MAPREDUCE-7208. Tuning TaskRuntimeEstimator. (Ahmed Hussein via jeagles)

Signed-off-by: Jonathan Eagles <jeagles@gmail.com>
(cherry picked from commit ed302f1fed)
This commit is contained in:
Ahmed Hussein 2019-11-05 14:55:20 -06:00 committed by Jonathan Eagles
parent 254e18dcaf
commit 56988e88f7
11 changed files with 1538 additions and 7 deletions

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@ -71,8 +71,22 @@ public class DataStatistics {
return count;
}
/**
* calculates the mean value within 95% ConfidenceInterval.
* 1.96 is standard for 95 %
*
* @return the mean value adding 95% confidence interval
*/
public synchronized double meanCI() {
if (count <= 1) return 0.0;
double currMean = mean();
double currStd = std();
return currMean + (1.96 * currStd / Math.sqrt(count));
}
public String toString() {
return "DataStatistics: count is " + count + ", sum is " + sum +
", sumSquares is " + sumSquares + " mean is " + mean() + " std() is " + std();
return "DataStatistics: count is " + count + ", sum is " + sum
+ ", sumSquares is " + sumSquares + " mean is " + mean()
+ " std() is " + std() + ", meanCI() is " + meanCI();
}
}

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@ -416,7 +416,8 @@ public class DefaultSpeculator extends AbstractService implements
if (estimatedRunTime == data.getEstimatedRunTime()
&& progress == data.getProgress()) {
// Previous stats are same as same stats
if (data.notHeartbeatedInAWhile(now)) {
if (data.notHeartbeatedInAWhile(now)
|| estimator.hasStagnatedProgress(runningTaskAttemptID, now)) {
// Stats have stagnated for a while, simulate heart-beat.
TaskAttemptStatus taskAttemptStatus = new TaskAttemptStatus();
taskAttemptStatus.id = runningTaskAttemptID;

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@ -0,0 +1,170 @@
/**
* 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.speculate;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.MRJobConfig;
import org.apache.hadoop.mapreduce.v2.api.records.TaskAttemptId;
import org.apache.hadoop.mapreduce.v2.api.records.TaskId;
import org.apache.hadoop.mapreduce.v2.app.AppContext;
import org.apache.hadoop.mapreduce.v2.app.job.event.TaskAttemptStatusUpdateEvent.TaskAttemptStatus;
import org.apache.hadoop.mapreduce.v2.app.speculate.forecast.SimpleExponentialSmoothing;
/**
* A task Runtime Estimator based on exponential smoothing.
*/
public class SimpleExponentialTaskRuntimeEstimator extends StartEndTimesBase {
private final static long DEFAULT_ESTIMATE_RUNTIME = -1L;
/**
* Constant time used to calculate the smoothing exponential factor.
*/
private long constTime;
/**
* Number of readings before we consider the estimate stable.
* Otherwise, the estimate will be skewed due to the initial estimate
*/
private int skipCount;
/**
* Time window to automatically update the count of the skipCount. This is
* needed when a task stalls without any progress, causing the estimator to
* return -1 as an estimatedRuntime.
*/
private long stagnatedWindow;
private final ConcurrentMap<TaskAttemptId,
AtomicReference<SimpleExponentialSmoothing>>
estimates = new ConcurrentHashMap<>();
private SimpleExponentialSmoothing getForecastEntry(TaskAttemptId attemptID) {
AtomicReference<SimpleExponentialSmoothing> entryRef = estimates
.get(attemptID);
if (entryRef == null) {
return null;
}
return entryRef.get();
}
private void incorporateReading(TaskAttemptId attemptID,
float newRawData, long newTimeStamp) {
SimpleExponentialSmoothing foreCastEntry = getForecastEntry(attemptID);
if (foreCastEntry == null) {
Long tStartTime = startTimes.get(attemptID);
// skip if the startTime is not set yet
if(tStartTime == null) {
return;
}
estimates.putIfAbsent(attemptID,
new AtomicReference<>(SimpleExponentialSmoothing.createForecast(
constTime, skipCount, stagnatedWindow,
tStartTime)));
incorporateReading(attemptID, newRawData, newTimeStamp);
return;
}
foreCastEntry.incorporateReading(newTimeStamp, newRawData);
}
@Override
public void contextualize(Configuration conf, AppContext context) {
super.contextualize(conf, context);
constTime
= conf.getLong(MRJobConfig.MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_LAMBDA_MS,
MRJobConfig.DEFAULT_MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_LAMBDA_MS);
stagnatedWindow = Math.max(2 * constTime, conf.getLong(
MRJobConfig.MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_STAGNATED_MS,
MRJobConfig.DEFAULT_MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_STAGNATED_MS));
skipCount = conf
.getInt(MRJobConfig.MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_SKIP_INITIALS,
MRJobConfig.DEFAULT_MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_INITIALS);
}
@Override
public long estimatedRuntime(TaskAttemptId id) {
SimpleExponentialSmoothing foreCastEntry = getForecastEntry(id);
if (foreCastEntry == null) {
return DEFAULT_ESTIMATE_RUNTIME;
}
// TODO: What should we do when estimate is zero
double remainingWork = Math.min(1.0, 1.0 - foreCastEntry.getRawData());
double forecast = foreCastEntry.getForecast();
if (forecast <= 0.0) {
return DEFAULT_ESTIMATE_RUNTIME;
}
long remainingTime = (long)(remainingWork / forecast);
long estimatedRuntime = remainingTime
+ foreCastEntry.getTimeStamp()
- foreCastEntry.getStartTime();
return estimatedRuntime;
}
@Override
public long estimatedNewAttemptRuntime(TaskId id) {
DataStatistics statistics = dataStatisticsForTask(id);
if (statistics == null) {
return -1L;
}
double statsMeanCI = statistics.meanCI();
double expectedVal =
statsMeanCI + Math.min(statsMeanCI * 0.25, statistics.std() / 2);
return (long)(expectedVal);
}
@Override
public boolean hasStagnatedProgress(TaskAttemptId id, long timeStamp) {
SimpleExponentialSmoothing foreCastEntry = getForecastEntry(id);
if(foreCastEntry == null) {
return false;
}
return foreCastEntry.isDataStagnated(timeStamp);
}
@Override
public long runtimeEstimateVariance(TaskAttemptId id) {
SimpleExponentialSmoothing forecastEntry = getForecastEntry(id);
if (forecastEntry == null) {
return DEFAULT_ESTIMATE_RUNTIME;
}
double forecast = forecastEntry.getForecast();
if (forecastEntry.isDefaultForecast(forecast)) {
return DEFAULT_ESTIMATE_RUNTIME;
}
//TODO: What is the best way to measure variance in runtime
return 0L;
}
@Override
public void updateAttempt(TaskAttemptStatus status, long timestamp) {
super.updateAttempt(status, timestamp);
TaskAttemptId attemptID = status.id;
float progress = status.progress;
incorporateReading(attemptID, progress, timestamp);
}
}

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@ -152,7 +152,6 @@ abstract class StartEndTimesBase implements TaskRuntimeEstimator {
if (statistics == null) {
return -1L;
}
return (long) statistics.mean();
}

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@ -87,4 +87,19 @@ public interface TaskRuntimeEstimator {
*
*/
public long runtimeEstimateVariance(TaskAttemptId id);
/**
*
* Returns true if the estimator has no updates records for a threshold time
* window. This helps to identify task attempts that are stalled at the
* beginning of execution.
*
* @param id the {@link TaskAttemptId} of the attempt we are asking about
* @param timeStamp the time of the report we compare with
* @return true if the task attempt has no progress for a given time window
*
*/
default boolean hasStagnatedProgress(TaskAttemptId id, long timeStamp) {
return false;
}
}

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@ -0,0 +1,196 @@
/**
* 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.speculate.forecast;
import java.util.concurrent.atomic.AtomicReference;
/**
* Implementation of the static model for Simple exponential smoothing.
*/
public class SimpleExponentialSmoothing {
public final static double DEFAULT_FORECAST = -1.0;
private final int kMinimumReads;
private final long kStagnatedWindow;
private final long startTime;
private long timeConstant;
private AtomicReference<ForecastRecord> forecastRefEntry;
public static SimpleExponentialSmoothing createForecast(long timeConstant,
int skipCnt, long stagnatedWindow, long timeStamp) {
return new SimpleExponentialSmoothing(timeConstant, skipCnt,
stagnatedWindow, timeStamp);
}
SimpleExponentialSmoothing(long ktConstant, int skipCnt,
long stagnatedWindow, long timeStamp) {
kMinimumReads = skipCnt;
kStagnatedWindow = stagnatedWindow;
this.timeConstant = ktConstant;
this.startTime = timeStamp;
this.forecastRefEntry = new AtomicReference<ForecastRecord>(null);
}
private class ForecastRecord {
private double alpha;
private long timeStamp;
private double sample;
private double rawData;
private double forecast;
private double sseError;
private long myIndex;
ForecastRecord(double forecast, double rawData, long timeStamp) {
this(0.0, forecast, rawData, forecast, timeStamp, 0.0, 0);
}
ForecastRecord(double alpha, double sample, double rawData,
double forecast, long timeStamp, double accError, long index) {
this.timeStamp = timeStamp;
this.alpha = alpha;
this.sseError = 0.0;
this.sample = sample;
this.forecast = forecast;
this.rawData = rawData;
this.sseError = accError;
this.myIndex = index;
}
private double preProcessRawData(double rData, long newTime) {
return processRawData(this.rawData, this.timeStamp, rData, newTime);
}
public ForecastRecord append(long newTimeStamp, double rData) {
if (this.timeStamp > newTimeStamp) {
return this;
}
double newSample = preProcessRawData(rData, newTimeStamp);
long deltaTime = this.timeStamp - newTimeStamp;
if (this.myIndex == kMinimumReads) {
timeConstant = Math.max(timeConstant, newTimeStamp - startTime);
}
double smoothFactor =
1 - Math.exp(((double) deltaTime) / timeConstant);
double forecastVal =
smoothFactor * newSample + (1.0 - smoothFactor) * this.forecast;
double newSSEError =
this.sseError + Math.pow(newSample - this.forecast, 2);
return new ForecastRecord(smoothFactor, newSample, rData, forecastVal,
newTimeStamp, newSSEError, this.myIndex + 1);
}
}
public boolean isDataStagnated(long timeStamp) {
ForecastRecord rec = forecastRefEntry.get();
if (rec != null && rec.myIndex <= kMinimumReads) {
return (rec.timeStamp + kStagnatedWindow) < timeStamp;
}
return false;
}
static double processRawData(double oldRawData, long oldTime,
double newRawData, long newTime) {
double rate = (newRawData - oldRawData) / (newTime - oldTime);
return rate;
}
public void incorporateReading(long timeStamp, double rawData) {
ForecastRecord oldRec = forecastRefEntry.get();
if (oldRec == null) {
double oldForecast =
processRawData(0, startTime, rawData, timeStamp);
forecastRefEntry.compareAndSet(null,
new ForecastRecord(oldForecast, 0.0, startTime));
incorporateReading(timeStamp, rawData);
return;
}
while (!forecastRefEntry.compareAndSet(oldRec, oldRec.append(timeStamp,
rawData))) {
oldRec = forecastRefEntry.get();
}
}
public double getForecast() {
ForecastRecord rec = forecastRefEntry.get();
if (rec != null && rec.myIndex > kMinimumReads) {
return rec.forecast;
}
return DEFAULT_FORECAST;
}
public boolean isDefaultForecast(double value) {
return value == DEFAULT_FORECAST;
}
public double getSSE() {
ForecastRecord rec = forecastRefEntry.get();
if (rec != null) {
return rec.sseError;
}
return DEFAULT_FORECAST;
}
public boolean isErrorWithinBound(double bound) {
double squaredErr = getSSE();
if (squaredErr < 0) {
return false;
}
return bound > squaredErr;
}
public double getRawData() {
ForecastRecord rec = forecastRefEntry.get();
if (rec != null) {
return rec.rawData;
}
return DEFAULT_FORECAST;
}
public long getTimeStamp() {
ForecastRecord rec = forecastRefEntry.get();
if (rec != null) {
return rec.timeStamp;
}
return 0L;
}
public long getStartTime() {
return startTime;
}
public AtomicReference<ForecastRecord> getForecastRefEntry() {
return forecastRefEntry;
}
@Override
public String toString() {
String res = "NULL";
ForecastRecord rec = forecastRefEntry.get();
if (rec != null) {
res = "rec.index = " + rec.myIndex + ", forecast t: " + rec.timeStamp +
", forecast: " + rec.forecast
+ ", sample: " + rec.sample + ", raw: " + rec.rawData + ", error: "
+ rec.sseError + ", alpha: " + rec.alpha;
}
return res;
}
}

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@ -57,6 +57,7 @@ import org.apache.hadoop.mapreduce.v2.app.job.event.TaskEventType;
import org.apache.hadoop.mapreduce.v2.app.speculate.DefaultSpeculator;
import org.apache.hadoop.mapreduce.v2.app.speculate.ExponentiallySmoothedTaskRuntimeEstimator;
import org.apache.hadoop.mapreduce.v2.app.speculate.LegacyTaskRuntimeEstimator;
import org.apache.hadoop.mapreduce.v2.app.speculate.SimpleExponentialTaskRuntimeEstimator;
import org.apache.hadoop.mapreduce.v2.app.speculate.Speculator;
import org.apache.hadoop.mapreduce.v2.app.speculate.SpeculatorEvent;
import org.apache.hadoop.mapreduce.v2.app.speculate.TaskRuntimeEstimator;
@ -257,6 +258,13 @@ public class TestRuntimeEstimators {
coreTestEstimator(specificEstimator, 3);
}
@Test
public void testSimpleExponentialEstimator() throws Exception {
TaskRuntimeEstimator specificEstimator
= new SimpleExponentialTaskRuntimeEstimator();
coreTestEstimator(specificEstimator, 3);
}
int taskTypeSlots(TaskType type) {
return type == TaskType.MAP ? MAP_SLOT_REQUIREMENT : REDUCE_SLOT_REQUIREMENT;
}

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@ -0,0 +1,120 @@
/**
* 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.speculate.forecast;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.yarn.util.ControlledClock;
import org.junit.Assert;
import org.junit.Test;
/**
* Testing the statistical model of simple exponential estimator.
*/
public class TestSimpleExponentialForecast {
private static final Log LOG =
LogFactory.getLog(TestSimpleExponentialForecast.class);
private static long clockTicks = 1000L;
private ControlledClock clock;
private int incTestSimpleExponentialForecast() {
clock = new ControlledClock();
clock.tickMsec(clockTicks);
SimpleExponentialSmoothing forecaster =
new SimpleExponentialSmoothing(10000,
12, 10000, clock.getTime());
double progress = 0.0;
while(progress <= 1.0) {
clock.tickMsec(clockTicks);
forecaster.incorporateReading(clock.getTime(), progress);
LOG.info("progress: " + progress + " --> " + forecaster.toString());
progress += 0.005;
}
return forecaster.getSSE() < Math.pow(10.0, -6) ? 0 : 1;
}
private int decTestSimpleExponentialForecast() {
clock = new ControlledClock();
clock.tickMsec(clockTicks);
SimpleExponentialSmoothing forecaster =
new SimpleExponentialSmoothing(800,
12, 10000, clock.getTime());
double progress = 0.0;
double[] progressRates = new double[]{0.005, 0.004, 0.002, 0.001};
while(progress <= 1.0) {
clock.tickMsec(clockTicks);
forecaster.incorporateReading(clock.getTime(), progress);
LOG.info("progress: " + progress + " --> " + forecaster.toString());
progress += progressRates[(int)(progress / 0.25)];
}
return forecaster.getSSE() < Math.pow(10.0, -6) ? 0 : 1;
}
private int zeroTestSimpleExponentialForecast() {
clock = new ControlledClock();
clock.tickMsec(clockTicks);
SimpleExponentialSmoothing forecaster =
new SimpleExponentialSmoothing(800,
12, 10000, clock.getTime());
double progress = 0.0;
double[] progressRates = new double[]{0.005, 0.004, 0.002, 0.0, 0.003};
int progressInd = 0;
while(progress <= 1.0) {
clock.tickMsec(clockTicks);
forecaster.incorporateReading(clock.getTime(), progress);
LOG.info("progress: " + progress + " --> " + forecaster.toString());
int currInd = progressInd++ > 1000 ? 4 : (int)(progress / 0.25);
progress += progressRates[currInd];
}
return forecaster.getSSE() < Math.pow(10.0, -6) ? 0 : 1;
}
@Test
public void testSimpleExponentialForecastLinearInc() throws Exception {
int res = incTestSimpleExponentialForecast();
Assert.assertEquals("We got the wrong estimate from simple exponential.",
res, 0);
}
@Test
public void testSimpleExponentialForecastLinearDec() throws Exception {
int res = decTestSimpleExponentialForecast();
Assert.assertEquals("We got the wrong estimate from simple exponential.",
res, 0);
}
@Test
public void testSimpleExponentialForecastZeros() throws Exception {
int res = zeroTestSimpleExponentialForecast();
Assert.assertEquals("We got the wrong estimate from simple exponential.",
res, 0);
}
}

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@ -824,6 +824,37 @@ public interface MRJobConfig {
public static final String MR_AM_TASK_ESTIMATOR_EXPONENTIAL_RATE_ENABLE =
MR_AM_PREFIX + "job.task.estimator.exponential.smooth.rate";
/** The lambda value in the smoothing function of the task estimator.*/
String MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_LAMBDA_MS =
MR_AM_PREFIX
+ "job.task.estimator.simple.exponential.smooth.lambda-ms";
long DEFAULT_MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_LAMBDA_MS = 1000L * 120;
/**
* The window length in the simple exponential smoothing that considers the
* task attempt is stagnated.
*/
String MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_STAGNATED_MS =
MR_AM_PREFIX
+ "job.task.estimator.simple.exponential.smooth.stagnated-ms";
long DEFAULT_MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_STAGNATED_MS =
1000L * 360;
/**
* The number of initial readings that the estimator ignores before giving a
* prediction. At the beginning the smooth estimator won't be accurate in
* prediction.
*/
String MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_SKIP_INITIALS =
MR_AM_PREFIX
+ "job.task.estimator.simple.exponential.smooth.skip-initials";
/**
* The default number of reading the estimators is going to ignore before
* returning the smooth exponential prediction.
*/
int DEFAULT_MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_INITIALS = 24;
/** The number of threads used to handle task RPC calls.*/
public static final String MR_AM_TASK_LISTENER_THREAD_COUNT =
MR_AM_PREFIX + "job.task.listener.thread-count";

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@ -0,0 +1,935 @@
/**
* 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.io.DataInput;
import java.io.DataOutput;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.mapreduce.Counters;
import org.apache.hadoop.mapreduce.InputFormat;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.JobCounter;
import org.apache.hadoop.mapreduce.JobStatus;
import org.apache.hadoop.mapreduce.MRJobConfig;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Partitioner;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.TaskAttemptID;
import org.apache.hadoop.mapreduce.TaskType;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.NullOutputFormat;
import org.apache.hadoop.mapreduce.v2.app.speculate.ExponentiallySmoothedTaskRuntimeEstimator;
import org.apache.hadoop.mapreduce.v2.app.speculate.LegacyTaskRuntimeEstimator;
import org.apache.hadoop.mapreduce.v2.app.speculate.SimpleExponentialTaskRuntimeEstimator;
import org.apache.hadoop.mapreduce.v2.app.speculate.TaskRuntimeEstimator;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Ignore;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
/**
* Test speculation on Mini Cluster.
*/
@Ignore
@RunWith(Parameterized.class)
public class TestSpeculativeExecOnCluster {
private static final Log LOG = LogFactory
.getLog(TestSpeculativeExecOnCluster.class);
private static final int NODE_MANAGERS_COUNT = 2;
private static final boolean ENABLE_SPECULATIVE_MAP = true;
private static final boolean ENABLE_SPECULATIVE_REDUCE = true;
private static final int NUM_MAP_DEFAULT = 8 * NODE_MANAGERS_COUNT;
private static final int NUM_REDUCE_DEFAULT = NUM_MAP_DEFAULT / 2;
private static final int MAP_SLEEP_TIME_DEFAULT = 60000;
private static final int REDUCE_SLEEP_TIME_DEFAULT = 10000;
private static final int MAP_SLEEP_COUNT_DEFAULT = 10000;
private static final int REDUCE_SLEEP_COUNT_DEFAULT = 1000;
private static final String MAP_SLEEP_COUNT =
"mapreduce.sleepjob.map.sleep.count";
private static final String REDUCE_SLEEP_COUNT =
"mapreduce.sleepjob.reduce.sleep.count";
private static final String MAP_SLEEP_TIME =
"mapreduce.sleepjob.map.sleep.time";
private static final String REDUCE_SLEEP_TIME =
"mapreduce.sleepjob.reduce.sleep.time";
private static final String MAP_SLEEP_CALCULATOR_TYPE =
"mapreduce.sleepjob.map.sleep.time.calculator";
private static final String MAP_SLEEP_CALCULATOR_TYPE_DEFAULT = "normal_run";
private static Map<String, SleepDurationCalculator> mapSleepTypeMapper;
private static FileSystem localFs;
static {
mapSleepTypeMapper = new HashMap<>();
mapSleepTypeMapper.put("normal_run", new SleepDurationCalcImpl());
mapSleepTypeMapper.put("stalled_run",
new StalledSleepDurationCalcImpl());
mapSleepTypeMapper.put("slowing_run",
new SlowingSleepDurationCalcImpl());
mapSleepTypeMapper.put("dynamic_slowing_run",
new DynamicSleepDurationCalcImpl());
mapSleepTypeMapper.put("step_stalled_run",
new StepStalledSleepDurationCalcImpl());
try {
localFs = FileSystem.getLocal(new Configuration());
} catch (IOException io) {
throw new RuntimeException("problem getting local fs", io);
}
}
private static final Path TEST_ROOT_DIR =
new Path("target",
TestSpeculativeExecOnCluster.class.getName() + "-tmpDir")
.makeQualified(localFs.getUri(), localFs.getWorkingDirectory());
private static final Path APP_JAR = new Path(TEST_ROOT_DIR, "MRAppJar.jar");
private static final Path TEST_OUT_DIR =
new Path(TEST_ROOT_DIR, "test.out.dir");
private MiniMRYarnCluster mrCluster;
private int myNumMapper;
private int myNumReduce;
private int myMapSleepTime;
private int myReduceSleepTime;
private int myMapSleepCount;
private int myReduceSleepCount;
private String chosenSleepCalc;
private Class<?> estimatorClass;
/**
* The test cases take a long time to run all the estimators against all the
* cases. We skip the legacy estimators to reduce the execution time.
*/
private List<String> ignoredTests;
@Parameterized.Parameters(name = "{index}: TaskEstimator(EstimatorClass {0})")
public static Collection<Object[]> getTestParameters() {
List<String> ignoredTests = Arrays.asList(new String[] {
"stalled_run",
"slowing_run",
"step_stalled_run"
});
return Arrays.asList(new Object[][] {
{SimpleExponentialTaskRuntimeEstimator.class, ignoredTests,
NUM_MAP_DEFAULT, NUM_REDUCE_DEFAULT},
{LegacyTaskRuntimeEstimator.class, ignoredTests,
NUM_MAP_DEFAULT, NUM_REDUCE_DEFAULT}
});
}
public TestSpeculativeExecOnCluster(
Class<? extends TaskRuntimeEstimator> estimatorKlass,
List<String> testToIgnore,
Integer numMapper,
Integer numReduce) {
this.ignoredTests = testToIgnore;
this.estimatorClass = estimatorKlass;
this.myNumMapper = numMapper;
this.myNumReduce = numReduce;
}
@Before
public void setup() throws IOException {
if (!(new File(MiniMRYarnCluster.APPJAR)).exists()) {
LOG.info("MRAppJar " + MiniMRYarnCluster.APPJAR
+ " not found. Not running test.");
return;
}
if (mrCluster == null) {
mrCluster = new MiniMRYarnCluster(
TestSpeculativeExecution.class.getName(), NODE_MANAGERS_COUNT);
Configuration conf = new Configuration();
mrCluster.init(conf);
mrCluster.start();
}
// workaround the absent public distcache.
localFs.copyFromLocalFile(new Path(MiniMRYarnCluster.APPJAR), APP_JAR);
localFs.setPermission(APP_JAR, new FsPermission("700"));
myMapSleepTime = MAP_SLEEP_TIME_DEFAULT;
myReduceSleepTime = REDUCE_SLEEP_TIME_DEFAULT;
myMapSleepCount = MAP_SLEEP_COUNT_DEFAULT;
myReduceSleepCount = REDUCE_SLEEP_COUNT_DEFAULT;
chosenSleepCalc = MAP_SLEEP_CALCULATOR_TYPE_DEFAULT;
}
@After
public void tearDown() {
if (mrCluster != null) {
mrCluster.stop();
mrCluster = null;
}
}
/**
* Overrides default behavior of Partitioner for testing.
*/
public static class SpeculativeSleepJobPartitioner extends
Partitioner<IntWritable, NullWritable> {
public int getPartition(IntWritable k, NullWritable v, int numPartitions) {
return k.get() % numPartitions;
}
}
/**
* Overrides default behavior of InputSplit for testing.
*/
public static class EmptySplit extends InputSplit implements Writable {
public void write(DataOutput out) throws IOException { }
public void readFields(DataInput in) throws IOException { }
public long getLength() {
return 0L;
}
public String[] getLocations() {
return new String[0];
}
}
/**
* Input format that sleeps after updating progress.
*/
public static class SpeculativeSleepInputFormat
extends InputFormat<IntWritable, IntWritable> {
public List<InputSplit> getSplits(JobContext jobContext) {
List<InputSplit> ret = new ArrayList<InputSplit>();
int numSplits = jobContext.getConfiguration().
getInt(MRJobConfig.NUM_MAPS, 1);
for (int i = 0; i < numSplits; ++i) {
ret.add(new EmptySplit());
}
return ret;
}
public RecordReader<IntWritable, IntWritable> createRecordReader(
InputSplit ignored, TaskAttemptContext taskContext)
throws IOException {
Configuration conf = taskContext.getConfiguration();
final int count = conf.getInt(MAP_SLEEP_COUNT, MAP_SLEEP_COUNT_DEFAULT);
if (count < 0) {
throw new IOException("Invalid map count: " + count);
}
final int redcount = conf.getInt(REDUCE_SLEEP_COUNT,
REDUCE_SLEEP_COUNT_DEFAULT);
if (redcount < 0) {
throw new IOException("Invalid reduce count: " + redcount);
}
final int emitPerMapTask = (redcount * taskContext.getNumReduceTasks());
return new RecordReader<IntWritable, IntWritable>() {
private int records = 0;
private int emitCount = 0;
private IntWritable key = null;
private IntWritable value = null;
public void initialize(InputSplit split, TaskAttemptContext context) {
}
public boolean nextKeyValue()
throws IOException {
if (count == 0) {
return false;
}
key = new IntWritable();
key.set(emitCount);
int emit = emitPerMapTask / count;
if ((emitPerMapTask) % count > records) {
++emit;
}
emitCount += emit;
value = new IntWritable();
value.set(emit);
return records++ < count;
}
public IntWritable getCurrentKey() {
return key;
}
public IntWritable getCurrentValue() {
return value;
}
public void close() throws IOException { }
public float getProgress() throws IOException {
return count == 0 ? 100 : records / ((float)count);
}
};
}
}
/**
* Interface used to simulate different progress rates of the tasks.
*/
public interface SleepDurationCalculator {
long calcSleepDuration(TaskAttemptID taId, int currCount, int totalCount,
long defaultSleepDuration);
}
/**
* All tasks have the same progress.
*/
public static class SleepDurationCalcImpl implements SleepDurationCalculator {
private double threshold = 1.0;
private double slowFactor = 1.0;
SleepDurationCalcImpl() {
}
public long calcSleepDuration(TaskAttemptID taId, int currCount,
int totalCount, long defaultSleepDuration) {
if (threshold <= ((double) currCount) / totalCount) {
return (long) (slowFactor * defaultSleepDuration);
}
return defaultSleepDuration;
}
}
/**
* The first attempt of task_0 slows down by a small factor that should not
* trigger a speculation. An speculated attempt should never beat the
* original task.
* A conservative estimator/speculator will speculate another attempt
* because of the slower progress.
*/
public static class SlowingSleepDurationCalcImpl implements
SleepDurationCalculator {
private double threshold = 0.4;
private double slowFactor = 1.2;
SlowingSleepDurationCalcImpl() {
}
public long calcSleepDuration(TaskAttemptID taId, int currCount,
int totalCount, long defaultSleepDuration) {
if ((taId.getTaskType() == TaskType.MAP)
&& (taId.getTaskID().getId() == 0) && (taId.getId() == 0)) {
if (threshold <= ((double) currCount) / totalCount) {
return (long) (slowFactor * defaultSleepDuration);
}
}
return defaultSleepDuration;
}
}
/**
* The progress of the first Mapper task is stalled by 100 times the other
* tasks.
* The speculated attempt should be succeed if the estimator detects
* the slow down on time.
*/
public static class StalledSleepDurationCalcImpl implements
SleepDurationCalculator {
StalledSleepDurationCalcImpl() {
}
public long calcSleepDuration(TaskAttemptID taId, int currCount,
int totalCount, long defaultSleepDuration) {
if ((taId.getTaskType() == TaskType.MAP)
&& (taId.getTaskID().getId() == 0) && (taId.getId() == 0)) {
return 1000 * defaultSleepDuration;
}
return defaultSleepDuration;
}
}
/**
* Emulates the behavior with a step change in the progress.
*/
public static class StepStalledSleepDurationCalcImpl implements
SleepDurationCalculator {
private double threshold = 0.4;
private double slowFactor = 10000;
StepStalledSleepDurationCalcImpl() {
}
public long calcSleepDuration(TaskAttemptID taId, int currCount,
int totalCount, long defaultSleepDuration) {
if ((taId.getTaskType() == TaskType.MAP)
&& (taId.getTaskID().getId() == 0) && (taId.getId() == 0)) {
if (threshold <= ((double) currCount) / totalCount) {
return (long) (slowFactor * defaultSleepDuration);
}
}
return defaultSleepDuration;
}
}
/**
* Dynamically slows down the progress of the first Mapper task.
* The speculated attempt should be succeed if the estimator detects
* the slow down on time.
*/
public static class DynamicSleepDurationCalcImpl implements
SleepDurationCalculator {
private double[] thresholds;
private double[] slowFactors;
DynamicSleepDurationCalcImpl() {
thresholds = new double[] {
0.1, 0.25, 0.4, 0.5, 0.6, 0.65, 0.7, 0.8, 0.9
};
slowFactors = new double[] {
2.0, 4.0, 5.0, 6.0, 10.0, 15.0, 20.0, 25.0, 30.0
};
}
public long calcSleepDuration(TaskAttemptID taId, int currCount,
int totalCount,
long defaultSleepDuration) {
if ((taId.getTaskType() == TaskType.MAP)
&& (taId.getTaskID().getId() == 0) && (taId.getId() == 0)) {
double currProgress = ((double) currCount) / totalCount;
double slowFactor = 1.0;
for (int i = 0; i < thresholds.length; i++) {
if (thresholds[i] >= currProgress) {
break;
}
slowFactor = slowFactors[i];
}
return (long) (slowFactor * defaultSleepDuration);
}
return defaultSleepDuration;
}
}
/**
* Dummy class for testing Speculation. Sleeps for a defined period
* of time in mapper. Generates fake input for map / reduce
* jobs. Note that generated number of input pairs is in the order
* of <code>numMappers * mapSleepTime / 100</code>, so the job uses
* some disk space.
* The sleep duration for a given task is going to slowDown to evaluate
* the estimator
*/
public static class SpeculativeSleepMapper
extends Mapper<IntWritable, IntWritable, IntWritable, NullWritable> {
private long mapSleepDuration = MAP_SLEEP_TIME_DEFAULT;
private int mapSleepCount = 1;
private int count = 0;
private SleepDurationCalculator sleepCalc = new SleepDurationCalcImpl();
protected void setup(Context context)
throws IOException, InterruptedException {
Configuration conf = context.getConfiguration();
this.mapSleepCount =
conf.getInt(MAP_SLEEP_COUNT, mapSleepCount);
this.mapSleepDuration = mapSleepCount == 0 ? 0 :
conf.getLong(MAP_SLEEP_TIME, MAP_SLEEP_TIME_DEFAULT) / mapSleepCount;
this.sleepCalc =
mapSleepTypeMapper.get(conf.get(MAP_SLEEP_CALCULATOR_TYPE,
MAP_SLEEP_CALCULATOR_TYPE_DEFAULT));
}
public void map(IntWritable key, IntWritable value, Context context)
throws IOException, InterruptedException {
//it is expected that every map processes mapSleepCount number of records.
try {
context.setStatus("Sleeping... (" +
(mapSleepDuration * (mapSleepCount - count)) + ") ms left");
long sleepTime = sleepCalc.calcSleepDuration(context.getTaskAttemptID(),
count, mapSleepCount,
mapSleepDuration);
Thread.sleep(sleepTime);
} catch (InterruptedException ex) {
throw (IOException) new IOException(
"Interrupted while sleeping").initCause(ex);
}
++count;
// output reduceSleepCount * numReduce number of random values, so that
// each reducer will get reduceSleepCount number of keys.
int k = key.get();
for (int i = 0; i < value.get(); ++i) {
context.write(new IntWritable(k + i), NullWritable.get());
}
}
}
/**
* Implementation of the reducer task for testing.
*/
public static class SpeculativeSleepReducer
extends Reducer<IntWritable, NullWritable, NullWritable, NullWritable> {
private long reduceSleepDuration = REDUCE_SLEEP_TIME_DEFAULT;
private int reduceSleepCount = 1;
private int count = 0;
protected void setup(Context context)
throws IOException, InterruptedException {
Configuration conf = context.getConfiguration();
this.reduceSleepCount =
conf.getInt(REDUCE_SLEEP_COUNT, reduceSleepCount);
this.reduceSleepDuration = reduceSleepCount == 0 ? 0 :
conf.getLong(REDUCE_SLEEP_TIME, REDUCE_SLEEP_TIME_DEFAULT)
/ reduceSleepCount;
}
public void reduce(IntWritable key, Iterable<NullWritable> values,
Context context)
throws IOException {
try {
context.setStatus("Sleeping... (" +
(reduceSleepDuration * (reduceSleepCount - count)) + ") ms left");
Thread.sleep(reduceSleepDuration);
} catch (InterruptedException ex) {
throw (IOException) new IOException(
"Interrupted while sleeping").initCause(ex);
}
count++;
}
}
/**
* A class used to map the estimatopr implementation to the expected
* test results.
*/
class EstimatorMetricsPair {
private Class<?> estimatorClass;
private int expectedMapTasks;
private int expectedReduceTasks;
private boolean speculativeEstimator;
EstimatorMetricsPair(Class<?> estimatorClass, int mapTasks, int reduceTasks,
boolean isToSpeculate) {
this.estimatorClass = estimatorClass;
this.expectedMapTasks = mapTasks;
this.expectedReduceTasks = reduceTasks;
this.speculativeEstimator = isToSpeculate;
}
boolean didSpeculate(Counters counters) {
long launchedMaps = counters.findCounter(JobCounter.TOTAL_LAUNCHED_MAPS)
.getValue();
long launchedReduce = counters
.findCounter(JobCounter.TOTAL_LAUNCHED_REDUCES)
.getValue();
boolean isSpeculated =
(launchedMaps > expectedMapTasks
|| launchedReduce > expectedReduceTasks);
return isSpeculated;
}
String getErrorMessage(Counters counters) {
String msg = "Unexpected tasks running estimator "
+ estimatorClass.getName() + "\n\t";
long launchedMaps = counters.findCounter(JobCounter.TOTAL_LAUNCHED_MAPS)
.getValue();
long launchedReduce = counters
.findCounter(JobCounter.TOTAL_LAUNCHED_REDUCES)
.getValue();
if (speculativeEstimator) {
if (launchedMaps < expectedMapTasks) {
msg += "maps " + launchedMaps + ", expected: " + expectedMapTasks;
}
if (launchedReduce < expectedReduceTasks) {
msg += ", reduces " + launchedReduce + ", expected: "
+ expectedReduceTasks;
}
} else {
if (launchedMaps > expectedMapTasks) {
msg += "maps " + launchedMaps + ", expected: " + expectedMapTasks;
}
if (launchedReduce > expectedReduceTasks) {
msg += ", reduces " + launchedReduce + ", expected: "
+ expectedReduceTasks;
}
}
return msg;
}
}
@Test
public void testExecDynamicSlowingSpeculative() throws Exception {
/*------------------------------------------------------------------
* Test that Map/Red speculates because:
* 1- all tasks have same progress rate except for task_0
* 2- task_0 slows down by dynamic increasing factor
* 3- A good estimator should readjust the estimation and the speculator
* launches a new task.
*
* Expected:
* A- SimpleExponentialTaskRuntimeEstimator: speculates a successful
* attempt to beat the slowing task_0
* B- LegacyTaskRuntimeEstimator: speculates an attempt
* C- ExponentiallySmoothedTaskRuntimeEstimator: Fails to detect the slow
* down and never speculates but it may speculate other tasks
* (mappers or reducers)
* -----------------------------------------------------------------
*/
chosenSleepCalc = "dynamic_slowing_run";
if (ignoredTests.contains(chosenSleepCalc)) {
return;
}
EstimatorMetricsPair[] estimatorPairs = new EstimatorMetricsPair[] {
new EstimatorMetricsPair(SimpleExponentialTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true),
new EstimatorMetricsPair(LegacyTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true),
new EstimatorMetricsPair(
ExponentiallySmoothedTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true)
};
for (EstimatorMetricsPair specEstimator : estimatorPairs) {
if (!estimatorClass.equals(specEstimator.estimatorClass)) {
continue;
}
LOG.info("+++ Dynamic Slow Progress testing against " + estimatorClass
.getName() + " +++");
Job job = runSpecTest();
boolean succeeded = job.waitForCompletion(true);
Assert.assertTrue(
"Job expected to succeed with estimator " + estimatorClass.getName(),
succeeded);
Assert.assertEquals(
"Job expected to succeed with estimator " + estimatorClass.getName(),
JobStatus.State.SUCCEEDED, job.getJobState());
Counters counters = job.getCounters();
String errorMessage = specEstimator.getErrorMessage(counters);
boolean didSpeculate = specEstimator.didSpeculate(counters);
Assert.assertEquals(errorMessage, didSpeculate,
specEstimator.speculativeEstimator);
Assert
.assertEquals("Failed maps higher than 0 " + estimatorClass.getName(),
0, counters.findCounter(JobCounter.NUM_FAILED_MAPS).getValue());
}
}
@Test
public void testExecSlowNonSpeculative() throws Exception {
/*------------------------------------------------------------------
* Test that Map/Red does not speculate because:
* 1- all tasks have same progress rate except for task_0
* 2- task_0 slows down by 0.5 after 50% of the workload
* 3- A good estimator may adjust the estimation that the task will finish
* sooner than a new speculated task.
*
* Expected:
* A- SimpleExponentialTaskRuntimeEstimator: does not speculate because
* the new attempt estimated end time is not going to be smaller than the
* original end time.
* B- LegacyTaskRuntimeEstimator: speculates an attempt
* C- ExponentiallySmoothedTaskRuntimeEstimator: speculates an attempt.
* -----------------------------------------------------------------
*/
chosenSleepCalc = "slowing_run";
if (ignoredTests.contains(chosenSleepCalc)) {
return;
}
EstimatorMetricsPair[] estimatorPairs = new EstimatorMetricsPair[] {
new EstimatorMetricsPair(SimpleExponentialTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, false),
new EstimatorMetricsPair(LegacyTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true),
new EstimatorMetricsPair(
ExponentiallySmoothedTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true)
};
for (EstimatorMetricsPair specEstimator : estimatorPairs) {
if (!estimatorClass.equals(specEstimator.estimatorClass)) {
continue;
}
LOG.info("+++ Linear Slow Progress Non Speculative testing against "
+ estimatorClass.getName() + " +++");
Job job = runSpecTest();
boolean succeeded = job.waitForCompletion(true);
Assert.assertTrue(
"Job expected to succeed with estimator " + estimatorClass.getName(),
succeeded);
Assert.assertEquals(
"Job expected to succeed with estimator " + estimatorClass.getName(),
JobStatus.State.SUCCEEDED, job.getJobState());
Counters counters = job.getCounters();
String errorMessage = specEstimator.getErrorMessage(counters);
boolean didSpeculate = specEstimator.didSpeculate(counters);
Assert.assertEquals(errorMessage, didSpeculate,
specEstimator.speculativeEstimator);
Assert
.assertEquals("Failed maps higher than 0 " + estimatorClass.getName(),
0, counters.findCounter(JobCounter.NUM_FAILED_MAPS).getValue());
}
}
@Test
public void testExecStepStalledSpeculative() throws Exception {
/*------------------------------------------------------------------
* Test that Map/Red speculates because:
* 1- all tasks have same progress rate except for task_0
* 2- task_0 has long sleep duration
* 3- A good estimator may adjust the estimation that the task will finish
* sooner than a new speculated task.
*
* Expected:
* A- SimpleExponentialTaskRuntimeEstimator: speculates
* B- LegacyTaskRuntimeEstimator: speculates
* C- ExponentiallySmoothedTaskRuntimeEstimator: speculates
* -----------------------------------------------------------------
*/
chosenSleepCalc = "step_stalled_run";
if (ignoredTests.contains(chosenSleepCalc)) {
return;
}
EstimatorMetricsPair[] estimatorPairs = new EstimatorMetricsPair[] {
new EstimatorMetricsPair(SimpleExponentialTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true),
new EstimatorMetricsPair(LegacyTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true),
new EstimatorMetricsPair(
ExponentiallySmoothedTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true)
};
for (EstimatorMetricsPair specEstimator : estimatorPairs) {
if (!estimatorClass.equals(specEstimator.estimatorClass)) {
continue;
}
LOG.info("+++ Stalled Progress testing against "
+ estimatorClass.getName() + " +++");
Job job = runSpecTest();
boolean succeeded = job.waitForCompletion(true);
Assert.assertTrue("Job expected to succeed with estimator "
+ estimatorClass.getName(), succeeded);
Assert.assertEquals("Job expected to succeed with estimator "
+ estimatorClass.getName(), JobStatus.State.SUCCEEDED,
job.getJobState());
Counters counters = job.getCounters();
String errorMessage = specEstimator.getErrorMessage(counters);
boolean didSpeculate = specEstimator.didSpeculate(counters);
Assert.assertEquals(errorMessage, didSpeculate,
specEstimator.speculativeEstimator);
Assert.assertEquals("Failed maps higher than 0 "
+ estimatorClass.getName(), 0,
counters.findCounter(JobCounter.NUM_FAILED_MAPS)
.getValue());
}
}
@Test
public void testExecStalledSpeculative() throws Exception {
/*------------------------------------------------------------------
* Test that Map/Red speculates because:
* 1- all tasks have same progress rate except for task_0
* 2- task_0 has long sleep duration
* 3- A good estimator may adjust the estimation that the task will finish
* sooner than a new speculated task.
*
* Expected:
* A- SimpleExponentialTaskRuntimeEstimator: speculates
* B- LegacyTaskRuntimeEstimator: speculates
* C- ExponentiallySmoothedTaskRuntimeEstimator: speculates
* -----------------------------------------------------------------
*/
chosenSleepCalc = "stalled_run";
if (ignoredTests.contains(chosenSleepCalc)) {
return;
}
EstimatorMetricsPair[] estimatorPairs = new EstimatorMetricsPair[] {
new EstimatorMetricsPair(SimpleExponentialTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true),
new EstimatorMetricsPair(LegacyTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true),
new EstimatorMetricsPair(
ExponentiallySmoothedTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true)
};
for (EstimatorMetricsPair specEstimator : estimatorPairs) {
if (!estimatorClass.equals(specEstimator.estimatorClass)) {
continue;
}
LOG.info("+++ Stalled Progress testing against "
+ estimatorClass.getName() + " +++");
Job job = runSpecTest();
boolean succeeded = job.waitForCompletion(true);
Assert.assertTrue("Job expected to succeed with estimator "
+ estimatorClass.getName(), succeeded);
Assert.assertEquals("Job expected to succeed with estimator "
+ estimatorClass.getName(), JobStatus.State.SUCCEEDED,
job.getJobState());
Counters counters = job.getCounters();
String errorMessage = specEstimator.getErrorMessage(counters);
boolean didSpeculate = specEstimator.didSpeculate(counters);
Assert.assertEquals(errorMessage, didSpeculate,
specEstimator.speculativeEstimator);
Assert.assertEquals("Failed maps higher than 0 "
+ estimatorClass.getName(), 0,
counters.findCounter(JobCounter.NUM_FAILED_MAPS)
.getValue());
}
}
@Test
public void testExecNonSpeculative() throws Exception {
/*------------------------------------------------------------------
* Test that Map/Red does not speculate because all tasks progress in the
* same rate.
*
* Expected:
* A- SimpleExponentialTaskRuntimeEstimator: does not speculate
* B- LegacyTaskRuntimeEstimator: speculates
* C- ExponentiallySmoothedTaskRuntimeEstimator: speculates
* -----------------------------------------------------------------
*/
if (!(new File(MiniMRYarnCluster.APPJAR)).exists()) {
LOG.info("MRAppJar " + MiniMRYarnCluster.APPJAR
+ " not found. Not running test.");
return;
}
if (ignoredTests.contains(chosenSleepCalc)) {
return;
}
EstimatorMetricsPair[] estimatorPairs = new EstimatorMetricsPair[] {
new EstimatorMetricsPair(LegacyTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true),
new EstimatorMetricsPair(SimpleExponentialTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, false),
new EstimatorMetricsPair(
ExponentiallySmoothedTaskRuntimeEstimator.class,
myNumMapper, myNumReduce, true)
};
for (EstimatorMetricsPair specEstimator : estimatorPairs) {
if (!estimatorClass.equals(specEstimator.estimatorClass)) {
continue;
}
LOG.info("+++ No Speculation testing against "
+ estimatorClass.getName() + " +++");
Job job = runSpecTest();
boolean succeeded = job.waitForCompletion(true);
Assert.assertTrue("Job expected to succeed with estimator "
+ estimatorClass.getName(), succeeded);
Assert.assertEquals("Job expected to succeed with estimator "
+ estimatorClass.getName(), JobStatus.State.SUCCEEDED,
job.getJobState());
Counters counters = job.getCounters();
String errorMessage = specEstimator.getErrorMessage(counters);
boolean didSpeculate = specEstimator.didSpeculate(counters);
Assert.assertEquals(errorMessage, didSpeculate,
specEstimator.speculativeEstimator);
}
}
private Job runSpecTest()
throws IOException, ClassNotFoundException, InterruptedException {
Configuration conf = mrCluster.getConfig();
conf.setBoolean(MRJobConfig.MAP_SPECULATIVE, ENABLE_SPECULATIVE_MAP);
conf.setBoolean(MRJobConfig.REDUCE_SPECULATIVE, ENABLE_SPECULATIVE_REDUCE);
conf.setClass(MRJobConfig.MR_AM_TASK_ESTIMATOR,
estimatorClass,
TaskRuntimeEstimator.class);
conf.setLong(MAP_SLEEP_TIME, myMapSleepTime);
conf.setLong(REDUCE_SLEEP_TIME, myReduceSleepTime);
conf.setInt(MAP_SLEEP_COUNT, myMapSleepCount);
conf.setInt(REDUCE_SLEEP_COUNT, myReduceSleepCount);
conf.setFloat(MRJobConfig.COMPLETED_MAPS_FOR_REDUCE_SLOWSTART, 1.0F);
conf.setInt(MRJobConfig.NUM_MAPS, myNumMapper);
conf.set(MAP_SLEEP_CALCULATOR_TYPE, chosenSleepCalc);
Job job = Job.getInstance(conf);
job.setJarByClass(TestSpeculativeExecution.class);
job.setMapperClass(SpeculativeSleepMapper.class);
job.setMapOutputKeyClass(IntWritable.class);
job.setMapOutputValueClass(NullWritable.class);
job.setReducerClass(SpeculativeSleepReducer.class);
job.setOutputFormatClass(NullOutputFormat.class);
job.setInputFormatClass(SpeculativeSleepInputFormat.class);
job.setPartitionerClass(SpeculativeSleepJobPartitioner.class);
job.setNumReduceTasks(myNumReduce);
FileInputFormat.addInputPath(job, new Path("ignored"));
// Delete output directory if it exists.
try {
localFs.delete(TEST_OUT_DIR, true);
} catch (IOException e) {
// ignore
}
FileOutputFormat.setOutputPath(job, TEST_OUT_DIR);
// Creates the Job Configuration
job.addFileToClassPath(APP_JAR); // The AppMaster jar itself.
job.setMaxMapAttempts(2);
job.submit();
return job;
}
}

View File

@ -18,12 +18,17 @@
package org.apache.hadoop.mapreduce.v2;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Random;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.hadoop.mapreduce.MRJobConfig;
import org.apache.hadoop.mapreduce.v2.app.speculate.LegacyTaskRuntimeEstimator;
import org.apache.hadoop.mapreduce.v2.app.speculate.SimpleExponentialTaskRuntimeEstimator;
import org.apache.hadoop.mapreduce.v2.app.speculate.TaskRuntimeEstimator;
import org.junit.Assert;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.v2.api.records.JobState;
@ -48,13 +53,31 @@ import org.apache.hadoop.yarn.util.SystemClock;
import org.junit.Test;
import com.google.common.base.Supplier;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
@SuppressWarnings({ "unchecked", "rawtypes" })
@RunWith(Parameterized.class)
public class TestSpeculativeExecutionWithMRApp {
private static final int NUM_MAPPERS = 5;
private static final int NUM_REDUCERS = 0;
@Parameterized.Parameters(name = "{index}: TaskEstimator(EstimatorClass {0})")
public static Collection<Object[]> getTestParameters() {
return Arrays.asList(new Object[][] {
{SimpleExponentialTaskRuntimeEstimator.class},
{LegacyTaskRuntimeEstimator.class}
});
}
private Class<? extends TaskRuntimeEstimator> estimatorClass;
public TestSpeculativeExecutionWithMRApp(
Class<? extends TaskRuntimeEstimator> estimatorKlass) {
this.estimatorClass = estimatorKlass;
}
@Test
public void testSpeculateSuccessfulWithoutUpdateEvents() throws Exception {
@ -64,7 +87,7 @@ public class TestSpeculativeExecutionWithMRApp {
MRApp app =
new MRApp(NUM_MAPPERS, NUM_REDUCERS, false, "test", true, clock);
Job job = app.submit(new Configuration(), true, true);
Job job = app.submit(createConfiguration(), true, true);
app.waitForState(job, JobState.RUNNING);
Map<TaskId, Task> tasks = job.getTasks();
@ -136,7 +159,7 @@ public class TestSpeculativeExecutionWithMRApp {
MRApp app =
new MRApp(NUM_MAPPERS, NUM_REDUCERS, false, "test", true, clock);
Job job = app.submit(new Configuration(), true, true);
Job job = app.submit(createConfiguration(), true, true);
app.waitForState(job, JobState.RUNNING);
Map<TaskId, Task> tasks = job.getTasks();
@ -191,6 +214,9 @@ public class TestSpeculativeExecutionWithMRApp {
}
clock.setTime(System.currentTimeMillis() + 15000);
// give a chance to the speculator thread to run a scan before we proceed
// with updating events
Thread.yield();
for (Map.Entry<TaskId, Task> task : tasks.entrySet()) {
for (Map.Entry<TaskAttemptId, TaskAttempt> taskAttempt : task.getValue()
.getAttempts().entrySet()) {
@ -251,4 +277,20 @@ public class TestSpeculativeExecutionWithMRApp {
status.taskState = state;
return status;
}
private Configuration createConfiguration() {
Configuration conf = new Configuration();
conf.setClass(MRJobConfig.MR_AM_TASK_ESTIMATOR,
estimatorClass,
TaskRuntimeEstimator.class);
if (SimpleExponentialTaskRuntimeEstimator.class.equals(estimatorClass)) {
// set configurations specific to SimpleExponential estimator
conf.setInt(
MRJobConfig.MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_SKIP_INITIALS, 1);
conf.setLong(
MRJobConfig.MR_AM_TASK_ESTIMATOR_SIMPLE_SMOOTH_LAMBDA_MS,
1000L * 10);
}
return conf;
}
}