/**
* 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.lib.chain;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.HadoopTestCase;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.MapReduceTestUtil;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
/**
* Tests error conditions in ChainMapper/ChainReducer.
*/
public class TestChainErrors extends HadoopTestCase {
private static String localPathRoot = System.getProperty("test.build.data",
"/tmp");
public TestChainErrors() throws IOException {
super(HadoopTestCase.LOCAL_MR, HadoopTestCase.LOCAL_FS, 1, 1);
}
private Path inDir = new Path(localPathRoot, "testing/chain/input");
private Path outDir = new Path(localPathRoot, "testing/chain/output");
private String input = "a\nb\nc\nd\n";
/**
* Tests errors during submission.
*
* @throws Exception
*/
public void testChainSubmission() throws Exception {
Configuration conf = createJobConf();
Job job = MapReduceTestUtil.createJob(conf, inDir, outDir, 0, 0, input);
job.setJobName("chain");
Throwable th = null;
// output key,value classes of first map are not same as that of second map
try {
ChainMapper.addMapper(job, Mapper.class, LongWritable.class, Text.class,
IntWritable.class, Text.class, null);
ChainMapper.addMapper(job, Mapper.class, LongWritable.class, Text.class,
LongWritable.class, Text.class, null);
} catch (IllegalArgumentException iae) {
th = iae;
}
assertTrue(th != null);
th = null;
// output key,value classes of reducer are not
// same as that of mapper in the chain
try {
ChainReducer.setReducer(job, Reducer.class, LongWritable.class,
Text.class, IntWritable.class, Text.class, null);
ChainMapper.addMapper(job, Mapper.class, LongWritable.class, Text.class,
LongWritable.class, Text.class, null);
} catch (IllegalArgumentException iae) {
th = iae;
}
assertTrue(th != null);
}
/**
* Tests one of the mappers throwing exception.
*
* @throws Exception
*/
public void testChainFail() throws Exception {
Configuration conf = createJobConf();
Job job = MapReduceTestUtil.createJob(conf, inDir, outDir, 1, 0, input);
job.setJobName("chain");
ChainMapper.addMapper(job, Mapper.class, LongWritable.class, Text.class,
LongWritable.class, Text.class, null);
ChainMapper.addMapper(job, FailMap.class, LongWritable.class, Text.class,
IntWritable.class, Text.class, null);
ChainMapper.addMapper(job, Mapper.class, IntWritable.class, Text.class,
LongWritable.class, Text.class, null);
job.waitForCompletion(true);
assertTrue("Job Not failed", !job.isSuccessful());
}
/**
* Tests Reducer throwing exception.
*
* @throws Exception
*/
public void testReducerFail() throws Exception {
Configuration conf = createJobConf();
Job job = MapReduceTestUtil.createJob(conf, inDir, outDir, 1, 1, input);
job.setJobName("chain");
ChainMapper.addMapper(job, Mapper.class, LongWritable.class, Text.class,
LongWritable.class, Text.class, null);
ChainReducer.setReducer(job, FailReduce.class, LongWritable.class,
Text.class, LongWritable.class, Text.class, null);
ChainReducer.addMapper(job, Mapper.class, LongWritable.class, Text.class,
LongWritable.class, Text.class, null);
job.waitForCompletion(true);
assertTrue("Job Not failed", !job.isSuccessful());
}
/**
* Tests one of the maps consuming output.
*
* @throws Exception
*/
public void testChainMapNoOuptut() throws Exception {
Configuration conf = createJobConf();
String expectedOutput = "";
Job job = MapReduceTestUtil.createJob(conf, inDir, outDir, 1, 0, input);
job.setJobName("chain");
ChainMapper.addMapper(job, ConsumeMap.class, IntWritable.class, Text.class,
LongWritable.class, Text.class, null);
ChainMapper.addMapper(job, Mapper.class, LongWritable.class, Text.class,
LongWritable.class, Text.class, null);
job.waitForCompletion(true);
assertTrue("Job failed", job.isSuccessful());
assertEquals("Outputs doesn't match", expectedOutput, MapReduceTestUtil
.readOutput(outDir, conf));
}
/**
* Tests reducer consuming output.
*
* @throws Exception
*/
public void testChainReduceNoOuptut() throws Exception {
Configuration conf = createJobConf();
String expectedOutput = "";
Job job = MapReduceTestUtil.createJob(conf, inDir, outDir, 1, 1, input);
job.setJobName("chain");
ChainMapper.addMapper(job, Mapper.class, IntWritable.class, Text.class,
LongWritable.class, Text.class, null);
ChainReducer.setReducer(job, ConsumeReduce.class, LongWritable.class,
Text.class, LongWritable.class, Text.class, null);
ChainReducer.addMapper(job, Mapper.class, LongWritable.class, Text.class,
LongWritable.class, Text.class, null);
job.waitForCompletion(true);
assertTrue("Job failed", job.isSuccessful());
assertEquals("Outputs doesn't match", expectedOutput, MapReduceTestUtil
.readOutput(outDir, conf));
}
// this map consumes all the input and output nothing
public static class ConsumeMap extends
Mapper<LongWritable, Text, LongWritable, Text> {
public void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException {
}
}
// this reduce consumes all the input and output nothing
public static class ConsumeReduce extends
Reducer<LongWritable, Text, LongWritable, Text> {
public void reduce(LongWritable key, Iterable<Text> values, Context context)
throws IOException, InterruptedException {
}
}
// this map throws IOException for input value "b"
public static class FailMap extends
Mapper<LongWritable, Text, IntWritable, Text> {
protected void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException {
if (value.toString().equals("b")) {
throw new IOException();
}
}
}
// this reduce throws IOEexception for any input
public static class FailReduce extends
Reducer<LongWritable, Text, LongWritable, Text> {
public void reduce(LongWritable key, Iterable<Text> values, Context context)
throws IOException, InterruptedException {
throw new IOException();
}
}
}