/**
* 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 java.util.Arrays;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import junit.extensions.TestSetup;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.TestMapCollection.FakeIF;
import org.apache.hadoop.mapred.TestMapCollection.FakeSplit;
import org.apache.hadoop.mapred.lib.IdentityReducer;
public class TestReduceFetch extends TestCase {
private static MiniMRCluster mrCluster = null;
private static MiniDFSCluster dfsCluster = null;
public static Test suite() {
TestSetup setup = new TestSetup(new TestSuite(TestReduceFetch.class)) {
protected void setUp() throws Exception {
Configuration conf = new Configuration();
dfsCluster = new MiniDFSCluster(conf, 2, true, null);
mrCluster = new MiniMRCluster(2,
dfsCluster.getFileSystem().getUri().toString(), 1);
}
protected void tearDown() throws Exception {
if (dfsCluster != null) { dfsCluster.shutdown(); }
if (mrCluster != null) { mrCluster.shutdown(); }
}
};
return setup;
}
public static class MapMB
implements Mapper<NullWritable,NullWritable,Text,Text> {
public void map(NullWritable nk, NullWritable nv,
OutputCollector<Text, Text> output, Reporter reporter)
throws IOException {
Text key = new Text();
Text val = new Text();
key.set("KEYKEYKEYKEYKEYKEYKEYKEY");
byte[] b = new byte[1000];
Arrays.fill(b, (byte)'V');
val.set(b);
b = null;
for (int i = 0; i < 4 * 1024; ++i) {
output.collect(key, val);
}
}
public void configure(JobConf conf) { }
public void close() throws IOException { }
}
public static Counters runJob(JobConf conf) throws Exception {
conf.setMapperClass(MapMB.class);
conf.setReducerClass(IdentityReducer.class);
conf.setOutputKeyClass(Text.class);
conf.setOutputValueClass(Text.class);
conf.setNumReduceTasks(1);
conf.setInputFormat(FakeIF.class);
FileInputFormat.setInputPaths(conf, new Path("/in"));
final Path outp = new Path("/out");
FileOutputFormat.setOutputPath(conf, outp);
RunningJob job = null;
try {
job = JobClient.runJob(conf);
assertTrue(job.isSuccessful());
} finally {
FileSystem fs = dfsCluster.getFileSystem();
if (fs.exists(outp)) {
fs.delete(outp, true);
}
}
return job.getCounters();
}
public void testReduceFromDisk() throws Exception {
final int MAP_TASKS = 8;
JobConf job = mrCluster.createJobConf();
job.set("mapred.job.reduce.input.buffer.percent", "0.0");
job.setNumMapTasks(MAP_TASKS);
job.setInt("mapred.job.reduce.total.mem.bytes", 128 << 20);
job.set("mapred.job.shuffle.input.buffer.percent", "0.05");
job.setInt("io.sort.factor", 2);
job.setInt("mapred.inmem.merge.threshold", 4);
Counters c = runJob(job);
final long spill = c.findCounter(Task.Counter.SPILLED_RECORDS).getCounter();
final long out = c.findCounter(Task.Counter.MAP_OUTPUT_RECORDS).getCounter();
assertTrue("Expected all records spilled during reduce (" + spill + ")",
spill >= 2 * out); // all records spill at map, reduce
assertTrue("Expected intermediate merges (" + spill + ")",
spill >= 2 * out + (out / MAP_TASKS)); // some records hit twice
}
public void testReduceFromPartialMem() throws Exception {
final int MAP_TASKS = 7;
JobConf job = mrCluster.createJobConf();
job.setNumMapTasks(MAP_TASKS);
job.setInt("mapred.inmem.merge.threshold", 0);
job.set("mapred.job.reduce.input.buffer.percent", "1.0");
job.setInt("mapred.reduce.parallel.copies", 1);
job.setInt("io.sort.mb", 10);
job.setInt("mapred.job.reduce.total.mem.bytes", 128 << 20);
job.set(JobConf.MAPRED_REDUCE_TASK_JAVA_OPTS, "-Xmx128m");
job.set("mapred.job.shuffle.input.buffer.percent", "0.14");
job.setNumTasksToExecutePerJvm(1);
job.set("mapred.job.shuffle.merge.percent", "1.0");
Counters c = runJob(job);
final long out = c.findCounter(Task.Counter.MAP_OUTPUT_RECORDS).getCounter();
final long spill = c.findCounter(Task.Counter.SPILLED_RECORDS).getCounter();
assertTrue("Expected some records not spilled during reduce" + spill + ")",
spill < 2 * out); // spilled map records, some records at the reduce
}
public void testReduceFromMem() throws Exception {
final int MAP_TASKS = 3;
JobConf job = mrCluster.createJobConf();
job.set("mapred.job.reduce.input.buffer.percent", "1.0");
job.set("mapred.job.shuffle.input.buffer.percent", "1.0");
job.setInt("mapred.job.reduce.total.mem.bytes", 128 << 20);
job.setNumMapTasks(MAP_TASKS);
Counters c = runJob(job);
final long spill = c.findCounter(Task.Counter.SPILLED_RECORDS).getCounter();
final long out = c.findCounter(Task.Counter.MAP_OUTPUT_RECORDS).getCounter();
assertEquals("Spilled records: " + spill, out, spill); // no reduce spill
}
}