org.apache.hadoop.mapred.TestJobSysDirWithDFS.java Source code

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Here is the source code for org.apache.hadoop.mapred.TestJobSysDirWithDFS.java

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/**
 * 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.DataOutputStream;
import java.io.IOException;

import junit.framework.TestCase;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hdfs.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;

/**
 * A JUnit test to test Job System Directory with Mini-DFS.
 */
public class TestJobSysDirWithDFS extends TestCase {
    private static final Log LOG = LogFactory.getLog(TestJobSysDirWithDFS.class.getName());

    static final int NUM_MAPS = 10;
    static final int NUM_SAMPLES = 100000;

    public static class TestResult {
        public String output;
        public RunningJob job;

        TestResult(RunningJob job, String output) {
            this.job = job;
            this.output = output;
        }
    }

    public static TestResult launchWordCount(JobConf conf, Path inDir, Path outDir, String input, int numMaps,
            int numReduces, String sysDir) throws IOException {
        FileSystem inFs = inDir.getFileSystem(conf);
        FileSystem outFs = outDir.getFileSystem(conf);
        outFs.delete(outDir, true);
        if (!inFs.mkdirs(inDir)) {
            throw new IOException("Mkdirs failed to create " + inDir.toString());
        }
        {
            DataOutputStream file = inFs.create(new Path(inDir, "part-0"));
            file.writeBytes(input);
            file.close();
        }
        conf.setJobName("wordcount");
        conf.setInputFormat(TextInputFormat.class);

        // the keys are words (strings)
        conf.setOutputKeyClass(Text.class);
        // the values are counts (ints)
        conf.setOutputValueClass(IntWritable.class);

        conf.setMapperClass(WordCount.MapClass.class);
        conf.setCombinerClass(WordCount.Reduce.class);
        conf.setReducerClass(WordCount.Reduce.class);
        FileInputFormat.setInputPaths(conf, inDir);
        FileOutputFormat.setOutputPath(conf, outDir);
        conf.setNumMapTasks(numMaps);
        conf.setNumReduceTasks(numReduces);
        conf.set("mapred.system.dir", "/tmp/subru/mapred/system");
        JobClient jobClient = new JobClient(conf);
        RunningJob job = jobClient.runJob(conf);
        // Checking that the Job Client system dir is not used
        assertFalse(FileSystem.get(conf).exists(new Path(conf.get("mapred.system.dir"))));
        // Check if the Job Tracker system dir is propogated to client
        sysDir = jobClient.getSystemDir().toString();
        System.out.println("Job sys dir -->" + sysDir);
        assertFalse(sysDir.contains("/tmp/subru/mapred/system"));
        assertTrue(sysDir.contains("custom"));
        return new TestResult(job, TestMiniMRWithDFS.readOutput(outDir, conf));
    }

    static void runWordCount(MiniMRCluster mr, JobConf jobConf, String sysDir) throws IOException {
        LOG.info("runWordCount");
        // Run a word count example
        // Keeping tasks that match this pattern
        TestResult result;
        final Path inDir = new Path("./wc/input");
        final Path outDir = new Path("./wc/output");
        result = launchWordCount(jobConf, inDir, outDir, "The quick brown fox\nhas many silly\n" + "red fox sox\n",
                3, 1, sysDir);
        assertEquals("The\t1\nbrown\t1\nfox\t2\nhas\t1\nmany\t1\n" + "quick\t1\nred\t1\nsilly\t1\nsox\t1\n",
                result.output);
        // Checking if the Job ran successfully in spite of different system dir config
        //  between Job Client & Job Tracker
        assertTrue(result.job.isSuccessful());
    }

    public void testWithDFS() throws IOException {
        MiniDFSCluster dfs = null;
        MiniMRCluster mr = null;
        FileSystem fileSys = null;
        try {
            final int taskTrackers = 4;

            JobConf conf = new JobConf();
            conf.set("mapred.system.dir", "/tmp/custom/mapred/system");
            dfs = new MiniDFSCluster(conf, 4, true, null);
            fileSys = dfs.getFileSystem();
            mr = new MiniMRCluster(taskTrackers, fileSys.getUri().toString(), 1, null, null, conf);

            runWordCount(mr, mr.createJobConf(), conf.get("mapred.system.dir"));
        } finally {
            if (dfs != null) {
                dfs.shutdown();
            }
            if (mr != null) {
                mr.shutdown();
            }
        }
    }

}