Author: acmurthy
Date: Fri Jul 25 11:57:12 2008
New Revision: 679879
URL: http://svn.apache.org/viewvc?rev=679879&view=rev
Log:
HADOOP-3820. Fixed compression of empty map-outputs.
Added:
hadoop/core/trunk/src/test/org/apache/hadoop/mapred/TestCompressedEmptyMapOutputs.java
Modified:
hadoop/core/trunk/CHANGES.txt
hadoop/core/trunk/src/mapred/org/apache/hadoop/mapred/MapTask.java
Modified: hadoop/core/trunk/CHANGES.txt
URL:
http://svn.apache.org/viewvc/hadoop/core/trunk/CHANGES.txt?rev=679879&r1=679878&r2=679879&view=diff
==============================================================================
--- hadoop/core/trunk/CHANGES.txt (original)
+++ hadoop/core/trunk/CHANGES.txt Fri Jul 25 11:57:12 2008
@@ -949,6 +949,8 @@
HADOOP-3724. Fixes two problems related to storing and recovering lease
in the fsimage. (dhruba)
+
+ HADOOP-3827. Fixed compression of empty map-outputs.
Release 0.17.2 - Unreleased
Modified: hadoop/core/trunk/src/mapred/org/apache/hadoop/mapred/MapTask.java
URL:
http://svn.apache.org/viewvc/hadoop/core/trunk/src/mapred/org/apache/hadoop/mapred/MapTask.java?rev=679879&r1=679878&r2=679879&view=diff
==============================================================================
--- hadoop/core/trunk/src/mapred/org/apache/hadoop/mapred/MapTask.java
(original)
+++ hadoop/core/trunk/src/mapred/org/apache/hadoop/mapred/MapTask.java Fri Jul
25 11:57:12 2008
@@ -1057,7 +1057,7 @@
for (int i = 0; i < partitions; i++) {
long segmentStart = finalOut.getPos();
Writer<K, V> writer = new Writer<K, V>(job, finalOut,
- keyClass, valClass, null);
+ keyClass, valClass, codec);
writer.close();
writeIndexRecord(finalIndexOut, finalOut, segmentStart, writer);
}
Added:
hadoop/core/trunk/src/test/org/apache/hadoop/mapred/TestCompressedEmptyMapOutputs.java
URL:
http://svn.apache.org/viewvc/hadoop/core/trunk/src/test/org/apache/hadoop/mapred/TestCompressedEmptyMapOutputs.java?rev=679879&view=auto
==============================================================================
---
hadoop/core/trunk/src/test/org/apache/hadoop/mapred/TestCompressedEmptyMapOutputs.java
(added)
+++
hadoop/core/trunk/src/test/org/apache/hadoop/mapred/TestCompressedEmptyMapOutputs.java
Fri Jul 25 11:57:12 2008
@@ -0,0 +1,123 @@
+/**
+ * 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 java.io.IOException;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.examples.RandomWriter;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.io.BytesWritable;
+import org.apache.hadoop.mapred.lib.IdentityReducer;
+import org.apache.hadoop.util.ToolRunner;
+
+import junit.framework.TestCase;
+
+/**
+ * A JUnit test to test the Map-Reduce framework's sort in presence of
+ * null intermediate map-outputs, when compression is enabled for intermediate
+ * map-outputs.
+ */
+public class TestCompressedEmptyMapOutputs extends TestCase {
+ // Input/Output paths for sort
+ private static final Path SORT_INPUT_PATH = new Path("/sort/input");
+ private static final Path SORT_OUTPUT_PATH = new Path("/sort/output");
+
+ // Knobs to control randomwriter; and hence sort
+ private static final int NUM_HADOOP_SLAVES = 3;
+ private static final int RW_BYTES_PER_MAP = 50000;
+ private static final int RW_MAPS_PER_HOST = 5;
+
+ private static void runRandomWriter(JobConf job, Path sortInput)
+ throws Exception {
+ // Scale down the default settings for RandomWriter for the test-case
+ // Generates NUM_HADOOP_SLAVES * RW_MAPS_PER_HOST * RW_BYTES_PER_MAP -> 1MB
+ job.setInt("test.randomwrite.bytes_per_map", RW_BYTES_PER_MAP);
+ job.setInt("test.randomwriter.maps_per_host", RW_MAPS_PER_HOST);
+ String[] rwArgs = {sortInput.toString()};
+
+ // Run RandomWriter
+ assertEquals(ToolRunner.run(job, new RandomWriter(), rwArgs), 0);
+ }
+
+
+ static class SinkMapper<K, V>
+ extends MapReduceBase implements Mapper<K, V, K, V> {
+
+ public void map(K key, V val,
+ OutputCollector<K, V> output, Reporter reporter)
+ throws IOException {
+ // Don't output anything!
+ if (false) output.collect(key, val);
+ }
+ }
+
+ private static void runSort(JobConf jobConf, Path sortInput, Path
sortOutput)
+ throws Exception {
+ // Set up the job
+ jobConf.setJobName("null-sorter");
+
+ jobConf.setMapperClass(SinkMapper.class);
+ jobConf.setReducerClass(IdentityReducer.class);
+
+ jobConf.setNumReduceTasks(2);
+
+ jobConf.setInputFormat(SequenceFileInputFormat.class);
+ jobConf.setOutputFormat(SequenceFileOutputFormat.class);
+
+ jobConf.setOutputKeyClass(BytesWritable.class);
+ jobConf.setOutputValueClass(BytesWritable.class);
+
+ FileInputFormat.setInputPaths(jobConf, sortInput);
+ FileOutputFormat.setOutputPath(jobConf, sortOutput);
+
+ // Compress the intermediate map-outputs!
+ jobConf.setCompressMapOutput(true);
+
+ // Run the job
+ JobClient.runJob(jobConf);
+ }
+
+ public void testMapReduceSortWithCompressedEmptyMapOutputs()
+ throws Exception {
+ MiniDFSCluster dfs = null;
+ MiniMRCluster mr = null;
+ FileSystem fileSys = null;
+ try {
+ Configuration conf = new Configuration();
+
+ // Start the mini-MR and mini-DFS clusters
+ dfs = new MiniDFSCluster(conf, NUM_HADOOP_SLAVES, true, null);
+ fileSys = dfs.getFileSystem();
+ mr = new MiniMRCluster(NUM_HADOOP_SLAVES, fileSys.getUri().toString(),
1);
+
+ // Run randomwriter to generate input for 'sort'
+ runRandomWriter(mr.createJobConf(), SORT_INPUT_PATH);
+
+ // Run sort
+ runSort(mr.createJobConf(), SORT_INPUT_PATH, SORT_OUTPUT_PATH);
+ } finally {
+ if (dfs != null) { dfs.shutdown(); }
+ if (mr != null) { mr.shutdown();
+ }
+ }
+ }
+
+}
