MAPREDUCE-5533. Fixed MR speculation code to track any TaskAttempts that aren't heart-beating for a while, so that we can aggressively speculate instead of waiting for task-timeout. Contributed by Xuan Gong.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1529229 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Vinod Kumar Vavilapalli 2013-10-04 17:26:56 +00:00
parent 6be30a7799
commit d4324eef14
4 changed files with 320 additions and 7 deletions

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@ -278,6 +278,10 @@ Release 2.1.2 - UNRELEASED
MAPREDUCE-5442. $HADOOP_MAPRED_HOME/$HADOOP_CONF_DIR setting not working on
Windows. (Yingda Chen via cnauroth)
MAPREDUCE-5533. Fixed MR speculation code to track any TaskAttempts that
aren't heart-beating for a while, so that we can aggressively speculate
instead of waiting for task-timeout (Xuan Gong via vinodkv)
Release 2.1.1-beta - 2013-09-23
INCOMPATIBLE CHANGES

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@ -78,6 +78,16 @@ public class DefaultSpeculator extends AbstractService implements
private final Map<Task, AtomicBoolean> pendingSpeculations
= new ConcurrentHashMap<Task, AtomicBoolean>();
// Used to track any TaskAttempts that aren't heart-beating for a while, so
// that we can aggressively speculate instead of waiting for task-timeout.
private final ConcurrentMap<TaskAttemptId, TaskAttemptHistoryStatistics>
runningTaskAttemptStatistics = new ConcurrentHashMap<TaskAttemptId,
TaskAttemptHistoryStatistics>();
// Regular heartbeat from tasks is every 3 secs. So if we don't get a
// heartbeat in 9 secs (3 heartbeats), we simulate a heartbeat with no change
// in progress.
private static final long MAX_WAITTING_TIME_FOR_HEARTBEAT = 9 * 1000;
// These are the current needs, not the initial needs. For each job, these
// record the number of attempts that exist and that are actively
// waiting for a container [as opposed to running or finished]
@ -329,6 +339,9 @@ public class DefaultSpeculator extends AbstractService implements
runningTasks.putIfAbsent(taskID, Boolean.TRUE);
} else {
runningTasks.remove(taskID, Boolean.TRUE);
if (!stateString.equals(TaskAttemptState.STARTING.name())) {
runningTaskAttemptStatistics.remove(attemptID);
}
}
}
@ -389,6 +402,33 @@ public class DefaultSpeculator extends AbstractService implements
long estimatedReplacementEndTime
= now + estimator.estimatedNewAttemptRuntime(taskID);
float progress = taskAttempt.getProgress();
TaskAttemptHistoryStatistics data =
runningTaskAttemptStatistics.get(runningTaskAttemptID);
if (data == null) {
runningTaskAttemptStatistics.put(runningTaskAttemptID,
new TaskAttemptHistoryStatistics(estimatedRunTime, progress, now));
} else {
if (estimatedRunTime == data.getEstimatedRunTime()
&& progress == data.getProgress()) {
// Previous stats are same as same stats
if (data.notHeartbeatedInAWhile(now)) {
// Stats have stagnated for a while, simulate heart-beat.
TaskAttemptStatus taskAttemptStatus = new TaskAttemptStatus();
taskAttemptStatus.id = runningTaskAttemptID;
taskAttemptStatus.progress = progress;
taskAttemptStatus.taskState = taskAttempt.getState();
// Now simulate the heart-beat
handleAttempt(taskAttemptStatus);
}
} else {
// Stats have changed - update our data structure
data.setEstimatedRunTime(estimatedRunTime);
data.setProgress(progress);
data.resetHeartBeatTime(now);
}
}
if (estimatedEndTime < now) {
return PROGRESS_IS_GOOD;
}
@ -511,4 +551,47 @@ public class DefaultSpeculator extends AbstractService implements
// We'll try to issue one map and one reduce speculation per job per run
return maybeScheduleAMapSpeculation() + maybeScheduleAReduceSpeculation();
}
static class TaskAttemptHistoryStatistics {
private long estimatedRunTime;
private float progress;
private long lastHeartBeatTime;
public TaskAttemptHistoryStatistics(long estimatedRunTime, float progress,
long nonProgressStartTime) {
this.estimatedRunTime = estimatedRunTime;
this.progress = progress;
resetHeartBeatTime(nonProgressStartTime);
}
public long getEstimatedRunTime() {
return this.estimatedRunTime;
}
public float getProgress() {
return this.progress;
}
public void setEstimatedRunTime(long estimatedRunTime) {
this.estimatedRunTime = estimatedRunTime;
}
public void setProgress(float progress) {
this.progress = progress;
}
public boolean notHeartbeatedInAWhile(long now) {
if (now - lastHeartBeatTime <= MAX_WAITTING_TIME_FOR_HEARTBEAT) {
return false;
} else {
resetHeartBeatTime(now);
return true;
}
}
public void resetHeartBeatTime(long lastHeartBeatTime) {
this.lastHeartBeatTime = lastHeartBeatTime;
}
}
}

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@ -263,6 +263,13 @@ public class MRApp extends MRAppMaster {
}
public Job submit(Configuration conf) throws Exception {
//TODO: fix the bug where the speculator gets events with
//not-fully-constructed objects. For now, disable speculative exec
return submit(conf, false, false);
}
public Job submit(Configuration conf, boolean mapSpeculative,
boolean reduceSpeculative) throws Exception {
String user = conf.get(MRJobConfig.USER_NAME, UserGroupInformation
.getCurrentUser().getShortUserName());
conf.set(MRJobConfig.USER_NAME, user);
@ -270,9 +277,8 @@ public class MRApp extends MRAppMaster {
conf.setBoolean(MRJobConfig.MR_AM_CREATE_JH_INTERMEDIATE_BASE_DIR, true);
// TODO: fix the bug where the speculator gets events with
// not-fully-constructed objects. For now, disable speculative exec
LOG.info("****DISABLING SPECULATIVE EXECUTION*****");
conf.setBoolean(MRJobConfig.MAP_SPECULATIVE, false);
conf.setBoolean(MRJobConfig.REDUCE_SPECULATIVE, false);
conf.setBoolean(MRJobConfig.MAP_SPECULATIVE, mapSpeculative);
conf.setBoolean(MRJobConfig.REDUCE_SPECULATIVE, reduceSpeculative);
init(conf);
start();

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@ -0,0 +1,220 @@
/**
* 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;
import java.util.Iterator;
import java.util.Map;
import java.util.Random;
import junit.framework.Assert;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.v2.api.records.JobState;
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.TaskState;
import org.apache.hadoop.mapreduce.v2.app.ControlledClock;
import org.apache.hadoop.mapreduce.v2.app.MRApp;
import org.apache.hadoop.mapreduce.v2.app.job.Job;
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.TaskAttemptEvent;
import org.apache.hadoop.mapreduce.v2.app.job.event.TaskAttemptEventType;
import org.apache.hadoop.mapreduce.v2.app.job.event.TaskAttemptStatusUpdateEvent;
import org.apache.hadoop.mapreduce.v2.app.job.event.TaskAttemptStatusUpdateEvent.TaskAttemptStatus;
import org.apache.hadoop.yarn.event.EventHandler;
import org.apache.hadoop.yarn.util.Clock;
import org.apache.hadoop.yarn.util.SystemClock;
import org.junit.Test;
@SuppressWarnings({ "unchecked", "rawtypes" })
public class TestSpeculativeExecutionWithMRApp {
private static final int NUM_MAPPERS = 5;
private static final int NUM_REDUCERS = 0;
@Test(timeout = 60000)
public void testSpeculateSuccessfulWithoutUpdateEvents() throws Exception {
Clock actualClock = new SystemClock();
ControlledClock clock = new ControlledClock(actualClock);
clock.setTime(System.currentTimeMillis());
MRApp app =
new MRApp(NUM_MAPPERS, NUM_REDUCERS, false, "test", true, clock);
Job job = app.submit(new Configuration(), true, true);
app.waitForState(job, JobState.RUNNING);
Map<TaskId, Task> tasks = job.getTasks();
Assert.assertEquals("Num tasks is not correct", NUM_MAPPERS + NUM_REDUCERS,
tasks.size());
Iterator<Task> taskIter = tasks.values().iterator();
while (taskIter.hasNext()) {
app.waitForState(taskIter.next(), TaskState.RUNNING);
}
// Process the update events
clock.setTime(System.currentTimeMillis() + 2000);
EventHandler appEventHandler = app.getContext().getEventHandler();
for (Map.Entry<TaskId, Task> mapTask : tasks.entrySet()) {
for (Map.Entry<TaskAttemptId, TaskAttempt> taskAttempt : mapTask
.getValue().getAttempts().entrySet()) {
TaskAttemptStatus status =
createTaskAttemptStatus(taskAttempt.getKey(), (float) 0.8,
TaskAttemptState.RUNNING);
TaskAttemptStatusUpdateEvent event =
new TaskAttemptStatusUpdateEvent(taskAttempt.getKey(), status);
appEventHandler.handle(event);
}
}
Random generator = new Random();
Object[] taskValues = tasks.values().toArray();
Task taskToBeSpeculated =
(Task) taskValues[generator.nextInt(taskValues.length)];
// Other than one random task, finish every other task.
for (Map.Entry<TaskId, Task> mapTask : tasks.entrySet()) {
for (Map.Entry<TaskAttemptId, TaskAttempt> taskAttempt : mapTask
.getValue().getAttempts().entrySet()) {
if (mapTask.getKey() != taskToBeSpeculated.getID()) {
appEventHandler.handle(new TaskAttemptEvent(taskAttempt.getKey(),
TaskAttemptEventType.TA_DONE));
appEventHandler.handle(new TaskAttemptEvent(taskAttempt.getKey(),
TaskAttemptEventType.TA_CONTAINER_CLEANED));
app.waitForState(taskAttempt.getValue(), TaskAttemptState.SUCCEEDED);
}
}
}
int maxTimeWait = 10;
boolean successfullySpeculated = false;
while (maxTimeWait > 0 && !successfullySpeculated) {
if (taskToBeSpeculated.getAttempts().size() != 2) {
Thread.sleep(1000);
clock.setTime(System.currentTimeMillis() + 20000);
} else {
successfullySpeculated = true;
}
maxTimeWait--;
}
Assert
.assertTrue("Couldn't speculate successfully", successfullySpeculated);
}
@Test(timeout = 60000)
public void testSepculateSuccessfulWithUpdateEvents() throws Exception {
Clock actualClock = new SystemClock();
ControlledClock clock = new ControlledClock(actualClock);
clock.setTime(System.currentTimeMillis());
MRApp app =
new MRApp(NUM_MAPPERS, NUM_REDUCERS, false, "test", true, clock);
Job job = app.submit(new Configuration(), true, true);
app.waitForState(job, JobState.RUNNING);
Map<TaskId, Task> tasks = job.getTasks();
Assert.assertEquals("Num tasks is not correct", NUM_MAPPERS + NUM_REDUCERS,
tasks.size());
Iterator<Task> taskIter = tasks.values().iterator();
while (taskIter.hasNext()) {
app.waitForState(taskIter.next(), TaskState.RUNNING);
}
// Process the update events
clock.setTime(System.currentTimeMillis() + 1000);
EventHandler appEventHandler = app.getContext().getEventHandler();
for (Map.Entry<TaskId, Task> mapTask : tasks.entrySet()) {
for (Map.Entry<TaskAttemptId, TaskAttempt> taskAttempt : mapTask
.getValue().getAttempts().entrySet()) {
TaskAttemptStatus status =
createTaskAttemptStatus(taskAttempt.getKey(), (float) 0.5,
TaskAttemptState.RUNNING);
TaskAttemptStatusUpdateEvent event =
new TaskAttemptStatusUpdateEvent(taskAttempt.getKey(), status);
appEventHandler.handle(event);
}
}
Task speculatedTask = null;
int numTasksToFinish = NUM_MAPPERS + NUM_REDUCERS - 1;
clock.setTime(System.currentTimeMillis() + 1000);
for (Map.Entry<TaskId, Task> task : tasks.entrySet()) {
for (Map.Entry<TaskAttemptId, TaskAttempt> taskAttempt : task.getValue()
.getAttempts().entrySet()) {
if (numTasksToFinish > 0) {
appEventHandler.handle(new TaskAttemptEvent(taskAttempt.getKey(),
TaskAttemptEventType.TA_DONE));
appEventHandler.handle(new TaskAttemptEvent(taskAttempt.getKey(),
TaskAttemptEventType.TA_CONTAINER_CLEANED));
numTasksToFinish--;
app.waitForState(taskAttempt.getValue(), TaskAttemptState.SUCCEEDED);
} else {
// The last task is chosen for speculation
TaskAttemptStatus status =
createTaskAttemptStatus(taskAttempt.getKey(), (float) 0.75,
TaskAttemptState.RUNNING);
speculatedTask = task.getValue();
TaskAttemptStatusUpdateEvent event =
new TaskAttemptStatusUpdateEvent(taskAttempt.getKey(), status);
appEventHandler.handle(event);
}
}
}
clock.setTime(System.currentTimeMillis() + 15000);
for (Map.Entry<TaskId, Task> task : tasks.entrySet()) {
for (Map.Entry<TaskAttemptId, TaskAttempt> taskAttempt : task.getValue()
.getAttempts().entrySet()) {
if (taskAttempt.getValue().getState() != TaskAttemptState.SUCCEEDED) {
TaskAttemptStatus status =
createTaskAttemptStatus(taskAttempt.getKey(), (float) 0.75,
TaskAttemptState.RUNNING);
TaskAttemptStatusUpdateEvent event =
new TaskAttemptStatusUpdateEvent(taskAttempt.getKey(), status);
appEventHandler.handle(event);
}
}
}
int maxTimeWait = 5;
boolean successfullySpeculated = false;
while (maxTimeWait > 0 && !successfullySpeculated) {
if (speculatedTask.getAttempts().size() != 2) {
Thread.sleep(1000);
} else {
successfullySpeculated = true;
}
maxTimeWait--;
}
Assert
.assertTrue("Couldn't speculate successfully", successfullySpeculated);
}
private TaskAttemptStatus createTaskAttemptStatus(TaskAttemptId id,
float progress, TaskAttemptState state) {
TaskAttemptStatus status = new TaskAttemptStatus();
status.id = id;
status.progress = progress;
status.taskState = state;
return status;
}
}