1) {
    this.elapsedReduceTime = 0;
  }
}

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

  init();
  TaskAttemptsInfo attempts = new TaskAttemptsInfo();
  Job job = getJobFromJobIdString(jid, appCtx);
  checkAccess(job, hsr);
  Task task = getTaskFromTaskIdString(tid, job);

  for (TaskAttempt ta : task.getAttempts().values()) {
    if (ta != null) {
      if (task.getType() == TaskType.REDUCE) {
        attempts.add(new ReduceTaskAttemptInfo(ta, task.getType()));
      } else {
        attempts.add(new TaskAttemptInfo(ta, task.getType(), true));
      }
    }
  }
  return attempts;
}

@GET
@Path("/jobs/{jobid}/tasks/{taskid}/attempts/{attemptid}")
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
public TaskAttemptInfo getJobTaskAttemptId(@Context HttpServletRequest hsr,
    @PathParam("jobid") String jid, @PathParam("taskid") String tid,
    @PathParam("attemptid") String attId) {

  init();
  Job job = getJobFromJobIdString(jid, appCtx);
  checkAccess(job, hsr);
  Task task = getTaskFromTaskIdString(tid, job);
  TaskAttempt ta = getTaskAttemptFromTaskAttemptString(attId, task);
  if (task.getType() == TaskType.REDUCE) {
    return new ReduceTaskAttemptInfo(ta, task.getType());
  } else {
    return new TaskAttemptInfo(ta, task.getType(), true);
  }
}

@Override
protected Collection<TaskAttempt> getTaskAttempts() {
  List<TaskAttempt> fewTaskAttemps = new ArrayList<TaskAttempt>();
  String taskTypeStr = $(TASK_TYPE);
  TaskType taskType = MRApps.taskType(taskTypeStr);
  String attemptStateStr = $(ATTEMPT_STATE);
  TaskAttemptStateUI neededState = MRApps
      .taskAttemptState(attemptStateStr);
  for (Task task : super.app.getJob().getTasks(taskType).values()) {
    Map<TaskAttemptId, TaskAttempt> attempts = task.getAttempts();
    for (TaskAttempt attempt : attempts.values()) {
      if (neededState.correspondsTo(attempt.getState())) {
        fewTaskAttemps.add(attempt);
      }
    }
  }
  return fewTaskAttemps;
}

@Override
public Map<TaskAttemptId, TaskAttempt> getAttempts() {
  readLock.lock();

  try {
    if (attempts.size() <= 1) {
      return attempts;
    }

    Map<TaskAttemptId, TaskAttempt> result
        = new LinkedHashMap<TaskAttemptId, TaskAttempt>();
    result.putAll(attempts);

    return result;
  } finally {
    readLock.unlock();
  }
}

@Override
  public Counters getCounters() {
    Counters counters = null;
    readLock.lock();
    try {
      TaskAttempt bestAttempt = selectBestAttempt();
      if (bestAttempt != null) {
        counters = bestAttempt.getCounters();
      } else {
        counters = TaskAttemptImpl.EMPTY_COUNTERS;
//        counters.groups = new HashMap<CharSequence, CounterGroup>();
      }
      return counters;
    } finally {
      readLock.unlock();
    }
  }

private void handleTaskAttemptCompletion(TaskAttemptId attemptId,
    TaskAttemptCompletionEventStatus status) {
  TaskAttempt attempt = attempts.get(attemptId);
  //raise the completion event only if the container is assigned
  // to nextAttemptNumber
  if (attempt.getNodeHttpAddress() != null) {
    TaskAttemptCompletionEvent tce = recordFactory
        .newRecordInstance(TaskAttemptCompletionEvent.class);
    tce.setEventId(-1);
    String scheme = (encryptedShuffle) ? "https://" : "http://";
    tce.setMapOutputServerAddress(StringInterner.weakIntern(scheme
       + attempt.getNodeHttpAddress().split(":")[0] + ":"
       + attempt.getShufflePort()));
    tce.setStatus(status);
    tce.setAttemptId(attempt.getID());
    int runTime = 0;
    if (attempt.getFinishTime() != 0 && attempt.getLaunchTime() !=0)
      runTime = (int)(attempt.getFinishTime() - attempt.getLaunchTime());
    tce.setAttemptRunTime(runTime);

    //raise the event to job so that it adds the completion event to its
    //data structures
    eventHandler.handle(new JobTaskAttemptCompletedEvent(tce));
  }
}

private void writeBadOutput(TaskAttempt attempt, Configuration conf)
  throws Exception {
  TaskAttemptContext tContext = new TaskAttemptContextImpl(conf, 
      TypeConverter.fromYarn(attempt.getID()));

  TextOutputFormat<?, ?> theOutputFormat = new TextOutputFormat();
  RecordWriter theRecordWriter = theOutputFormat
      .getRecordWriter(tContext);

  NullWritable nullWritable = NullWritable.get();
  try {
    theRecordWriter.write(key2, val2);
    theRecordWriter.write(null, nullWritable);
    theRecordWriter.write(null, val2);
    theRecordWriter.write(nullWritable, val1);
    theRecordWriter.write(key1, nullWritable);
    theRecordWriter.write(key2, null);
    theRecordWriter.write(null, null);
    theRecordWriter.write(key1, val1);
  } finally {
    theRecordWriter.close(tContext);
  }

  OutputFormat outputFormat = ReflectionUtils.newInstance(
      tContext.getOutputFormatClass(), conf);
  OutputCommitter committer = outputFormat.getOutputCommitter(tContext);
  committer.commitTask(tContext);
}

private void writeOutput(TaskAttempt attempt, Configuration conf)
  throws Exception {
  TaskAttemptContext tContext = new TaskAttemptContextImpl(conf, 
      TypeConverter.fromYarn(attempt.getID()));

  TextOutputFormat<?, ?> theOutputFormat = new TextOutputFormat();
  RecordWriter theRecordWriter = theOutputFormat
      .getRecordWriter(tContext);

  NullWritable nullWritable = NullWritable.get();
  try {
    theRecordWriter.write(key1, val1);
    theRecordWriter.write(null, nullWritable);
    theRecordWriter.write(null, val1);
    theRecordWriter.write(nullWritable, val2);
    theRecordWriter.write(key2, nullWritable);
    theRecordWriter.write(key1, null);
    theRecordWriter.write(null, null);
    theRecordWriter.write(key2, val2);
  } finally {
    theRecordWriter.close(tContext);
  }

  OutputFormat outputFormat = ReflectionUtils.newInstance(
      tContext.getOutputFormatClass(), conf);
  OutputCommitter committer = outputFormat.getOutputCommitter(tContext);
  committer.commitTask(tContext);
}

public void verifyHsTaskAttempts(JSONObject json, Task task)
    throws JSONException {
  assertEquals("incorrect number of elements", 1, json.length());
  JSONObject attempts = json.getJSONObject("taskAttempts");
  assertEquals("incorrect number of elements", 1, json.length());
  JSONArray arr = attempts.getJSONArray("taskAttempt");
  for (TaskAttempt att : task.getAttempts().values()) {
    TaskAttemptId id = att.getID();
    String attid = MRApps.toString(id);
    Boolean found = false;

    for (int i = 0; i < arr.length(); i++) {
      JSONObject info = arr.getJSONObject(i);
      if (attid.matches(info.getString("id"))) {
        found = true;
        verifyHsTaskAttempt(info, att, task.getType());
      }
    }
    assertTrue("task attempt with id: " + attid
        + " not in web service output", found);
  }
}

public void verifyHsJobTaskAttemptCounters(JSONObject info, TaskAttempt att)
    throws JSONException {

  assertEquals("incorrect number of elements", 2, info.length());

  WebServicesTestUtils.checkStringMatch("id", MRApps.toString(att.getID()),
      info.getString("id"));

  // just do simple verification of fields - not data is correct
  // in the fields
  JSONArray counterGroups = info.getJSONArray("taskAttemptCounterGroup");
  for (int i = 0; i < counterGroups.length(); i++) {
    JSONObject counterGroup = counterGroups.getJSONObject(i);
    String name = counterGroup.getString("counterGroupName");
    assertTrue("name not set", (name != null && !name.isEmpty()));
    JSONArray counters = counterGroup.getJSONArray("counter");
    for (int j = 0; j < counters.length(); j++) {
      JSONObject counter = counters.getJSONObject(j);
      String counterName = counter.getString("name");
      assertTrue("name not set",
          (counterName != null && !counterName.isEmpty()));
      long value = counter.getLong("value");
      assertTrue("value  >= 0", value >= 0);
    }
  }
}

public void verifyAMTaskAttemptXML(Element element, TaskAttempt att,
    TaskType ttype) {
  verifyTaskAttemptGeneric(att, ttype,
      WebServicesTestUtils.getXmlString(element, "id"),
      WebServicesTestUtils.getXmlString(element, "state"),
      WebServicesTestUtils.getXmlString(element, "type"),
      WebServicesTestUtils.getXmlString(element, "rack"),
      WebServicesTestUtils.getXmlString(element, "nodeHttpAddress"),
      WebServicesTestUtils.getXmlString(element, "diagnostics"),
      WebServicesTestUtils.getXmlString(element, "assignedContainerId"),
      WebServicesTestUtils.getXmlLong(element, "startTime"),
      WebServicesTestUtils.getXmlLong(element, "finishTime"),
      WebServicesTestUtils.getXmlLong(element, "elapsedTime"),
      WebServicesTestUtils.getXmlFloat(element, "progress"));

  if (ttype == TaskType.REDUCE) {
    verifyReduceTaskAttemptGeneric(att,
        WebServicesTestUtils.getXmlLong(element, "shuffleFinishTime"),
        WebServicesTestUtils.getXmlLong(element, "mergeFinishTime"),
        WebServicesTestUtils.getXmlLong(element, "elapsedShuffleTime"),
        WebServicesTestUtils.getXmlLong(element, "elapsedMergeTime"),
        WebServicesTestUtils.getXmlLong(element, "elapsedReduceTime"));
  }
}

public void verifyAMTaskAttempt(JSONObject info, TaskAttempt att,
    TaskType ttype) throws JSONException {
  if (ttype == TaskType.REDUCE) {
    assertEquals("incorrect number of elements", 17, info.length());
  } else {
    assertEquals("incorrect number of elements", 12, info.length());
  }

  verifyTaskAttemptGeneric(att, ttype, info.getString("id"),
      info.getString("state"), info.getString("type"),
      info.getString("rack"), info.getString("nodeHttpAddress"),
      info.getString("diagnostics"), info.getString("assignedContainerId"),
      info.getLong("startTime"), info.getLong("finishTime"),
      info.getLong("elapsedTime"), (float) info.getDouble("progress"));

  if (ttype == TaskType.REDUCE) {
    verifyReduceTaskAttemptGeneric(att, info.getLong("shuffleFinishTime"),
        info.getLong("mergeFinishTime"), info.getLong("elapsedShuffleTime"),
        info.getLong("elapsedMergeTime"), info.getLong("elapsedReduceTime"));
  }
}

public void verifyAMTaskAttempts(JSONObject json, Task task)
    throws JSONException {
  assertEquals("incorrect number of elements", 1, json.length());
  JSONObject attempts = json.getJSONObject("taskAttempts");
  assertEquals("incorrect number of elements", 1, json.length());
  JSONArray arr = attempts.getJSONArray("taskAttempt");
  for (TaskAttempt att : task.getAttempts().values()) {
    TaskAttemptId id = att.getID();
    String attid = MRApps.toString(id);
    Boolean found = false;

    for (int i = 0; i < arr.length(); i++) {
      JSONObject info = arr.getJSONObject(i);
      if (attid.matches(info.getString("id"))) {
        found = true;
        verifyAMTaskAttempt(info, att, task.getType());
      }
    }
    assertTrue("task attempt with id: " + attid
        + " not in web service output", found);
  }
}

public void verifyAMTaskAttemptsXML(NodeList nodes, Task task) {
  assertEquals("incorrect number of elements", 1, nodes.getLength());

  for (TaskAttempt att : task.getAttempts().values()) {
    TaskAttemptId id = att.getID();
    String attid = MRApps.toString(id);
    Boolean found = false;
    for (int i = 0; i < nodes.getLength(); i++) {
      Element element = (Element) nodes.item(i);

      if (attid.matches(WebServicesTestUtils.getXmlString(element, "id"))) {
        found = true;
        verifyAMTaskAttemptXML(element, att, task.getType());
      }
    }
    assertTrue("task with id: " + attid + " not in web service output", found);
  }
}

public void verifyAMJobTaskAttemptCounters(JSONObject info, TaskAttempt att)
    throws JSONException {

  assertEquals("incorrect number of elements", 2, info.length());

  WebServicesTestUtils.checkStringMatch("id", MRApps.toString(att.getID()),
      info.getString("id"));

  // just do simple verification of fields - not data is correct
  // in the fields
  JSONArray counterGroups = info.getJSONArray("taskAttemptCounterGroup");
  for (int i = 0; i < counterGroups.length(); i++) {
    JSONObject counterGroup = counterGroups.getJSONObject(i);
    String name = counterGroup.getString("counterGroupName");
    assertTrue("name not set", (name != null && !name.isEmpty()));
    JSONArray counters = counterGroup.getJSONArray("counter");
    for (int j = 0; j < counters.length(); j++) {
      JSONObject counter = counters.getJSONObject(j);
      String counterName = counter.getString("name");
      assertTrue("name not set",
          (counterName != null && !counterName.isEmpty()));
      long value = counter.getLong("value");
      assertTrue("value  >= 0", value >= 0);
    }
  }
}

private void testMRAppHistory(MRApp app) throws Exception {
  Configuration conf = new Configuration();
  Job job = app.submit(conf);
  app.waitForState(job, JobState.FAILED);
  Map<TaskId, Task> tasks = job.getTasks();

  Assert.assertEquals("Num tasks is not correct", 1, tasks.size());
  Task task = tasks.values().iterator().next();
  Assert.assertEquals("Task state not correct", TaskState.FAILED, task
      .getReport().getTaskState());
  Map<TaskAttemptId, TaskAttempt> attempts = tasks.values().iterator().next()
      .getAttempts();
  Assert.assertEquals("Num attempts is not correct", 4, attempts.size());

  Iterator<TaskAttempt> it = attempts.values().iterator();
  TaskAttemptReport report = it.next().getReport();
  Assert.assertEquals("Attempt state not correct", TaskAttemptState.FAILED,
      report.getTaskAttemptState());
  Assert.assertEquals("Diagnostic Information is not Correct",
      "Test Diagnostic Event", report.getDiagnosticInfo());
  report = it.next().getReport();
  Assert.assertEquals("Attempt state not correct", TaskAttemptState.FAILED,
      report.getTaskAttemptState());
}

public void waitForState(TaskAttempt attempt, 
    TaskAttemptState finalState) throws Exception {
  int timeoutSecs = 0;
  TaskAttemptReport report = attempt.getReport();
  while (!finalState.equals(report.getTaskAttemptState()) &&
      timeoutSecs++ < 20) {
    System.out.println("TaskAttempt State is : " + report.getTaskAttemptState() +
        " Waiting for state : " + finalState +
        "   progress : " + report.getProgress());
    report = attempt.getReport();
    Thread.sleep(500);
  }
  System.out.println("TaskAttempt State is : " + report.getTaskAttemptState());
  Assert.assertEquals("TaskAttempt state is not correct (timedout)",
      finalState, 
      report.getTaskAttemptState());
}

public void verifyCompleted() {
  for (Job job : getContext().getAllJobs().values()) {
    JobReport jobReport = job.getReport();
    System.out.println("Job start time :" + jobReport.getStartTime());
    System.out.println("Job finish time :" + jobReport.getFinishTime());
    Assert.assertTrue("Job start time is not less than finish time",
        jobReport.getStartTime() <= jobReport.getFinishTime());
    Assert.assertTrue("Job finish time is in future",
        jobReport.getFinishTime() <= System.currentTimeMillis());
    for (Task task : job.getTasks().values()) {
      TaskReport taskReport = task.getReport();
      System.out.println("Task start time : " + taskReport.getStartTime());
      System.out.println("Task finish time : " + taskReport.getFinishTime());
      Assert.assertTrue("Task start time is not less than finish time",
          taskReport.getStartTime() <= taskReport.getFinishTime());
      for (TaskAttempt attempt : task.getAttempts().values()) {
        TaskAttemptReport attemptReport = attempt.getReport();
        Assert.assertTrue("Attempt start time is not less than finish time",
            attemptReport.getStartTime() <= attemptReport.getFinishTime());
      }
    }
  }
}

public void verifyHsTaskAttemptsXML(NodeList nodes, Task task) {
  assertEquals("incorrect number of elements", 1, nodes.getLength());

  for (TaskAttempt att : task.getAttempts().values()) {
    TaskAttemptId id = att.getID();
    String attid = MRApps.toString(id);
    Boolean found = false;
    for (int i = 0; i < nodes.getLength(); i++) {
      Element element = (Element) nodes.item(i);

      if (attid.matches(WebServicesTestUtils.getXmlString(element, "id"))) {
        found = true;
        verifyHsTaskAttemptXML(element, att, task.getType());
      }
    }
    assertTrue("task with id: " + attid + " not in web service output", found);
  }
}

@Test
//All Task attempts are timed out, leading to Job failure
public void testTimedOutTask() throws Exception {
  MRApp app = new TimeOutTaskMRApp(1, 0);
  Configuration conf = new Configuration();
  int maxAttempts = 2;
  conf.setInt(MRJobConfig.MAP_MAX_ATTEMPTS, maxAttempts);
  // disable uberization (requires entire job to be reattempted, so max for
  // subtask attempts is overridden to 1)
  conf.setBoolean(MRJobConfig.JOB_UBERTASK_ENABLE, false);
  Job job = app.submit(conf);
  app.waitForState(job, JobState.FAILED);
  Map<TaskId,Task> tasks = job.getTasks();
  Assert.assertEquals("Num tasks is not correct", 1, tasks.size());
  Task task = tasks.values().iterator().next();
  Assert.assertEquals("Task state not correct", TaskState.FAILED,
      task.getReport().getTaskState());
  Map<TaskAttemptId, TaskAttempt> attempts =
      tasks.values().iterator().next().getAttempts();
  Assert.assertEquals("Num attempts is not correct", maxAttempts,
      attempts.size());
  for (TaskAttempt attempt : attempts.values()) {
    Assert.assertEquals("Attempt state not correct", TaskAttemptState.FAILED,
        attempt.getReport().getTaskAttemptState());
  }
}

private void updateStatus(MRApp app, TaskAttempt attempt, Phase phase) {
  TaskAttemptStatusUpdateEvent.TaskAttemptStatus status = new TaskAttemptStatusUpdateEvent.TaskAttemptStatus();
  status.counters = new Counters();
  status.fetchFailedMaps = new ArrayList<TaskAttemptId>();
  status.id = attempt.getID();
  status.mapFinishTime = 0;
  status.phase = phase;
  status.progress = 0.5f;
  status.shuffleFinishTime = 0;
  status.sortFinishTime = 0;
  status.stateString = "OK";
  status.taskState = attempt.getState();
  TaskAttemptStatusUpdateEvent event = new TaskAttemptStatusUpdateEvent(attempt.getID(),
      status);
  app.getContext().getEventHandler().handle(event);
}

@Override
protected Collection<TaskAttempt> getTaskAttempts() {
  List<TaskAttempt> fewTaskAttemps = new ArrayList<TaskAttempt>();
  String taskTypeStr = $(TASK_TYPE);
  TaskType taskType = MRApps.taskType(taskTypeStr);
  String attemptStateStr = $(ATTEMPT_STATE);
  TaskAttemptStateUI neededState = MRApps
      .taskAttemptState(attemptStateStr);
  Job j = app.getJob();
  Map<TaskId, Task> tasks = j.getTasks(taskType);
  for (Task task : tasks.values()) {
    Map<TaskAttemptId, TaskAttempt> attempts = task.getAttempts();
    for (TaskAttempt attempt : attempts.values()) {
      if (neededState.correspondsTo(attempt.getState())) {
        fewTaskAttemps.add(attempt);
      }
    }
  }
  return fewTaskAttemps;
}

@GET
@Path("/mapreduce/jobs/{jobid}/tasks/{taskid}/attempts")
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
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);
  checkAccess(job, hsr);
  Task task = AMWebServices.getTaskFromTaskIdString(tid, job);
  for (TaskAttempt ta : task.getAttempts().values()) {
    if (ta != null) {
      if (task.getType() == TaskType.REDUCE) {
        attempts.add(new ReduceTaskAttemptInfo(ta, task.getType()));
      } else {
        attempts.add(new TaskAttemptInfo(ta, task.getType(), false));
      }
    }
  }
  return attempts;
}

@GET
@Path("/mapreduce/jobs/{jobid}/tasks/{taskid}/attempts/{attemptid}")
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
public TaskAttemptInfo getJobTaskAttemptId(@Context HttpServletRequest hsr,
    @PathParam("jobid") String jid, @PathParam("taskid") String tid,
    @PathParam("attemptid") String attId) {

  init();
  Job job = AMWebServices.getJobFromJobIdString(jid, ctx);
  checkAccess(job, hsr);
  Task task = AMWebServices.getTaskFromTaskIdString(tid, job);
  TaskAttempt ta = AMWebServices.getTaskAttemptFromTaskAttemptString(attId,
      task);
  if (task.getType() == TaskType.REDUCE) {
    return new ReduceTaskAttemptInfo(ta, task.getType());
  } else {
    return new TaskAttemptInfo(ta, task.getType(), false);
  }
}

private void constructTaskReport() {
  loadAllTaskAttempts();
  this.report = Records.newRecord(TaskReport.class);
  report.setTaskId(taskId);
  long minLaunchTime = Long.MAX_VALUE;
  for(TaskAttempt attempt: attempts.values()) {
    minLaunchTime = Math.min(minLaunchTime, attempt.getLaunchTime());
  }
  minLaunchTime = minLaunchTime == Long.MAX_VALUE ? -1 : minLaunchTime;
  report.setStartTime(minLaunchTime);
  report.setFinishTime(taskInfo.getFinishTime());
  report.setTaskState(getState());
  report.setProgress(getProgress());
  Counters counters = getCounters();
  if (counters == null) {
    counters = EMPTY_COUNTERS;
  }
  report.setCounters(TypeConverter.toYarn(counters));
  if (successfulAttempt != null) {
    report.setSuccessfulAttempt(successfulAttempt);
  }
  report.addAllDiagnostics(reportDiagnostics);
  report
      .addAllRunningAttempts(new ArrayList<TaskAttemptId>(attempts.keySet()));
}

public void verifyHsTaskAttemptXML(Element element, TaskAttempt att,
    TaskType ttype) {
  verifyTaskAttemptGeneric(att, ttype,
      WebServicesTestUtils.getXmlString(element, "id"),
      WebServicesTestUtils.getXmlString(element, "state"),
      WebServicesTestUtils.getXmlString(element, "type"),
      WebServicesTestUtils.getXmlString(element, "rack"),
      WebServicesTestUtils.getXmlString(element, "nodeHttpAddress"),
      WebServicesTestUtils.getXmlString(element, "diagnostics"),
      WebServicesTestUtils.getXmlString(element, "assignedContainerId"),
      WebServicesTestUtils.getXmlLong(element, "startTime"),
      WebServicesTestUtils.getXmlLong(element, "finishTime"),
      WebServicesTestUtils.getXmlLong(element, "elapsedTime"),
      WebServicesTestUtils.getXmlFloat(element, "progress"));

  if (ttype == TaskType.REDUCE) {
    verifyReduceTaskAttemptGeneric(att,
        WebServicesTestUtils.getXmlLong(element, "shuffleFinishTime"),
        WebServicesTestUtils.getXmlLong(element, "mergeFinishTime"),
        WebServicesTestUtils.getXmlLong(element, "elapsedShuffleTime"),
        WebServicesTestUtils.getXmlLong(element, "elapsedMergeTime"),
        WebServicesTestUtils.getXmlLong(element, "elapsedReduceTime"));
  }
}

private TaskAttempt getSuccessfulAttempt(Task task) {
  for (TaskAttempt attempt : task.getAttempts().values()) {
    if (attempt.getState() == TaskAttemptState.SUCCEEDED) {
      return attempt;
    }
  }
  return null;
}

@GET
@Path("/jobs/{jobid}/tasks/{taskid}/attempts/{attemptid}/counters")
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
public JobTaskAttemptCounterInfo getJobTaskAttemptIdCounters(
    @Context HttpServletRequest hsr, @PathParam("jobid") String jid,
    @PathParam("taskid") String tid, @PathParam("attemptid") String attId) {

  init();
  Job job = getJobFromJobIdString(jid, appCtx);
  checkAccess(job, hsr);
  Task task = getTaskFromTaskIdString(tid, job);
  TaskAttempt ta = getTaskAttemptFromTaskAttemptString(attId, task);
  return new JobTaskAttemptCounterInfo(ta);
}

@Override
public void transition(JobImpl job, JobEvent event) {
  //get number of shuffling reduces
  int shufflingReduceTasks = 0;
  for (TaskId taskId : job.reduceTasks) {
    Task task = job.tasks.get(taskId);
    if (TaskState.RUNNING.equals(task.getState())) {
      for(TaskAttempt attempt : task.getAttempts().values()) {
        if(attempt.getPhase() == Phase.SHUFFLE) {
          shufflingReduceTasks++;
          break;
        }
      }
    }
  }

  JobTaskAttemptFetchFailureEvent fetchfailureEvent = 
    (JobTaskAttemptFetchFailureEvent) event;
  for (org.apache.hadoop.mapreduce.v2.api.records.TaskAttemptId mapId : 
        fetchfailureEvent.getMaps()) {
    Integer fetchFailures = job.fetchFailuresMapping.get(mapId);
    fetchFailures = (fetchFailures == null) ? 1 : (fetchFailures+1);
    job.fetchFailuresMapping.put(mapId, fetchFailures);

    float failureRate = shufflingReduceTasks == 0 ? 1.0f : 
      (float) fetchFailures / shufflingReduceTasks;
    // declare faulty if fetch-failures >= max-allowed-failures
    if (fetchFailures >= job.getMaxFetchFailuresNotifications()
        && failureRate >= job.getMaxAllowedFetchFailuresFraction()) {
      LOG.info("Too many fetch-failures for output of task attempt: " + 
          mapId + " ... raising fetch failure to map");
      job.eventHandler.handle(new TaskAttemptEvent(mapId, 
          TaskAttemptEventType.TA_TOO_MANY_FETCH_FAILURE));
      job.fetchFailuresMapping.remove(mapId);
    }
  }
}

@Override
public TaskAttempt getAttempt(TaskAttemptId attemptID) {
  readLock.lock();
  try {
    return attempts.get(attemptID);
  } finally {
    readLock.unlock();
  }
}

@Override
public float getProgress() {
  readLock.lock();
  try {
    TaskAttempt bestAttempt = selectBestAttempt();
    if (bestAttempt == null) {
      return 0f;
    }
    return bestAttempt.getProgress();
  } finally {
    readLock.unlock();
  }
}

@Test
public void testTaskAttemptIdCounters() throws JSONException, Exception {
  WebResource r = resource();
  Map<JobId, Job> jobsMap = appContext.getAllJobs();

  for (JobId id : jobsMap.keySet()) {
    String jobId = MRApps.toString(id);

    for (Task task : jobsMap.get(id).getTasks().values()) {
      String tid = MRApps.toString(task.getID());

      for (TaskAttempt att : task.getAttempts().values()) {
        TaskAttemptId attemptid = att.getID();
        String attid = MRApps.toString(attemptid);

        ClientResponse response = r.path("ws").path("v1").path("history")
            .path("mapreduce").path("jobs").path(jobId).path("tasks")
            .path(tid).path("attempts").path(attid).path("counters")
            .accept(MediaType.APPLICATION_JSON).get(ClientResponse.class);
        assertEquals(MediaType.APPLICATION_JSON_TYPE, response.getType());
        JSONObject json = response.getEntity(JSONObject.class);
        assertEquals("incorrect number of elements", 1, json.length());
        JSONObject info = json.getJSONObject("jobTaskAttemptCounters");
        verifyHsJobTaskAttemptCounters(info, att);
      }
    }
  }
}

private long getFinishTime() {
  if (!isFinished()) {
    return 0;
  }
  long finishTime = 0;
  for (TaskAttempt at : attempts.values()) {
    //select the max finish time of all attempts
    if (finishTime < at.getFinishTime()) {
      finishTime = at.getFinishTime();
    }
  }
  return finishTime;
}

private long getFinishTime(TaskAttemptId taId) {
  if (taId == null) {
    return clock.getTime();
  }
  long finishTime = 0;
  for (TaskAttempt at : attempts.values()) {
    //select the max finish time of all attempts
    if (at.getID().equals(taId)) {
      return at.getFinishTime();
    }
  }
  return finishTime;
}

private TaskAttempt selectBestAttempt() {
  if (successfulAttempt != null) {
    return attempts.get(successfulAttempt);
  }

  float progress = 0f;
  TaskAttempt result = null;
  for (TaskAttempt at : attempts.values()) {
    switch (at.getState()) {

    // ignore all failed task attempts
    case FAILED: 
    case KILLED:
      continue;      
    }      
    if (result == null) {
      result = at; //The first time around
    }
    // calculate the best progress
    float attemptProgress = at.getProgress();
    if (attemptProgress > progress) {
      result = at;
      progress = attemptProgress;
    }
  }
  return result;
}

protected TaskAttempt getSuccessfulAttempt() {
  readLock.lock();
  try {
    if (null == successfulAttempt) {
      return null;
    }
    return attempts.get(successfulAttempt);
  } finally {
    readLock.unlock();
  }
}