org.apache.hadoop.hdfs.server.namenode.TestNameEditsConfigs.java Source code

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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.hdfs.server.namenode;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.Random;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeys;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.hdfs.server.namenode.NNStorage.NameNodeDirType;
import org.apache.hadoop.test.PathUtils;
import org.junit.Before;
import org.junit.Test;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;

/**
 * This class tests various combinations of dfs.namenode.name.dir 
 * and dfs.namenode.edits.dir configurations.
 */
public class TestNameEditsConfigs {

    private static final Log LOG = LogFactory.getLog(FSEditLog.class);

    static final long SEED = 0xDEADBEEFL;
    static final int BLOCK_SIZE = 4096;
    static final int FILE_SIZE = 8192;
    static final int NUM_DATA_NODES = 3;
    static final String FILE_IMAGE = "current/fsimage";
    static final String FILE_EDITS = "current/edits";

    short replication = 3;
    private final File base_dir = new File(PathUtils.getTestDir(TestNameEditsConfigs.class), "dfs");

    @Before
    public void setUp() throws IOException {
        if (base_dir.exists() && !FileUtil.fullyDelete(base_dir)) {
            throw new IOException("Cannot remove directory " + base_dir);
        }
    }

    private void writeFile(FileSystem fileSys, Path name, int repl) throws IOException {
        FSDataOutputStream stm = fileSys.create(name, true,
                fileSys.getConf().getInt(CommonConfigurationKeys.IO_FILE_BUFFER_SIZE_KEY, 4096), (short) repl,
                BLOCK_SIZE);
        byte[] buffer = new byte[FILE_SIZE];
        Random rand = new Random(SEED);
        rand.nextBytes(buffer);
        stm.write(buffer);
        stm.close();
    }

    void checkImageAndEditsFilesExistence(File dir, boolean shouldHaveImages, boolean shouldHaveEdits)
            throws IOException {
        FSImageTransactionalStorageInspector ins = inspect(dir);

        if (shouldHaveImages) {
            assertTrue("Expect images in " + dir, ins.foundImages.size() > 0);
        } else {
            assertTrue("Expect no images in " + dir, ins.foundImages.isEmpty());
        }

        List<FileJournalManager.EditLogFile> editlogs = FileJournalManager
                .matchEditLogs(new File(dir, "current").listFiles());
        if (shouldHaveEdits) {
            assertTrue("Expect edits in " + dir, editlogs.size() > 0);
        } else {
            assertTrue("Expect no edits in " + dir, editlogs.isEmpty());
        }
    }

    private void checkFile(FileSystem fileSys, Path name, int repl) throws IOException {
        assertTrue(fileSys.exists(name));
        int replication = fileSys.getFileStatus(name).getReplication();
        assertEquals("replication for " + name, repl, replication);
        long size = fileSys.getContentSummary(name).getLength();
        assertEquals("file size for " + name, size, FILE_SIZE);
    }

    private void cleanupFile(FileSystem fileSys, Path name) throws IOException {
        assertTrue(fileSys.exists(name));
        fileSys.delete(name, true);
        assertTrue(!fileSys.exists(name));
    }

    SecondaryNameNode startSecondaryNameNode(Configuration conf) throws IOException {
        conf.set(DFSConfigKeys.DFS_NAMENODE_SECONDARY_HTTP_ADDRESS_KEY, "0.0.0.0:0");
        return new SecondaryNameNode(conf);
    }

    /**
     * Test various configuration options of dfs.namenode.name.dir and dfs.namenode.edits.dir
     * The test creates files and restarts cluster with different configs.
     * 1. Starts cluster with shared name and edits dirs
     * 2. Restarts cluster by adding additional (different) name and edits dirs
     * 3. Restarts cluster by removing shared name and edits dirs by allowing to 
     *    start using separate name and edits dirs
     * 4. Restart cluster by adding shared directory again, but make sure we 
     *    do not read any stale image or edits. 
     * All along the test, we create and delete files at reach restart to make
     * sure we are reading proper edits and image.
     * @throws Exception 
     */
    @Test
    public void testNameEditsConfigs() throws Exception {
        Path file1 = new Path("TestNameEditsConfigs1");
        Path file2 = new Path("TestNameEditsConfigs2");
        Path file3 = new Path("TestNameEditsConfigs3");
        MiniDFSCluster cluster = null;
        SecondaryNameNode secondary = null;
        Configuration conf = null;
        FileSystem fileSys = null;
        final File newNameDir = new File(base_dir, "name");
        final File newEditsDir = new File(base_dir, "edits");
        final File nameAndEdits = new File(base_dir, "name_and_edits");
        final File checkpointNameDir = new File(base_dir, "secondname");
        final File checkpointEditsDir = new File(base_dir, "secondedits");
        final File checkpointNameAndEdits = new File(base_dir, "second_name_and_edits");

        ImmutableList<File> allCurrentDirs = ImmutableList.of(new File(nameAndEdits, "current"),
                new File(newNameDir, "current"), new File(newEditsDir, "current"),
                new File(checkpointNameAndEdits, "current"), new File(checkpointNameDir, "current"),
                new File(checkpointEditsDir, "current"));
        ImmutableList<File> imageCurrentDirs = ImmutableList.of(new File(nameAndEdits, "current"),
                new File(newNameDir, "current"), new File(checkpointNameAndEdits, "current"),
                new File(checkpointNameDir, "current"));

        // Start namenode with same dfs.namenode.name.dir and dfs.namenode.edits.dir
        conf = new HdfsConfiguration();
        conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameAndEdits.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, nameAndEdits.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_DIR_KEY, checkpointNameAndEdits.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_EDITS_DIR_KEY, checkpointNameAndEdits.getPath());
        replication = (short) conf.getInt(DFSConfigKeys.DFS_REPLICATION_KEY, 3);
        // Manage our own dfs directories
        cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).manageNameDfsDirs(false).build();

        cluster.waitActive();
        secondary = startSecondaryNameNode(conf);
        fileSys = cluster.getFileSystem();

        try {
            assertTrue(!fileSys.exists(file1));
            writeFile(fileSys, file1, replication);
            checkFile(fileSys, file1, replication);
            secondary.doCheckpoint();
        } finally {
            fileSys.close();
            cluster.shutdown();
            secondary.shutdown();
        }

        // Start namenode with additional dfs.namenode.name.dir and dfs.namenode.edits.dir
        conf = new HdfsConfiguration();
        assertTrue(newNameDir.mkdir());
        assertTrue(newEditsDir.mkdir());

        conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameAndEdits.getPath() + "," + newNameDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, nameAndEdits.getPath() + "," + newEditsDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_DIR_KEY,
                checkpointNameDir.getPath() + "," + checkpointNameAndEdits.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_EDITS_DIR_KEY,
                checkpointEditsDir.getPath() + "," + checkpointNameAndEdits.getPath());
        replication = (short) conf.getInt(DFSConfigKeys.DFS_REPLICATION_KEY, 3);
        // Manage our own dfs directories. Do not format.
        cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).format(false)
                .manageNameDfsDirs(false).build();

        cluster.waitActive();
        secondary = startSecondaryNameNode(conf);
        fileSys = cluster.getFileSystem();

        try {
            assertTrue(fileSys.exists(file1));
            checkFile(fileSys, file1, replication);
            cleanupFile(fileSys, file1);
            writeFile(fileSys, file2, replication);
            checkFile(fileSys, file2, replication);
            secondary.doCheckpoint();
        } finally {
            fileSys.close();
            cluster.shutdown();
            secondary.shutdown();
        }

        FSImageTestUtil.assertParallelFilesAreIdentical(allCurrentDirs, ImmutableSet.of("VERSION"));
        FSImageTestUtil.assertSameNewestImage(imageCurrentDirs);

        // Now remove common directory both have and start namenode with 
        // separate name and edits dirs
        conf = new HdfsConfiguration();
        conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, newNameDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, newEditsDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_DIR_KEY, checkpointNameDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_EDITS_DIR_KEY, checkpointEditsDir.getPath());
        replication = (short) conf.getInt(DFSConfigKeys.DFS_REPLICATION_KEY, 3);
        cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).format(false)
                .manageNameDfsDirs(false).build();

        cluster.waitActive();
        secondary = startSecondaryNameNode(conf);
        fileSys = cluster.getFileSystem();

        try {
            assertTrue(!fileSys.exists(file1));
            assertTrue(fileSys.exists(file2));
            checkFile(fileSys, file2, replication);
            cleanupFile(fileSys, file2);
            writeFile(fileSys, file3, replication);
            checkFile(fileSys, file3, replication);
            secondary.doCheckpoint();
        } finally {
            fileSys.close();
            cluster.shutdown();
            secondary.shutdown();
        }

        // No edit logs in new name dir
        checkImageAndEditsFilesExistence(newNameDir, true, false);
        checkImageAndEditsFilesExistence(newEditsDir, false, true);
        checkImageAndEditsFilesExistence(checkpointNameDir, true, false);
        checkImageAndEditsFilesExistence(checkpointEditsDir, false, true);

        // Add old name_and_edits dir. File system should not read image or edits
        // from old dir
        assertTrue(FileUtil.fullyDelete(new File(nameAndEdits, "current")));
        assertTrue(FileUtil.fullyDelete(new File(checkpointNameAndEdits, "current")));
        conf = new HdfsConfiguration();
        conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameAndEdits.getPath() + "," + newNameDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, nameAndEdits + "," + newEditsDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_DIR_KEY,
                checkpointNameDir.getPath() + "," + checkpointNameAndEdits.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_EDITS_DIR_KEY,
                checkpointEditsDir.getPath() + "," + checkpointNameAndEdits.getPath());
        replication = (short) conf.getInt(DFSConfigKeys.DFS_REPLICATION_KEY, 3);
        cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).format(false)
                .manageNameDfsDirs(false).build();
        cluster.waitActive();
        secondary = startSecondaryNameNode(conf);
        fileSys = cluster.getFileSystem();

        try {
            assertTrue(!fileSys.exists(file1));
            assertTrue(!fileSys.exists(file2));
            assertTrue(fileSys.exists(file3));
            checkFile(fileSys, file3, replication);
            secondary.doCheckpoint();
        } finally {
            fileSys.close();
            cluster.shutdown();
            secondary.shutdown();
        }
        checkImageAndEditsFilesExistence(nameAndEdits, true, true);
        checkImageAndEditsFilesExistence(checkpointNameAndEdits, true, true);
    }

    private FSImageTransactionalStorageInspector inspect(File storageDir) throws IOException {
        return FSImageTestUtil.inspectStorageDirectory(new File(storageDir, "current"),
                NameNodeDirType.IMAGE_AND_EDITS);
    }

    /**
     * Test edits.dir.required configuration options.
     * 1. Directory present in dfs.namenode.edits.dir.required but not in
     *    dfs.namenode.edits.dir. Expected to fail.
     * 2. Directory present in both dfs.namenode.edits.dir.required and
     *    dfs.namenode.edits.dir. Expected to succeed.
     * 3. Directory present only in dfs.namenode.edits.dir. Expected to
     *    succeed.
     */
    @Test
    public void testNameEditsRequiredConfigs() throws IOException {
        MiniDFSCluster cluster = null;
        File nameAndEditsDir = new File(base_dir, "name_and_edits");
        File nameAndEditsDir2 = new File(base_dir, "name_and_edits2");
        File nameDir = new File(base_dir, "name");

        // 1
        // Bad configuration. Add a directory to dfs.namenode.edits.dir.required
        // without adding it to dfs.namenode.edits.dir.
        try {
            Configuration conf = new HdfsConfiguration();
            conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameDir.getAbsolutePath());
            conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_REQUIRED_KEY, nameAndEditsDir2.toURI().toString());
            conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, nameAndEditsDir.toURI().toString());
            cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).manageNameDfsDirs(false)
                    .build();
            fail("Successfully started cluster but should not have been able to.");
        } catch (IllegalArgumentException iae) { // expect to fail
            LOG.info("EXPECTED: cluster start failed due to bad configuration" + iae);
        } finally {
            if (cluster != null) {
                cluster.shutdown();
            }
            cluster = null;
        }

        // 2
        // Good configuration. Add a directory to both dfs.namenode.edits.dir.required
        // and dfs.namenode.edits.dir.
        try {
            Configuration conf = new HdfsConfiguration();
            conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameDir.getAbsolutePath());
            conf.setStrings(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, nameAndEditsDir.toURI().toString(),
                    nameAndEditsDir2.toURI().toString());
            conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_REQUIRED_KEY, nameAndEditsDir2.toURI().toString());
            cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).manageNameDfsDirs(false)
                    .build();
        } finally {
            if (cluster != null) {
                cluster.shutdown();
            }
        }

        // 3
        // Good configuration. Adds a directory to dfs.namenode.edits.dir but not to
        // dfs.namenode.edits.dir.required.
        try {
            Configuration conf = new HdfsConfiguration();
            conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameDir.getAbsolutePath());
            conf.setStrings(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, nameAndEditsDir.toURI().toString(),
                    nameAndEditsDir2.toURI().toString());
            cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).manageNameDfsDirs(false)
                    .build();
        } finally {
            if (cluster != null) {
                cluster.shutdown();
            }
        }
    }

    /**
     * Test various configuration options of dfs.namenode.name.dir and dfs.namenode.edits.dir
     * This test tries to simulate failure scenarios.
     * 1. Start cluster with shared name and edits dir
     * 2. Restart cluster by adding separate name and edits dirs
     * 3. Restart cluster by removing shared name and edits dir
     * 4. Restart cluster with old shared name and edits dir, but only latest 
     *    name dir. This should fail since we don't have latest edits dir
     * 5. Restart cluster with old shared name and edits dir, but only latest
     *    edits dir. This should succeed since the latest edits will have
     *    segments leading all the way from the image in name_and_edits.
     */
    @Test
    public void testNameEditsConfigsFailure() throws IOException {
        Path file1 = new Path("TestNameEditsConfigs1");
        Path file2 = new Path("TestNameEditsConfigs2");
        Path file3 = new Path("TestNameEditsConfigs3");
        MiniDFSCluster cluster = null;
        Configuration conf = null;
        FileSystem fileSys = null;
        File nameOnlyDir = new File(base_dir, "name");
        File editsOnlyDir = new File(base_dir, "edits");
        File nameAndEditsDir = new File(base_dir, "name_and_edits");

        // 1
        // Start namenode with same dfs.namenode.name.dir and dfs.namenode.edits.dir
        conf = new HdfsConfiguration();
        conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameAndEditsDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, nameAndEditsDir.getPath());
        replication = (short) conf.getInt(DFSConfigKeys.DFS_REPLICATION_KEY, 3);

        try {
            // Manage our own dfs directories
            cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).manageNameDfsDirs(false)
                    .build();
            cluster.waitActive();

            // Check that the dir has a VERSION file
            assertTrue(new File(nameAndEditsDir, "current/VERSION").exists());

            fileSys = cluster.getFileSystem();

            assertTrue(!fileSys.exists(file1));
            writeFile(fileSys, file1, replication);
            checkFile(fileSys, file1, replication);
        } finally {
            fileSys.close();
            cluster.shutdown();
        }

        // 2
        // Start namenode with additional dfs.namenode.name.dir and dfs.namenode.edits.dir
        conf = new HdfsConfiguration();
        assertTrue(nameOnlyDir.mkdir());
        assertTrue(editsOnlyDir.mkdir());

        conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameAndEditsDir.getPath() + "," + nameOnlyDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY,
                nameAndEditsDir.getPath() + "," + editsOnlyDir.getPath());
        replication = (short) conf.getInt(DFSConfigKeys.DFS_REPLICATION_KEY, 3);

        try {
            // Manage our own dfs directories. Do not format.
            cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).format(false)
                    .manageNameDfsDirs(false).build();
            cluster.waitActive();

            // Check that the dirs have a VERSION file
            assertTrue(new File(nameAndEditsDir, "current/VERSION").exists());
            assertTrue(new File(nameOnlyDir, "current/VERSION").exists());
            assertTrue(new File(editsOnlyDir, "current/VERSION").exists());

            fileSys = cluster.getFileSystem();

            assertTrue(fileSys.exists(file1));
            checkFile(fileSys, file1, replication);
            cleanupFile(fileSys, file1);
            writeFile(fileSys, file2, replication);
            checkFile(fileSys, file2, replication);
        } finally {
            fileSys.close();
            cluster.shutdown();
        }

        // 3
        // Now remove common directory both have and start namenode with 
        // separate name and edits dirs
        try {
            conf = new HdfsConfiguration();
            conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameOnlyDir.getPath());
            conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, editsOnlyDir.getPath());
            replication = (short) conf.getInt(DFSConfigKeys.DFS_REPLICATION_KEY, 3);
            cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).format(false)
                    .manageNameDfsDirs(false).build();
            cluster.waitActive();
            fileSys = cluster.getFileSystem();

            assertFalse(fileSys.exists(file1));
            assertTrue(fileSys.exists(file2));
            checkFile(fileSys, file2, replication);
            cleanupFile(fileSys, file2);
            writeFile(fileSys, file3, replication);
            checkFile(fileSys, file3, replication);
        } finally {
            fileSys.close();
            cluster.shutdown();
        }

        // 4
        // Add old shared directory for name and edits along with latest name
        conf = new HdfsConfiguration();
        conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameOnlyDir.getPath() + "," + nameAndEditsDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY, nameAndEditsDir.getPath());
        replication = (short) conf.getInt(DFSConfigKeys.DFS_REPLICATION_KEY, 3);
        try {
            cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).format(false)
                    .manageNameDfsDirs(false).build();
            fail("Successfully started cluster but should not have been able to.");
        } catch (IOException e) { // expect to fail
            LOG.info("EXPECTED: cluster start failed due to missing " + "latest edits dir", e);
        } finally {
            if (cluster != null) {
                cluster.shutdown();
            }
            cluster = null;
        }

        // 5
        // Add old shared directory for name and edits along with latest edits. 
        // This is OK, since the latest edits will have segments leading all
        // the way from the image in name_and_edits.
        conf = new HdfsConfiguration();
        conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameAndEditsDir.getPath());
        conf.set(DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY,
                editsOnlyDir.getPath() + "," + nameAndEditsDir.getPath());
        replication = (short) conf.getInt(DFSConfigKeys.DFS_REPLICATION_KEY, 3);
        try {
            cluster = new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATA_NODES).format(false)
                    .manageNameDfsDirs(false).build();

            fileSys = cluster.getFileSystem();

            assertFalse(fileSys.exists(file1));
            assertFalse(fileSys.exists(file2));
            assertTrue(fileSys.exists(file3));
            checkFile(fileSys, file3, replication);
            cleanupFile(fileSys, file3);
            writeFile(fileSys, file3, replication);
            checkFile(fileSys, file3, replication);
        } finally {
            fileSys.close();
            cluster.shutdown();
        }
    }

    /**
     * Test dfs.namenode.checkpoint.dir and dfs.namenode.checkpoint.edits.dir
     * should tolerate white space between values.
     */
    @Test
    public void testCheckPointDirsAreTrimmed() throws Exception {
        MiniDFSCluster cluster = null;
        SecondaryNameNode secondary = null;
        File checkpointNameDir1 = new File(base_dir, "chkptName1");
        File checkpointEditsDir1 = new File(base_dir, "chkptEdits1");
        File checkpointNameDir2 = new File(base_dir, "chkptName2");
        File checkpointEditsDir2 = new File(base_dir, "chkptEdits2");
        File nameDir = new File(base_dir, "name1");
        String whiteSpace = "  \n   \n  ";
        Configuration conf = new HdfsConfiguration();
        conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, nameDir.getPath());
        conf.setStrings(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_DIR_KEY,
                whiteSpace + checkpointNameDir1.getPath() + whiteSpace,
                whiteSpace + checkpointNameDir2.getPath() + whiteSpace);
        conf.setStrings(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_EDITS_DIR_KEY,
                whiteSpace + checkpointEditsDir1.getPath() + whiteSpace,
                whiteSpace + checkpointEditsDir2.getPath() + whiteSpace);
        cluster = new MiniDFSCluster.Builder(conf).manageNameDfsDirs(false).numDataNodes(3).build();
        try {
            cluster.waitActive();
            secondary = startSecondaryNameNode(conf);
            secondary.doCheckpoint();
            assertTrue(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY + " must be trimmed ", checkpointNameDir1.exists());
            assertTrue(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY + " must be trimmed ", checkpointNameDir2.exists());
            assertTrue(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_EDITS_DIR_KEY + " must be trimmed ",
                    checkpointEditsDir1.exists());
            assertTrue(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_EDITS_DIR_KEY + " must be trimmed ",
                    checkpointEditsDir2.exists());
        } finally {
            secondary.shutdown();
            cluster.shutdown();
        }
    }
}