/**
* 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.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.BytesWritable;
import org.apache.hadoop.mapred.SortValidator.RecordStatsChecker.NonSplitableSequenceFileInputFormat;
import org.apache.hadoop.mapred.lib.IdentityMapper;
import org.apache.hadoop.mapred.lib.IdentityReducer;
public class TestRackAwareTaskPlacement extends TestCase {
private static final String rack1[] = new String[] {
"/r1"
};
private static final String hosts1[] = new String[] {
"host1.rack1.com"
};
private static final String rack2[] = new String[] {
"/r2", "/r2"
};
private static final String hosts2[] = new String[] {
"host1.rack2.com", "host2.rack2.com"
};
private static final String hosts3[] = new String[] {
"host3.rack1.com"
};
private static final String hosts4[] = new String[] {
"host1.rack2.com"
};
final Path inDir = new Path("/racktesting");
final Path outputPath = new Path("/output");
/**
* Launches a MR job and tests the job counters against the expected values.
* @param testName The name for the job
* @param mr The MR cluster
* @param fileSys The FileSystem
* @param in Input path
* @param out Output path
* @param numMaps Number of maps
* @param otherLocalMaps Expected value of other local maps
* @param datalocalMaps Expected value of data(node) local maps
* @param racklocalMaps Expected value of rack local maps
*/
static void launchJobAndTestCounters(String jobName, MiniMRCluster mr,
FileSystem fileSys, Path in, Path out,
int numMaps, int otherLocalMaps,
int dataLocalMaps, int rackLocalMaps)
throws IOException {
JobConf jobConf = mr.createJobConf();
if (fileSys.exists(out)) {
fileSys.delete(out, true);
}
RunningJob job = launchJob(jobConf, in, out, numMaps, jobName);
Counters counters = job.getCounters();
assertEquals("Number of local maps",
counters.getCounter(JobInProgress.Counter.OTHER_LOCAL_MAPS), otherLocalMaps);
assertEquals("Number of Data-local maps",
counters.getCounter(JobInProgress.Counter.DATA_LOCAL_MAPS),
dataLocalMaps);
assertEquals("Number of Rack-local maps",
counters.getCounter(JobInProgress.Counter.RACK_LOCAL_MAPS),
rackLocalMaps);
mr.waitUntilIdle();
mr.shutdown();
}
public void testTaskPlacement() throws IOException {
String namenode = null;
MiniDFSCluster dfs = null;
MiniMRCluster mr = null;
FileSystem fileSys = null;
String testName = "TestForRackAwareness";
try {
final int taskTrackers = 1;
/* Start 3 datanodes, one in rack r1, and two in r2. Create three
* files (splits).
* 1) file1, just after starting the datanode on r1, with
* a repl factor of 1, and,
* 2) file2 & file3 after starting the other two datanodes, with a repl
* factor of 3.
* At the end, file1 will be present on only datanode1, and, file2 and
* file3, will be present on all datanodes.
*/
Configuration conf = new Configuration();
conf.setBoolean("dfs.replication.considerLoad", false);
dfs = new MiniDFSCluster(conf, 1, true, rack1, hosts1);
dfs.waitActive();
fileSys = dfs.getFileSystem();
if (!fileSys.mkdirs(inDir)) {
throw new IOException("Mkdirs failed to create " + inDir.toString());
}
UtilsForTests.writeFile(dfs.getNameNode(), conf, new Path(inDir + "/file1"), (short)1);
dfs.startDataNodes(conf, 2, true, null, rack2, hosts2, null);
dfs.waitActive();
UtilsForTests.writeFile(dfs.getNameNode(), conf, new Path(inDir + "/file2"), (short)3);
UtilsForTests.writeFile(dfs.getNameNode(), conf, new Path(inDir + "/file3"), (short)3);
namenode = (dfs.getFileSystem()).getUri().getHost() + ":" +
(dfs.getFileSystem()).getUri().getPort();
/* Run a job with the (only)tasktracker on rack2. The rack location
* of the tasktracker will determine how many data/rack local maps it
* runs. The hostname of the tasktracker is set to same as one of the
* datanodes.
*/
mr = new MiniMRCluster(taskTrackers, namenode, 1, rack2, hosts4);
/* The job is configured with three maps since there are three
* (non-splittable) files. On rack2, there are two files and both
* have repl of three. The blocks for those files must therefore be
* present on all the datanodes, in particular, the datanodes on rack2.
* The third input file is pulled from rack1.
*/
launchJobAndTestCounters(testName, mr, fileSys, inDir, outputPath, 3, 0,
2, 0);
mr.shutdown();
/* Run a job with the (only)tasktracker on rack1.
*/
mr = new MiniMRCluster(taskTrackers, namenode, 1, rack1, hosts3);
/* The job is configured with three maps since there are three
* (non-splittable) files. On rack1, because of the way in which repl
* was setup while creating the files, we will have all the three files.
* Thus, a tasktracker will find all inputs in this rack.
*/
launchJobAndTestCounters(testName, mr, fileSys, inDir, outputPath, 3, 0,
0, 3);
mr.shutdown();
} finally {
if (dfs != null) {
dfs.shutdown();
}
if (mr != null) {
mr.shutdown();
}
}
}
static RunningJob launchJob(JobConf jobConf, Path inDir, Path outputPath,
int numMaps, String jobName) throws IOException {
jobConf.setJobName(jobName);
jobConf.setInputFormat(NonSplitableSequenceFileInputFormat.class);
jobConf.setOutputFormat(SequenceFileOutputFormat.class);
FileInputFormat.setInputPaths(jobConf, inDir);
FileOutputFormat.setOutputPath(jobConf, outputPath);
jobConf.setMapperClass(IdentityMapper.class);
jobConf.setReducerClass(IdentityReducer.class);
jobConf.setOutputKeyClass(BytesWritable.class);
jobConf.setOutputValueClass(BytesWritable.class);
jobConf.setNumMapTasks(numMaps);
jobConf.setNumReduceTasks(0);
jobConf.setJar("build/test/testjar/testjob.jar");
return JobClient.runJob(jobConf);
}
}