/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.mapreduce.v2.app.job.impl;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.EnumSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapreduce.Counters;
import org.apache.hadoop.mapreduce.OutputCommitter;
import org.apache.hadoop.mapreduce.TaskAttemptID;
import org.apache.hadoop.mapreduce.TypeConverter;
import org.apache.hadoop.mapreduce.jobhistory.JobHistoryEvent;
import org.apache.hadoop.mapreduce.jobhistory.JobHistoryParser.TaskAttemptInfo;
import org.apache.hadoop.mapreduce.jobhistory.JobHistoryParser.TaskInfo;
import org.apache.hadoop.mapreduce.jobhistory.TaskFailedEvent;
import org.apache.hadoop.mapreduce.jobhistory.TaskFinishedEvent;
import org.apache.hadoop.mapreduce.jobhistory.TaskStartedEvent;
import org.apache.hadoop.mapreduce.security.token.JobTokenIdentifier;
import org.apache.hadoop.mapreduce.v2.api.records.JobId;
import org.apache.hadoop.mapreduce.v2.api.records.TaskAttemptCompletionEvent;
import org.apache.hadoop.mapreduce.v2.api.records.TaskAttemptCompletionEventStatus;
import org.apache.hadoop.mapreduce.v2.api.records.TaskAttemptId;
import org.apache.hadoop.mapreduce.v2.api.records.TaskAttemptState;
import org.apache.hadoop.mapreduce.v2.api.records.TaskId;
import org.apache.hadoop.mapreduce.v2.api.records.TaskReport;
import org.apache.hadoop.mapreduce.v2.api.records.TaskState;
import org.apache.hadoop.mapreduce.v2.api.records.TaskType;
import org.apache.hadoop.mapreduce.v2.app.AppContext;
import org.apache.hadoop.mapreduce.v2.app.TaskAttemptListener;
import org.apache.hadoop.mapreduce.v2.app.job.Task;
import org.apache.hadoop.mapreduce.v2.app.job.TaskAttempt;
import org.apache.hadoop.mapreduce.v2.app.job.event.JobDiagnosticsUpdateEvent;
import org.apache.hadoop.mapreduce.v2.app.job.event.JobEvent;
import org.apache.hadoop.mapreduce.v2.app.job.event.JobEventType;
import org.apache.hadoop.mapreduce.v2.app.job.event.JobMapTaskRescheduledEvent;
import org.apache.hadoop.mapreduce.v2.app.job.event.JobTaskAttemptCompletedEvent;
import org.apache.hadoop.mapreduce.v2.app.job.event.JobTaskEvent;
import org.apache.hadoop.mapreduce.v2.app.job.event.TaskAttemptEvent;
import org.apache.hadoop.mapreduce.v2.app.job.event.TaskAttemptEventType;
import org.apache.hadoop.mapreduce.v2.app.job.event.TaskEvent;
import org.apache.hadoop.mapreduce.v2.app.job.event.TaskEventType;
import org.apache.hadoop.mapreduce.v2.app.job.event.TaskTAttemptEvent;
import org.apache.hadoop.mapreduce.v2.app.metrics.MRAppMetrics;
import org.apache.hadoop.mapreduce.v2.app.rm.ContainerFailedEvent;
import org.apache.hadoop.mapreduce.v2.util.MRBuilderUtils;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.yarn.Clock;
import org.apache.hadoop.yarn.event.EventHandler;
import org.apache.hadoop.yarn.factories.RecordFactory;
import org.apache.hadoop.yarn.factory.providers.RecordFactoryProvider;
import org.apache.hadoop.yarn.state.InvalidStateTransitonException;
import org.apache.hadoop.yarn.state.MultipleArcTransition;
import org.apache.hadoop.yarn.state.SingleArcTransition;
import org.apache.hadoop.yarn.state.StateMachine;
import org.apache.hadoop.yarn.state.StateMachineFactory;
/**
* Implementation of Task interface.
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public abstract class TaskImpl implements Task, EventHandler<TaskEvent> {
private static final Log LOG = LogFactory.getLog(TaskImpl.class);
protected final JobConf conf;
protected final Path jobFile;
protected final OutputCommitter committer;
protected final int partition;
protected final TaskAttemptListener taskAttemptListener;
protected final EventHandler eventHandler;
private final TaskId taskId;
private Map<TaskAttemptId, TaskAttempt> attempts;
private final int maxAttempts;
protected final Clock clock;
private final Lock readLock;
private final Lock writeLock;
private final MRAppMetrics metrics;
protected final AppContext appContext;
private long scheduledTime;
private final RecordFactory recordFactory = RecordFactoryProvider.getRecordFactory(null);
protected Credentials credentials;
protected Token<JobTokenIdentifier> jobToken;
// counts the number of attempts that are either running or in a state where
// they will come to be running when they get a Container
private int numberUncompletedAttempts = 0;
private boolean historyTaskStartGenerated = false;
private static final SingleArcTransition<TaskImpl, TaskEvent>
ATTEMPT_KILLED_TRANSITION = new AttemptKilledTransition();
private static final SingleArcTransition<TaskImpl, TaskEvent>
KILL_TRANSITION = new KillTransition();
private static final StateMachineFactory
<TaskImpl, TaskState, TaskEventType, TaskEvent>
stateMachineFactory
= new StateMachineFactory<TaskImpl, TaskState, TaskEventType, TaskEvent>
(TaskState.NEW)
// define the state machine of Task
// Transitions from NEW state
.addTransition(TaskState.NEW, TaskState.SCHEDULED,
TaskEventType.T_SCHEDULE, new InitialScheduleTransition())
.addTransition(TaskState.NEW, TaskState.KILLED,
TaskEventType.T_KILL, new KillNewTransition())
// Transitions from SCHEDULED state
//when the first attempt is launched, the task state is set to RUNNING
.addTransition(TaskState.SCHEDULED, TaskState.RUNNING,
TaskEventType.T_ATTEMPT_LAUNCHED, new LaunchTransition())
.addTransition(TaskState.SCHEDULED, TaskState.KILL_WAIT,
TaskEventType.T_KILL, KILL_TRANSITION)
.addTransition(TaskState.SCHEDULED, TaskState.SCHEDULED,
TaskEventType.T_ATTEMPT_KILLED, ATTEMPT_KILLED_TRANSITION)
.addTransition(TaskState.SCHEDULED,
EnumSet.of(TaskState.SCHEDULED, TaskState.FAILED),
TaskEventType.T_ATTEMPT_FAILED,
new AttemptFailedTransition())
// Transitions from RUNNING state
.addTransition(TaskState.RUNNING, TaskState.RUNNING,
TaskEventType.T_ATTEMPT_LAUNCHED) //more attempts may start later
.addTransition(TaskState.RUNNING, TaskState.RUNNING,
TaskEventType.T_ATTEMPT_COMMIT_PENDING,
new AttemptCommitPendingTransition())
.addTransition(TaskState.RUNNING, TaskState.RUNNING,
TaskEventType.T_ADD_SPEC_ATTEMPT, new RedundantScheduleTransition())
.addTransition(TaskState.RUNNING, TaskState.SUCCEEDED,
TaskEventType.T_ATTEMPT_SUCCEEDED,
new AttemptSucceededTransition())
.addTransition(TaskState.RUNNING, TaskState.RUNNING,
TaskEventType.T_ATTEMPT_KILLED,
ATTEMPT_KILLED_TRANSITION)
.addTransition(TaskState.RUNNING,
EnumSet.of(TaskState.RUNNING, TaskState.FAILED),
TaskEventType.T_ATTEMPT_FAILED,
new AttemptFailedTransition())
.addTransition(TaskState.RUNNING, TaskState.KILL_WAIT,
TaskEventType.T_KILL, KILL_TRANSITION)
// Transitions from KILL_WAIT state
.addTransition(TaskState.KILL_WAIT,
EnumSet.of(TaskState.KILL_WAIT, TaskState.KILLED),
TaskEventType.T_ATTEMPT_KILLED,
new KillWaitAttemptKilledTransition())
// Ignore-able transitions.
.addTransition(
TaskState.KILL_WAIT,
TaskState.KILL_WAIT,
EnumSet.of(TaskEventType.T_KILL,
TaskEventType.T_ATTEMPT_LAUNCHED,
TaskEventType.T_ATTEMPT_COMMIT_PENDING,
TaskEventType.T_ATTEMPT_FAILED,
TaskEventType.T_ATTEMPT_SUCCEEDED,
TaskEventType.T_ADD_SPEC_ATTEMPT))
// Transitions from SUCCEEDED state
.addTransition(TaskState.SUCCEEDED, //only possible for map tasks
EnumSet.of(TaskState.SCHEDULED, TaskState.FAILED),
TaskEventType.T_ATTEMPT_FAILED, new MapRetroactiveFailureTransition())
// Ignore-able transitions.
.addTransition(
TaskState.SUCCEEDED, TaskState.SUCCEEDED,
EnumSet.of(TaskEventType.T_KILL,
TaskEventType.T_ADD_SPEC_ATTEMPT,
TaskEventType.T_ATTEMPT_LAUNCHED,
TaskEventType.T_ATTEMPT_KILLED))
// Transitions from FAILED state
.addTransition(TaskState.FAILED, TaskState.FAILED,
EnumSet.of(TaskEventType.T_KILL,
TaskEventType.T_ADD_SPEC_ATTEMPT))
// Transitions from KILLED state
.addTransition(TaskState.KILLED, TaskState.KILLED,
EnumSet.of(TaskEventType.T_KILL,
TaskEventType.T_ADD_SPEC_ATTEMPT))
// create the topology tables
.installTopology();
private final StateMachine<TaskState, TaskEventType, TaskEvent>
stateMachine;
// By default, the next TaskAttempt number is zero. Changes during recovery
protected int nextAttemptNumber = 0;
private List<TaskAttemptInfo> taskAttemptsFromPreviousGeneration =
new ArrayList<TaskAttemptInfo>();
private static final class RecoverdAttemptsComparator implements
Comparator<TaskAttemptInfo> {
@Override
public int compare(TaskAttemptInfo attempt1, TaskAttemptInfo attempt2) {
long diff = attempt1.getStartTime() - attempt2.getStartTime();
return diff == 0 ? 0 : (diff < 0 ? -1 : 1);
}
}
private static final RecoverdAttemptsComparator RECOVERED_ATTEMPTS_COMPARATOR =
new RecoverdAttemptsComparator();
//should be set to one which comes first
//saying COMMIT_PENDING
private TaskAttemptId commitAttempt;
private TaskAttemptId successfulAttempt;
private int failedAttempts;
private int finishedAttempts;//finish are total of success, failed and killed
@Override
public TaskState getState() {
return stateMachine.getCurrentState();
}
public TaskImpl(JobId jobId, TaskType taskType, int partition,
EventHandler eventHandler, Path remoteJobConfFile, JobConf conf,
TaskAttemptListener taskAttemptListener, OutputCommitter committer,
Token<JobTokenIdentifier> jobToken,
Credentials credentials, Clock clock,
Map<TaskId, TaskInfo> completedTasksFromPreviousRun, int startCount,
MRAppMetrics metrics, AppContext appContext) {
this.conf = conf;
this.clock = clock;
this.jobFile = remoteJobConfFile;
ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
readLock = readWriteLock.readLock();
writeLock = readWriteLock.writeLock();
this.attempts = Collections.emptyMap();
// This overridable method call is okay in a constructor because we
// have a convention that none of the overrides depends on any
// fields that need initialization.
maxAttempts = getMaxAttempts();
taskId = MRBuilderUtils.newTaskId(jobId, partition, taskType);
this.partition = partition;
this.taskAttemptListener = taskAttemptListener;
this.eventHandler = eventHandler;
this.committer = committer;
this.credentials = credentials;
this.jobToken = jobToken;
this.metrics = metrics;
this.appContext = appContext;
// See if this is from a previous generation.
if (completedTasksFromPreviousRun != null
&& completedTasksFromPreviousRun.containsKey(taskId)) {
// This task has TaskAttempts from previous generation. We have to replay
// them.
LOG.info("Task is from previous run " + taskId);
TaskInfo taskInfo = completedTasksFromPreviousRun.get(taskId);
Map<TaskAttemptID, TaskAttemptInfo> allAttempts =
taskInfo.getAllTaskAttempts();
taskAttemptsFromPreviousGeneration = new ArrayList<TaskAttemptInfo>();
taskAttemptsFromPreviousGeneration.addAll(allAttempts.values());
Collections.sort(taskAttemptsFromPreviousGeneration,
RECOVERED_ATTEMPTS_COMPARATOR);
}
if (taskAttemptsFromPreviousGeneration.isEmpty()) {
// All the previous attempts are exhausted, now start with a new
// generation.
// All the new TaskAttemptIDs are generated based on MR
// ApplicationAttemptID so that attempts from previous lives don't
// over-step the current one. This assumes that a task won't have more
// than 1000 attempts in its single generation, which is very reasonable.
// Someone is nuts if he/she thinks he/she can live with 1000 TaskAttempts
// and requires serious medical attention.
nextAttemptNumber = (startCount - 1) * 1000;
} else {
// There are still some TaskAttempts from previous generation, use them
nextAttemptNumber =
taskAttemptsFromPreviousGeneration.remove(0).getAttemptId().getId();
}
// This "this leak" is okay because the retained pointer is in an
// instance variable.
stateMachine = stateMachineFactory.make(this);
}
@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 TaskAttempt getAttempt(TaskAttemptId attemptID) {
readLock.lock();
try {
return attempts.get(attemptID);
} finally {
readLock.unlock();
}
}
@Override
public TaskId getID() {
return taskId;
}
@Override
public boolean isFinished() {
readLock.lock();
try {
// TODO: Use stateMachine level method?
return (getState() == TaskState.SUCCEEDED ||
getState() == TaskState.FAILED ||
getState() == TaskState.KILLED);
} finally {
readLock.unlock();
}
}
@Override
public TaskReport getReport() {
TaskReport report = recordFactory.newRecordInstance(TaskReport.class);
readLock.lock();
try {
report.setTaskId(taskId);
report.setStartTime(getLaunchTime());
report.setFinishTime(getFinishTime());
report.setTaskState(getState());
report.setProgress(getProgress());
for (TaskAttempt attempt : attempts.values()) {
if (TaskAttemptState.RUNNING.equals(attempt.getState())) {
report.addRunningAttempt(attempt.getID());
}
}
report.setSuccessfulAttempt(successfulAttempt);
for (TaskAttempt att : attempts.values()) {
String prefix = "AttemptID:" + att.getID() + " Info:";
for (CharSequence cs : att.getDiagnostics()) {
report.addDiagnostics(prefix + cs);
}
}
// Add a copy of counters as the last step so that their lifetime on heap
// is as small as possible.
report.setCounters(TypeConverter.toYarn(getCounters()));
return report;
} 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();
}
}
@Override
public float getProgress() {
readLock.lock();
try {
TaskAttempt bestAttempt = selectBestAttempt();
if (bestAttempt == null) {
return 0f;
}
return bestAttempt.getProgress();
} finally {
readLock.unlock();
}
}
//this is always called in read/write lock
private long getLaunchTime() {
long taskLaunchTime = 0;
boolean launchTimeSet = false;
for (TaskAttempt at : attempts.values()) {
// select the least launch time of all attempts
long attemptLaunchTime = at.getLaunchTime();
if (attemptLaunchTime != 0 && !launchTimeSet) {
// For the first non-zero launch time
launchTimeSet = true;
taskLaunchTime = attemptLaunchTime;
} else if (attemptLaunchTime != 0 && taskLaunchTime > attemptLaunchTime) {
taskLaunchTime = attemptLaunchTime;
}
}
if (!launchTimeSet) {
return this.scheduledTime;
}
return taskLaunchTime;
}
//this is always called in read/write lock
//TODO Verify behaviour is Task is killed (no finished attempt)
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 TaskState finished(TaskState finalState) {
if (getState() == TaskState.RUNNING) {
metrics.endRunningTask(this);
}
return finalState;
}
//select the nextAttemptNumber with best progress
// always called inside the Read Lock
private TaskAttempt selectBestAttempt() {
float progress = 0f;
TaskAttempt result = null;
for (TaskAttempt at : attempts.values()) {
switch (at.getState()) {
// ignore all failed task attempts
case FAIL_CONTAINER_CLEANUP:
case FAIL_TASK_CLEANUP:
case FAILED:
case KILL_CONTAINER_CLEANUP:
case KILL_TASK_CLEANUP:
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;
}
@Override
public boolean canCommit(TaskAttemptId taskAttemptID) {
readLock.lock();
boolean canCommit = false;
try {
if (commitAttempt != null) {
canCommit = taskAttemptID.equals(commitAttempt);
LOG.info("Result of canCommit for " + taskAttemptID + ":" + canCommit);
}
} finally {
readLock.unlock();
}
return canCommit;
}
protected abstract TaskAttemptImpl createAttempt();
// No override of this method may require that the subclass be initialized.
protected abstract int getMaxAttempts();
protected TaskAttempt getSuccessfulAttempt() {
readLock.lock();
try {
if (null == successfulAttempt) {
return null;
}
return attempts.get(successfulAttempt);
} finally {
readLock.unlock();
}
}
// This is always called in the Write Lock
private void addAndScheduleAttempt() {
TaskAttempt attempt = createAttempt();
if (LOG.isDebugEnabled()) {
LOG.debug("Created attempt " + attempt.getID());
}
switch (attempts.size()) {
case 0:
attempts = Collections.singletonMap(attempt.getID(), attempt);
break;
case 1:
Map<TaskAttemptId, TaskAttempt> newAttempts
= new LinkedHashMap<TaskAttemptId, TaskAttempt>(maxAttempts);
newAttempts.putAll(attempts);
attempts = newAttempts;
attempts.put(attempt.getID(), attempt);
break;
default:
attempts.put(attempt.getID(), attempt);
break;
}
// Update nextATtemptNumber
if (taskAttemptsFromPreviousGeneration.isEmpty()) {
++nextAttemptNumber;
} else {
// There are still some TaskAttempts from previous generation, use them
nextAttemptNumber =
taskAttemptsFromPreviousGeneration.remove(0).getAttemptId().getId();
}
++numberUncompletedAttempts;
//schedule the nextAttemptNumber
if (failedAttempts > 0) {
eventHandler.handle(new TaskAttemptEvent(attempt.getID(),
TaskAttemptEventType.TA_RESCHEDULE));
} else {
eventHandler.handle(new TaskAttemptEvent(attempt.getID(),
TaskAttemptEventType.TA_SCHEDULE));
}
}
@Override
public void handle(TaskEvent event) {
if (LOG.isDebugEnabled()) {
LOG.debug("Processing " + event.getTaskID() + " of type "
+ event.getType());
}
try {
writeLock.lock();
TaskState oldState = getState();
try {
stateMachine.doTransition(event.getType(), event);
} catch (InvalidStateTransitonException e) {
LOG.error("Can't handle this event at current state for "
+ this.taskId, e);
internalError(event.getType());
}
if (oldState != getState()) {
LOG.info(taskId + " Task Transitioned from " + oldState + " to "
+ getState());
}
} finally {
writeLock.unlock();
}
}
private void internalError(TaskEventType type) {
LOG.error("Invalid event " + type + " on Task " + this.taskId);
eventHandler.handle(new JobDiagnosticsUpdateEvent(
this.taskId.getJobId(), "Invalid event " + type +
" on Task " + this.taskId));
eventHandler.handle(new JobEvent(this.taskId.getJobId(),
JobEventType.INTERNAL_ERROR));
}
// always called inside a transition, in turn inside the Write Lock
private void handleTaskAttemptCompletion(TaskAttemptId attemptId,
TaskAttemptCompletionEventStatus status) {
finishedAttempts++;
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);
tce.setMapOutputServerAddress("http://"
+ 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 static TaskFinishedEvent createTaskFinishedEvent(TaskImpl task, TaskState taskState) {
TaskFinishedEvent tfe =
new TaskFinishedEvent(TypeConverter.fromYarn(task.taskId),
TypeConverter.fromYarn(task.successfulAttempt),
task.getFinishTime(task.successfulAttempt),
TypeConverter.fromYarn(task.taskId.getTaskType()),
taskState.toString(),
task.getCounters());
return tfe;
}
private static TaskFailedEvent createTaskFailedEvent(TaskImpl task, List<String> diag, TaskState taskState, TaskAttemptId taId) {
StringBuilder errorSb = new StringBuilder();
if (diag != null) {
for (String d : diag) {
errorSb.append(", ").append(d);
}
}
TaskFailedEvent taskFailedEvent = new TaskFailedEvent(
TypeConverter.fromYarn(task.taskId),
// Hack since getFinishTime needs isFinished to be true and that doesn't happen till after the transition.
task.getFinishTime(taId),
TypeConverter.fromYarn(task.getType()),
errorSb.toString(),
taskState.toString(),
taId == null ? null : TypeConverter.fromYarn(taId));
return taskFailedEvent;
}
/**
* @return a String representation of the splits.
*
* Subclasses can override this method to provide their own representations
* of splits (if any).
*
*/
protected String getSplitsAsString(){
return "";
}
private static class InitialScheduleTransition
implements SingleArcTransition<TaskImpl, TaskEvent> {
@Override
public void transition(TaskImpl task, TaskEvent event) {
task.addAndScheduleAttempt();
task.scheduledTime = task.clock.getTime();
TaskStartedEvent tse = new TaskStartedEvent(
TypeConverter.fromYarn(task.taskId), task.getLaunchTime(),
TypeConverter.fromYarn(task.taskId.getTaskType()),
task.getSplitsAsString());
task.eventHandler
.handle(new JobHistoryEvent(task.taskId.getJobId(), tse));
task.historyTaskStartGenerated = true;
}
}
// Used when creating a new attempt while one is already running.
// Currently we do this for speculation. In the future we may do this
// for tasks that failed in a way that might indicate application code
// problems, so we can take later failures in parallel and flush the
// job quickly when this happens.
private static class RedundantScheduleTransition
implements SingleArcTransition<TaskImpl, TaskEvent> {
@Override
public void transition(TaskImpl task, TaskEvent event) {
LOG.info("Scheduling a redundant attempt for task " + task.taskId);
task.addAndScheduleAttempt();
}
}
private static class AttemptCommitPendingTransition
implements SingleArcTransition<TaskImpl, TaskEvent> {
@Override
public void transition(TaskImpl task, TaskEvent event) {
TaskTAttemptEvent ev = (TaskTAttemptEvent) event;
// The nextAttemptNumber is commit pending, decide on set the commitAttempt
TaskAttemptId attemptID = ev.getTaskAttemptID();
if (task.commitAttempt == null) {
// TODO: validate attemptID
task.commitAttempt = attemptID;
LOG.info(attemptID + " given a go for committing the task output.");
} else {
// Don't think this can be a pluggable decision, so simply raise an
// event for the TaskAttempt to delete its output.
LOG.info(task.commitAttempt
+ " already given a go for committing the task output, so killing "
+ attemptID);
task.eventHandler.handle(new TaskAttemptEvent(
attemptID, TaskAttemptEventType.TA_KILL));
}
}
}
private static class AttemptSucceededTransition
implements SingleArcTransition<TaskImpl, TaskEvent> {
@Override
public void transition(TaskImpl task, TaskEvent event) {
task.handleTaskAttemptCompletion(
((TaskTAttemptEvent) event).getTaskAttemptID(),
TaskAttemptCompletionEventStatus.SUCCEEDED);
--task.numberUncompletedAttempts;
task.successfulAttempt = ((TaskTAttemptEvent) event).getTaskAttemptID();
task.eventHandler.handle(new JobTaskEvent(
task.taskId, TaskState.SUCCEEDED));
LOG.info("Task succeeded with attempt " + task.successfulAttempt);
// issue kill to all other attempts
if (task.historyTaskStartGenerated) {
TaskFinishedEvent tfe = createTaskFinishedEvent(task,
TaskState.SUCCEEDED);
task.eventHandler.handle(new JobHistoryEvent(task.taskId.getJobId(),
tfe));
}
for (TaskAttempt attempt : task.attempts.values()) {
if (attempt.getID() != task.successfulAttempt &&
// This is okay because it can only talk us out of sending a
// TA_KILL message to an attempt that doesn't need one for
// other reasons.
!attempt.isFinished()) {
LOG.info("Issuing kill to other attempt " + attempt.getID());
task.eventHandler.handle(
new TaskAttemptEvent(attempt.getID(),
TaskAttemptEventType.TA_KILL));
}
}
task.finished(TaskState.SUCCEEDED);
}
}
private static class AttemptKilledTransition implements
SingleArcTransition<TaskImpl, TaskEvent> {
@Override
public void transition(TaskImpl task, TaskEvent event) {
task.handleTaskAttemptCompletion(
((TaskTAttemptEvent) event).getTaskAttemptID(),
TaskAttemptCompletionEventStatus.KILLED);
--task.numberUncompletedAttempts;
if (task.successfulAttempt == null) {
task.addAndScheduleAttempt();
}
}
}
private static class KillWaitAttemptKilledTransition implements
MultipleArcTransition<TaskImpl, TaskEvent, TaskState> {
protected TaskState finalState = TaskState.KILLED;
@Override
public TaskState transition(TaskImpl task, TaskEvent event) {
task.handleTaskAttemptCompletion(
((TaskTAttemptEvent) event).getTaskAttemptID(),
TaskAttemptCompletionEventStatus.KILLED);
// check whether all attempts are finished
if (task.finishedAttempts == task.attempts.size()) {
if (task.historyTaskStartGenerated) {
TaskFailedEvent taskFailedEvent = createTaskFailedEvent(task, null,
finalState, null); // TODO JH verify failedAttempt null
task.eventHandler.handle(new JobHistoryEvent(task.taskId.getJobId(),
taskFailedEvent));
} else {
LOG.debug("Not generating HistoryFinish event since start event not" +
" generated for task: " + task.getID());
}
task.eventHandler.handle(
new JobTaskEvent(task.taskId, finalState));
return finalState;
}
return task.getState();
}
}
private static class AttemptFailedTransition implements
MultipleArcTransition<TaskImpl, TaskEvent, TaskState> {
@Override
public TaskState transition(TaskImpl task, TaskEvent event) {
task.failedAttempts++;
TaskTAttemptEvent castEvent = (TaskTAttemptEvent) event;
if (castEvent.getTaskAttemptID().equals(task.commitAttempt)) {
task.commitAttempt = null;
}
TaskAttempt attempt = task.attempts.get(castEvent.getTaskAttemptID());
if (attempt.getAssignedContainerMgrAddress() != null) {
//container was assigned
task.eventHandler.handle(new ContainerFailedEvent(attempt.getID(),
attempt.getAssignedContainerMgrAddress()));
}
if (task.failedAttempts < task.maxAttempts) {
task.handleTaskAttemptCompletion(
((TaskTAttemptEvent) event).getTaskAttemptID(),
TaskAttemptCompletionEventStatus.FAILED);
// we don't need a new event if we already have a spare
if (--task.numberUncompletedAttempts == 0
&& task.successfulAttempt == null) {
task.addAndScheduleAttempt();
}
} else {
task.handleTaskAttemptCompletion(
((TaskTAttemptEvent) event).getTaskAttemptID(),
TaskAttemptCompletionEventStatus.TIPFAILED);
TaskTAttemptEvent ev = (TaskTAttemptEvent) event;
TaskAttemptId taId = ev.getTaskAttemptID();
if (task.historyTaskStartGenerated) {
TaskFailedEvent taskFailedEvent = createTaskFailedEvent(task, attempt.getDiagnostics(),
TaskState.FAILED, taId);
task.eventHandler.handle(new JobHistoryEvent(task.taskId.getJobId(),
taskFailedEvent));
} else {
LOG.debug("Not generating HistoryFinish event since start event not" +
" generated for task: " + task.getID());
}
task.eventHandler.handle(
new JobTaskEvent(task.taskId, TaskState.FAILED));
return task.finished(TaskState.FAILED);
}
return getDefaultState(task);
}
protected TaskState getDefaultState(Task task) {
return task.getState();
}
protected void unSucceed(TaskImpl task) {
++task.numberUncompletedAttempts;
task.commitAttempt = null;
task.successfulAttempt = null;
}
}
private static class MapRetroactiveFailureTransition
extends AttemptFailedTransition {
@Override
public TaskState transition(TaskImpl task, TaskEvent event) {
//verify that this occurs only for map task
//TODO: consider moving it to MapTaskImpl
if (!TaskType.MAP.equals(task.getType())) {
LOG.error("Unexpected event for REDUCE task " + event.getType());
task.internalError(event.getType());
}
// tell the job about the rescheduling
task.eventHandler.handle(
new JobMapTaskRescheduledEvent(task.taskId));
// super.transition is mostly coded for the case where an
// UNcompleted task failed. When a COMPLETED task retroactively
// fails, we have to let AttemptFailedTransition.transition
// believe that there's no redundancy.
unSucceed(task);
return super.transition(task, event);
}
@Override
protected TaskState getDefaultState(Task task) {
return TaskState.SCHEDULED;
}
}
private static class KillNewTransition
implements SingleArcTransition<TaskImpl, TaskEvent> {
@Override
public void transition(TaskImpl task, TaskEvent event) {
if (task.historyTaskStartGenerated) {
TaskFailedEvent taskFailedEvent = createTaskFailedEvent(task, null,
TaskState.KILLED, null); // TODO Verify failedAttemptId is null
task.eventHandler.handle(new JobHistoryEvent(task.taskId.getJobId(),
taskFailedEvent));
}else {
LOG.debug("Not generating HistoryFinish event since start event not" +
" generated for task: " + task.getID());
}
task.eventHandler.handle(
new JobTaskEvent(task.taskId, TaskState.KILLED));
task.metrics.endWaitingTask(task);
}
}
private void killUnfinishedAttempt(TaskAttempt attempt, String logMsg) {
if (attempt != null && !attempt.isFinished()) {
eventHandler.handle(
new TaskAttemptEvent(attempt.getID(),
TaskAttemptEventType.TA_KILL));
}
}
private static class KillTransition
implements SingleArcTransition<TaskImpl, TaskEvent> {
@Override
public void transition(TaskImpl task, TaskEvent event) {
// issue kill to all non finished attempts
for (TaskAttempt attempt : task.attempts.values()) {
task.killUnfinishedAttempt
(attempt, "Task KILL is received. Killing attempt!");
}
task.numberUncompletedAttempts = 0;
}
}
static class LaunchTransition
implements SingleArcTransition<TaskImpl, TaskEvent> {
@Override
public void transition(TaskImpl task, TaskEvent event) {
task.metrics.launchedTask(task);
task.metrics.runningTask(task);
}
}
}