MAPREDUCE-3310. Custom grouping comparator cannot be set for Combiners (tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1555969 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Alejandro Abdelnur 2014-01-06 18:37:40 +00:00
parent c1d92ca03e
commit 47469c464c
14 changed files with 493 additions and 9 deletions

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@ -50,6 +50,8 @@ Release 2.4.0 - UNRELEASED
MAPREDUCE-5550. Task Status message (reporter.setStatus) not shown in UI
with Hadoop 2.0 (Gera Shegalov via Sandy Ryza)
MAPREDUCE-3310. Custom grouping comparator cannot be set for Combiners (tucu)
OPTIMIZATIONS
MAPREDUCE-5484. YarnChild unnecessarily loads job conf twice (Sandy Ryza)

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@ -949,6 +949,23 @@ public class JobConf extends Configuration {
return get(KeyFieldBasedPartitioner.PARTITIONER_OPTIONS);
}
/**
* Get the user defined {@link WritableComparable} comparator for
* grouping keys of inputs to the combiner.
*
* @return comparator set by the user for grouping values.
* @see #setCombinerKeyGroupingComparator(Class) for details.
*/
public RawComparator getCombinerKeyGroupingComparator() {
Class<? extends RawComparator> theClass = getClass(
JobContext.COMBINER_GROUP_COMPARATOR_CLASS, null, RawComparator.class);
if (theClass == null) {
return getOutputKeyComparator();
}
return ReflectionUtils.newInstance(theClass, this);
}
/**
* Get the user defined {@link WritableComparable} comparator for
* grouping keys of inputs to the reduce.
@ -966,6 +983,37 @@ public class JobConf extends Configuration {
return ReflectionUtils.newInstance(theClass, this);
}
/**
* Set the user defined {@link RawComparator} comparator for
* grouping keys in the input to the combiner.
* <p/>
* <p>This comparator should be provided if the equivalence rules for keys
* for sorting the intermediates are different from those for grouping keys
* before each call to
* {@link Reducer#reduce(Object, java.util.Iterator, OutputCollector, Reporter)}.</p>
* <p/>
* <p>For key-value pairs (K1,V1) and (K2,V2), the values (V1, V2) are passed
* in a single call to the reduce function if K1 and K2 compare as equal.</p>
* <p/>
* <p>Since {@link #setOutputKeyComparatorClass(Class)} can be used to control
* how keys are sorted, this can be used in conjunction to simulate
* <i>secondary sort on values</i>.</p>
* <p/>
* <p><i>Note</i>: This is not a guarantee of the combiner sort being
* <i>stable</i> in any sense. (In any case, with the order of available
* map-outputs to the combiner being non-deterministic, it wouldn't make
* that much sense.)</p>
*
* @param theClass the comparator class to be used for grouping keys for the
* combiner. It should implement <code>RawComparator</code>.
* @see #setOutputKeyComparatorClass(Class)
*/
public void setCombinerKeyGroupingComparator(
Class<? extends RawComparator> theClass) {
setClass(JobContext.COMBINER_GROUP_COMPARATOR_CLASS,
theClass, RawComparator.class);
}
/**
* Set the user defined {@link RawComparator} comparator for
* grouping keys in the input to the reduce.
@ -989,7 +1037,9 @@ public class JobConf extends Configuration {
*
* @param theClass the comparator class to be used for grouping keys.
* It should implement <code>RawComparator</code>.
* @see #setOutputKeyComparatorClass(Class)
* @see #setOutputKeyComparatorClass(Class)
* @see {@link #setCombinerKeyGroupingComparator(Class)} for setting a
* comparator for the combiner.
*/
public void setOutputValueGroupingComparator(
Class<? extends RawComparator> theClass) {

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@ -1553,7 +1553,8 @@ abstract public class Task implements Writable, Configurable {
combinerClass = cls;
keyClass = (Class<K>) job.getMapOutputKeyClass();
valueClass = (Class<V>) job.getMapOutputValueClass();
comparator = (RawComparator<K>) job.getOutputKeyComparator();
comparator = (RawComparator<K>)
job.getCombinerKeyGroupingComparator();
}
@SuppressWarnings("unchecked")
@ -1602,7 +1603,7 @@ abstract public class Task implements Writable, Configurable {
this.taskId = taskId;
keyClass = (Class<K>) context.getMapOutputKeyClass();
valueClass = (Class<V>) context.getMapOutputValueClass();
comparator = (RawComparator<K>) context.getSortComparator();
comparator = (RawComparator<K>) context.getCombinerKeyGroupingComparator();
this.committer = committer;
}

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@ -948,11 +948,27 @@ public class Job extends JobContextImpl implements JobContext {
conf.setOutputValueClass(theClass);
}
/**
* Define the comparator that controls which keys are grouped together
* for a single call to combiner,
* {@link Reducer#reduce(Object, Iterable,
* org.apache.hadoop.mapreduce.Reducer.Context)}
*
* @param cls the raw comparator to use
* @throws IllegalStateException if the job is submitted
*/
public void setCombinerKeyGroupingComparatorClass(
Class<? extends RawComparator> cls) throws IllegalStateException {
ensureState(JobState.DEFINE);
conf.setCombinerKeyGroupingComparator(cls);
}
/**
* Define the comparator that controls how the keys are sorted before they
* are passed to the {@link Reducer}.
* @param cls the raw comparator
* @throws IllegalStateException if the job is submitted
* @see {@link #setCombinerKeyGroupingComparatorClass(Class)}
*/
public void setSortComparatorClass(Class<? extends RawComparator> cls
) throws IllegalStateException {
@ -967,6 +983,8 @@ public class Job extends JobContextImpl implements JobContext {
* org.apache.hadoop.mapreduce.Reducer.Context)}
* @param cls the raw comparator to use
* @throws IllegalStateException if the job is submitted
* @see {@link #setCombinerKeyGroupingComparatorClass(Class)} for setting a
* comparator for the combiner.
*/
public void setGroupingComparatorClass(Class<? extends RawComparator> cls
) throws IllegalStateException {

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@ -167,13 +167,24 @@ public interface JobContext extends MRJobConfig {
*/
public String getJar();
/**
* Get the user defined {@link RawComparator} comparator for
* grouping keys of inputs to the reduce.
*
/**
* Get the user defined {@link RawComparator} comparator for
* grouping keys of inputs to the combiner.
*
* @return comparator set by the user for grouping values.
* @see Job#setGroupingComparatorClass(Class) for details.
* @see Job#setCombinerKeyGroupingComparatorClass(Class) for details.
*/
public RawComparator<?> getCombinerKeyGroupingComparator();
/**
* Get the user defined {@link RawComparator} comparator for
* grouping keys of inputs to the reduce.
*
* @return comparator set by the user for grouping values.
* @see Job#setGroupingComparatorClass(Class) for details.
* @see {@link #getCombinerKeyGroupingComparator()} for setting a
* comparator for the combiner.
*/
public RawComparator<?> getGroupingComparator();
/**

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@ -93,6 +93,8 @@ public interface MRJobConfig {
public static final String KEY_COMPARATOR = "mapreduce.job.output.key.comparator.class";
public static final String COMBINER_GROUP_COMPARATOR_CLASS = "mapreduce.job.combiner.group.comparator.class";
public static final String GROUP_COMPARATOR_CLASS = "mapreduce.job.output.group.comparator.class";
public static final String WORKING_DIR = "mapreduce.job.working.dir";

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@ -166,6 +166,11 @@ class ChainMapContextImpl<KEYIN, VALUEIN, KEYOUT, VALUEOUT> implements
return base.getFileTimestamps();
}
@Override
public RawComparator<?> getCombinerKeyGroupingComparator() {
return base.getCombinerKeyGroupingComparator();
}
@Override
public RawComparator<?> getGroupingComparator() {
return base.getGroupingComparator();

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@ -159,6 +159,11 @@ class ChainReduceContextImpl<KEYIN, VALUEIN, KEYOUT, VALUEOUT> implements
return base.getFileTimestamps();
}
@Override
public RawComparator<?> getCombinerKeyGroupingComparator() {
return base.getCombinerKeyGroupingComparator();
}
@Override
public RawComparator<?> getGroupingComparator() {
return base.getGroupingComparator();

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@ -168,6 +168,11 @@ public class WrappedMapper<KEYIN, VALUEIN, KEYOUT, VALUEOUT>
return mapContext.getFileTimestamps();
}
@Override
public RawComparator<?> getCombinerKeyGroupingComparator() {
return mapContext.getCombinerKeyGroupingComparator();
}
@Override
public RawComparator<?> getGroupingComparator() {
return mapContext.getGroupingComparator();

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@ -161,6 +161,11 @@ public class WrappedReducer<KEYIN, VALUEIN, KEYOUT, VALUEOUT>
return reduceContext.getFileTimestamps();
}
@Override
public RawComparator<?> getCombinerKeyGroupingComparator() {
return reduceContext.getCombinerKeyGroupingComparator();
}
@Override
public RawComparator<?> getGroupingComparator() {
return reduceContext.getGroupingComparator();

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@ -252,6 +252,17 @@ public class JobContextImpl implements JobContext {
return conf.getJar();
}
/**
* Get the user defined {@link RawComparator} comparator for
* grouping keys of inputs to the combiner.
*
* @return comparator set by the user for grouping values.
* @see Job#setCombinerKeyGroupingComparatorClass(Class) for details.
*/
public RawComparator<?> getCombinerKeyGroupingComparator() {
return conf.getCombinerKeyGroupingComparator();
}
/**
* Get the user defined {@link RawComparator} comparator for
* grouping keys of inputs to the reduce.

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@ -582,7 +582,7 @@ public class MergeManagerImpl<K, V> implements MergeManager<K, V> {
Class<K> keyClass = (Class<K>) job.getMapOutputKeyClass();
Class<V> valClass = (Class<V>) job.getMapOutputValueClass();
RawComparator<K> comparator =
(RawComparator<K>)job.getOutputKeyComparator();
(RawComparator<K>)job.getCombinerKeyGroupingComparator();
try {
CombineValuesIterator values = new CombineValuesIterator(
kvIter, comparator, keyClass, valClass, job, Reporter.NULL,

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@ -0,0 +1,191 @@
/**
* 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.mapred;
import junit.framework.Assert;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.RawComparator;
import org.apache.hadoop.io.Text;
import org.junit.Test;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import java.util.UUID;
public class TestOldCombinerGrouping {
private static String TEST_ROOT_DIR =
new File("build", UUID.randomUUID().toString()).getAbsolutePath();
public static class Map implements
Mapper<LongWritable, Text, Text, LongWritable> {
@Override
public void map(LongWritable key, Text value,
OutputCollector<Text, LongWritable> output, Reporter reporter)
throws IOException {
String v = value.toString();
String k = v.substring(0, v.indexOf(","));
v = v.substring(v.indexOf(",") + 1);
output.collect(new Text(k), new LongWritable(Long.parseLong(v)));
}
@Override
public void close() throws IOException {
}
@Override
public void configure(JobConf job) {
}
}
public static class Reduce implements
Reducer<Text, LongWritable, Text, LongWritable> {
@Override
public void reduce(Text key, Iterator<LongWritable> values,
OutputCollector<Text, LongWritable> output, Reporter reporter)
throws IOException {
LongWritable maxValue = null;
while (values.hasNext()) {
LongWritable value = values.next();
if (maxValue == null) {
maxValue = value;
} else if (value.compareTo(maxValue) > 0) {
maxValue = value;
}
}
output.collect(key, maxValue);
}
@Override
public void close() throws IOException {
}
@Override
public void configure(JobConf job) {
}
}
public static class Combiner extends Reduce {
}
public static class GroupComparator implements RawComparator<Text> {
@Override
public int compare(byte[] bytes, int i, int i2, byte[] bytes2, int i3,
int i4) {
byte[] b1 = new byte[i2];
System.arraycopy(bytes, i, b1, 0, i2);
byte[] b2 = new byte[i4];
System.arraycopy(bytes2, i3, b2, 0, i4);
return compare(new Text(new String(b1)), new Text(new String(b2)));
}
@Override
public int compare(Text o1, Text o2) {
String s1 = o1.toString();
String s2 = o2.toString();
s1 = s1.substring(0, s1.indexOf("|"));
s2 = s2.substring(0, s2.indexOf("|"));
return s1.compareTo(s2);
}
}
@Test
public void testCombiner() throws Exception {
if (!new File(TEST_ROOT_DIR).mkdirs()) {
throw new RuntimeException("Could not create test dir: " + TEST_ROOT_DIR);
}
File in = new File(TEST_ROOT_DIR, "input");
if (!in.mkdirs()) {
throw new RuntimeException("Could not create test dir: " + in);
}
File out = new File(TEST_ROOT_DIR, "output");
PrintWriter pw = new PrintWriter(new FileWriter(new File(in, "data.txt")));
pw.println("A|a,1");
pw.println("A|b,2");
pw.println("B|a,3");
pw.println("B|b,4");
pw.println("B|c,5");
pw.close();
JobConf job = new JobConf();
job.set("mapreduce.framework.name", "local");
TextInputFormat.setInputPaths(job, new Path(in.getPath()));
TextOutputFormat.setOutputPath(job, new Path(out.getPath()));
job.setMapperClass(Map.class);
job.setReducerClass(Reduce.class);
job.setInputFormat(TextInputFormat.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(LongWritable.class);
job.setOutputFormat(TextOutputFormat.class);
job.setOutputValueGroupingComparator(GroupComparator.class);
job.setCombinerClass(Combiner.class);
job.setCombinerKeyGroupingComparator(GroupComparator.class);
job.setInt("min.num.spills.for.combine", 0);
JobClient client = new JobClient(job);
RunningJob runningJob = client.submitJob(job);
runningJob.waitForCompletion();
if (runningJob.isSuccessful()) {
Counters counters = runningJob.getCounters();
long combinerInputRecords = counters.getGroup(
"org.apache.hadoop.mapreduce.TaskCounter").
getCounter("COMBINE_INPUT_RECORDS");
long combinerOutputRecords = counters.getGroup(
"org.apache.hadoop.mapreduce.TaskCounter").
getCounter("COMBINE_OUTPUT_RECORDS");
Assert.assertTrue(combinerInputRecords > 0);
Assert.assertTrue(combinerInputRecords > combinerOutputRecords);
BufferedReader br = new BufferedReader(new FileReader(
new File(out, "part-00000")));
Set<String> output = new HashSet<String>();
String line = br.readLine();
Assert.assertNotNull(line);
output.add(line.substring(0, 1) + line.substring(4, 5));
line = br.readLine();
Assert.assertNotNull(line);
output.add(line.substring(0, 1) + line.substring(4, 5));
line = br.readLine();
Assert.assertNull(line);
br.close();
Set<String> expected = new HashSet<String>();
expected.add("A2");
expected.add("B5");
Assert.assertEquals(expected, output);
} else {
Assert.fail("Job failed");
}
}
}

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@ -0,0 +1,178 @@
/**
* 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;
import junit.framework.Assert;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.RawComparator;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.junit.Test;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashSet;
import java.util.Set;
import java.util.UUID;
public class TestNewCombinerGrouping {
private static String TEST_ROOT_DIR =
new File("build", UUID.randomUUID().toString()).getAbsolutePath();
public static class Map extends
Mapper<LongWritable, Text, Text, LongWritable> {
@Override
protected void map(LongWritable key, Text value,
Context context)
throws IOException, InterruptedException {
String v = value.toString();
String k = v.substring(0, v.indexOf(","));
v = v.substring(v.indexOf(",") + 1);
context.write(new Text(k), new LongWritable(Long.parseLong(v)));
}
}
public static class Reduce extends
Reducer<Text, LongWritable, Text, LongWritable> {
@Override
protected void reduce(Text key, Iterable<LongWritable> values,
Context context)
throws IOException, InterruptedException {
LongWritable maxValue = null;
for (LongWritable value : values) {
if (maxValue == null) {
maxValue = value;
} else if (value.compareTo(maxValue) > 0) {
maxValue = value;
}
}
context.write(key, maxValue);
}
}
public static class Combiner extends Reduce {
}
public static class GroupComparator implements RawComparator<Text> {
@Override
public int compare(byte[] bytes, int i, int i2, byte[] bytes2, int i3,
int i4) {
byte[] b1 = new byte[i2];
System.arraycopy(bytes, i, b1, 0, i2);
byte[] b2 = new byte[i4];
System.arraycopy(bytes2, i3, b2, 0, i4);
return compare(new Text(new String(b1)), new Text(new String(b2)));
}
@Override
public int compare(Text o1, Text o2) {
String s1 = o1.toString();
String s2 = o2.toString();
s1 = s1.substring(0, s1.indexOf("|"));
s2 = s2.substring(0, s2.indexOf("|"));
return s1.compareTo(s2);
}
}
@Test
public void testCombiner() throws Exception {
if (!new File(TEST_ROOT_DIR).mkdirs()) {
throw new RuntimeException("Could not create test dir: " + TEST_ROOT_DIR);
}
File in = new File(TEST_ROOT_DIR, "input");
if (!in.mkdirs()) {
throw new RuntimeException("Could not create test dir: " + in);
}
File out = new File(TEST_ROOT_DIR, "output");
PrintWriter pw = new PrintWriter(new FileWriter(new File(in, "data.txt")));
pw.println("A|a,1");
pw.println("A|b,2");
pw.println("B|a,3");
pw.println("B|b,4");
pw.println("B|c,5");
pw.close();
JobConf conf = new JobConf();
conf.set("mapreduce.framework.name", "local");
Job job = new Job(conf);
TextInputFormat.setInputPaths(job, new Path(in.getPath()));
TextOutputFormat.setOutputPath(job, new Path(out.getPath()));
job.setMapperClass(Map.class);
job.setReducerClass(Reduce.class);
job.setInputFormatClass(TextInputFormat.class);
job.setMapOutputKeyClass(Text.class);
job.setMapOutputValueClass(LongWritable.class);
job.setOutputFormatClass(TextOutputFormat.class);
job.setGroupingComparatorClass(GroupComparator.class);
job.setCombinerKeyGroupingComparatorClass(GroupComparator.class);
job.setCombinerClass(Combiner.class);
job.getConfiguration().setInt("min.num.spills.for.combine", 0);
job.submit();
job.waitForCompletion(false);
if (job.isSuccessful()) {
Counters counters = job.getCounters();
long combinerInputRecords = counters.findCounter(
"org.apache.hadoop.mapreduce.TaskCounter",
"COMBINE_INPUT_RECORDS").getValue();
long combinerOutputRecords = counters.findCounter(
"org.apache.hadoop.mapreduce.TaskCounter",
"COMBINE_OUTPUT_RECORDS").getValue();
Assert.assertTrue(combinerInputRecords > 0);
Assert.assertTrue(combinerInputRecords > combinerOutputRecords);
BufferedReader br = new BufferedReader(new FileReader(
new File(out, "part-r-00000")));
Set<String> output = new HashSet<String>();
String line = br.readLine();
Assert.assertNotNull(line);
output.add(line.substring(0, 1) + line.substring(4, 5));
line = br.readLine();
Assert.assertNotNull(line);
output.add(line.substring(0, 1) + line.substring(4, 5));
line = br.readLine();
Assert.assertNull(line);
br.close();
Set<String> expected = new HashSet<String>();
expected.add("A2");
expected.add("B5");
Assert.assertEquals(expected, output);
} else {
Assert.fail("Job failed");
}
}
}