/**
* 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 junit.framework.TestCase;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.dfs.MiniDFSCluster;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.lib.IdentityMapper;
import org.apache.hadoop.mapred.lib.IdentityReducer;
/**
* A JUnit test to test Map-Reduce empty jobs Mini-DFS.
*/
public class TestEmptyJobWithDFS extends TestCase {
private static final Log LOG =
LogFactory.getLog(TestEmptyJobWithDFS.class.getName());
/**
* Simple method running a MapReduce job with no input data. Used
* to test that such a job is successful.
* @param fileSys
* @param jobTracker
* @param conf
* @param numMaps
* @param numReduces
* @return true if the MR job is successful, otherwise false
* @throws IOException
*/
public static boolean launchEmptyJob(String fileSys,
String jobTracker,
JobConf conf,
int numMaps,
int numReduces) throws IOException {
// create an empty input dir
final Path inDir = new Path("/testing/empty/input");
final Path outDir = new Path("/testing/empty/output");
FileSystem fs = FileSystem.getNamed(fileSys, conf);
fs.delete(outDir);
if (!fs.mkdirs(inDir)) {
LOG.warn("Can't create " + inDir);
return false;
}
// use WordCount example
conf.set("fs.default.name", fileSys);
conf.set("mapred.job.tracker", jobTracker);
conf.setJobName("empty");
// use an InputFormat which returns no split
conf.setInputFormat(EmptyInputFormat.class);
conf.setOutputKeyClass(Text.class);
conf.setOutputValueClass(IntWritable.class);
conf.setMapperClass(IdentityMapper.class);
conf.setReducerClass(IdentityReducer.class);
conf.setInputPath(inDir);
conf.setOutputPath(outDir);
conf.setNumMapTasks(numMaps);
conf.setNumReduceTasks(numReduces);
// run job and wait for completion
JobClient jc = new JobClient(conf);
RunningJob runningJob = jc.submitJob(conf);
while (true) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {}
if (runningJob.isComplete()) {
break;
}
}
try {
assertTrue(runningJob.isComplete());
assertTrue(runningJob.isSuccessful());
} catch (NullPointerException npe) {
// This NPE should no more happens
fail("A NPE should not have happened.");
}
// return job result
LOG.info("job is complete: " + runningJob.isSuccessful());
return (runningJob.isSuccessful());
}
/**
* Test that a job with no input data (and thus with no input split and
* no map task to execute) is successful.
* @throws IOException
*/
public void testEmptyJobWithDFS() throws IOException {
String namenode = null;
MiniDFSCluster dfs = null;
MiniMRCluster mr = null;
FileSystem fileSys = null;
try {
final int taskTrackers = 4;
final int jobTrackerPort = 60050;
Configuration conf = new Configuration();
dfs = new MiniDFSCluster(65315, conf, true);
fileSys = dfs.getFileSystem();
namenode = fileSys.getName();
mr = new MiniMRCluster(jobTrackerPort, 50060, taskTrackers,
namenode, true, 2);
final String jobTrackerName = "localhost:" + mr.getJobTrackerPort();
JobConf jobConf = new JobConf();
boolean result;
result = launchEmptyJob(namenode, jobTrackerName, jobConf,
3, 1);
assertTrue(result);
} finally {
if (fileSys != null) { fileSys.close(); }
if (dfs != null) { dfs.shutdown(); }
if (mr != null) { mr.shutdown(); }
}
}
}