org.apache.hadoop.hdfs.server.namenode.TestNNStorageFailures.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.*;

import java.io.File;
import java.io.IOException;
import java.util.Collection;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
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.junit.After;
import org.junit.Before;
import org.junit.Test;

import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.spy;

public class TestNNStorageFailures {

    public static final Log LOG = LogFactory.getLog(TestNNStorageFailures.class);

    private int editsPerformed = 0;
    private MiniDFSCluster cluster;
    private FileSystem fs;

    @Before
    public void setUpMiniCluster() throws IOException {
        Configuration conf = new Configuration();
        File baseDir = MiniDFSCluster.getBaseDirectory(conf);
        File editDir1 = new File(baseDir, "edit1");
        File editDir2 = new File(baseDir, "edit2");
        conf.set("dfs.name.edits.dir", editDir1.getPath() + "," + editDir2.getPath());

        cluster = new MiniDFSCluster(conf, 0, true, null);
        cluster.waitActive();
        fs = cluster.getFileSystem();
    }

    @After
    public void shutDownMiniCluster() throws IOException {
        if (fs != null)
            fs.close();
        if (cluster != null)
            cluster.shutdown();
    }

    /**
     * Do a mutative metadata operation on the file system.
     * 
     * @return true if the operation was successful, false otherwise.
     */
    private boolean doAnEdit() throws IOException {
        return fs.mkdirs(new Path("/tmp", Integer.toString(editsPerformed++)));
    }

    // check if exception is thrown when all image dirs fail
    @Test
    public void testAllImageDirsFailOnRoll() throws IOException {
        assertTrue(doAnEdit());
        Collection<File> namedirs = cluster.getNameDirs();
        for (File f : namedirs) {
            LOG.info("Changing permissions for directory " + f);
            f.setExecutable(false);
        }
        try {
            cluster.getNameNode().getNamesystem().rollEditLog();
            fail("Should get an exception here");
        } catch (IOException e) {
            LOG.info(e);
            assertTrue(e.toString().contains("No image locations are available"));
            // image dirs are not writable
            assertEquals(2, NameNode.getNameNodeMetrics().imagesFailed.get());
            // journals are separate, and accessible
            assertEquals(0, NameNode.getNameNodeMetrics().journalsFailed.get());
        } finally {
            for (File f : namedirs) {
                LOG.info("Changing permissions for directory " + f);
                f.setExecutable(true);
            }
        }
    }

    // check if image directories are restored at two consecutive SN, 
    // when one fails
    @Test
    public void testImageDirsRemainValidOnInodeMismatch() throws IOException {
        for (int i = 0; i < 10; i++) {
            assertTrue(doAnEdit());
        }

        // replace root dir with a spy
        FSDirectory spyDir = spy(cluster.getNameNode().getNamesystem().dir);
        long originalCount = spyDir.totalInodes();
        cluster.getNameNode().getNamesystem().dir = spyDir;

        doReturn(new Long(originalCount + 1)).when(spyDir).totalInodes();
        // save namespace should fail, but not evict image directories
        try {
            cluster.getNameNode().getNamesystem().saveNamespace(true, false);
            fail("Should get an exception here");
        } catch (IOException e) {
            LOG.info(e);
        }
        doReturn(new Long(originalCount)).when(spyDir).totalInodes();
        cluster.getNameNode().getNamesystem().saveNamespace(true, false);
        assertTrue(cluster.getNameNode().getNamesystem().getFSImage().storage.removedStorageDirs.isEmpty());
        assertEquals(0, NameNode.getNameNodeMetrics().imagesFailed.get());
        assertEquals(0, NameNode.getNameNodeMetrics().journalsFailed.get());
    }
}