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* Licensed to the Apache Software Foundation (ASF) under one
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* 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,
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* See the License for the specific language governing permissions and
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package org.apache.hadoop.hdfs.server.namenode;
import junit.framework.TestCase;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.hdfs.DFSTestUtil;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction;
import org.apache.hadoop.hdfs.server.namenode.NNStorage.NameNodeDirType;
import java.util.Collections;
import java.util.List;
import java.io.File;
/**
* A JUnit test for checking if restarting DFS preserves integrity.
* Specifically with FSImage being written in parallel
*/
public class TestParallelImageWrite extends TestCase {
private static final int NUM_DATANODES = 4;
/** check if DFS remains in proper condition after a restart */
public void testRestartDFS() throws Exception {
final Configuration conf = new HdfsConfiguration();
MiniDFSCluster cluster = null;
FSNamesystem fsn = null;
int numNamenodeDirs;
DFSTestUtil files = new DFSTestUtil("TestRestartDFS", 200, 3, 8*1024);
final String dir = "/srcdat";
final Path rootpath = new Path("/");
final Path dirpath = new Path(dir);
long rootmtime;
FileStatus rootstatus;
FileStatus dirstatus;
try {
cluster = new MiniDFSCluster.Builder(conf).format(true)
.numDataNodes(NUM_DATANODES).build();
String[] nameNodeDirs = conf.getStrings(
DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY, new String[] {});
numNamenodeDirs = nameNodeDirs.length;
assertTrue("failed to get number of Namenode StorageDirs",
numNamenodeDirs != 0);
FileSystem fs = cluster.getFileSystem();
files.createFiles(fs, dir);
rootmtime = fs.getFileStatus(rootpath).getModificationTime();
rootstatus = fs.getFileStatus(dirpath);
dirstatus = fs.getFileStatus(dirpath);
fs.setOwner(rootpath, rootstatus.getOwner() + "_XXX", null);
fs.setOwner(dirpath, null, dirstatus.getGroup() + "_XXX");
} finally {
if (cluster != null) { cluster.shutdown(); }
}
try {
// Force the NN to save its images on startup so long as
// there are any uncheckpointed txns
conf.setInt(DFSConfigKeys.DFS_NAMENODE_CHECKPOINT_TXNS_KEY, 1);
// Here we restart the MiniDFScluster without formatting namenode
cluster = new MiniDFSCluster.Builder(conf).format(false)
.numDataNodes(NUM_DATANODES).build();
fsn = cluster.getNamesystem();
FileSystem fs = cluster.getFileSystem();
assertTrue("Filesystem corrupted after restart.",
files.checkFiles(fs, dir));
final FileStatus newrootstatus = fs.getFileStatus(rootpath);
assertEquals(rootmtime, newrootstatus.getModificationTime());
assertEquals(rootstatus.getOwner() + "_XXX", newrootstatus.getOwner());
assertEquals(rootstatus.getGroup(), newrootstatus.getGroup());
final FileStatus newdirstatus = fs.getFileStatus(dirpath);
assertEquals(dirstatus.getOwner(), newdirstatus.getOwner());
assertEquals(dirstatus.getGroup() + "_XXX", newdirstatus.getGroup());
rootmtime = fs.getFileStatus(rootpath).getModificationTime();
final String checkAfterRestart = checkImages(fsn, numNamenodeDirs);
// Modify the system and then perform saveNamespace
files.cleanup(fs, dir);
files.createFiles(fs, dir);
fsn.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
cluster.getNameNodeRpc().saveNamespace();
final String checkAfterModify = checkImages(fsn, numNamenodeDirs);
assertFalse("Modified namespace should change fsimage contents. " +
"was: " + checkAfterRestart + " now: " + checkAfterModify,
checkAfterRestart.equals(checkAfterModify));
fsn.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
files.cleanup(fs, dir);
} finally {
if (cluster != null) { cluster.shutdown(); }
}
}
/**
* Confirm that FSImage files in all StorageDirectory are the same,
* and non-empty, and there are the expected number of them.
* @param fsn - the FSNamesystem being checked.
* @param numImageDirs - the configured number of StorageDirectory of type IMAGE.
* @return - the md5 hash of the most recent FSImage files, which must all be the same.
* @throws AssertionFailedError if image files are empty or different,
* if less than two StorageDirectory are provided, or if the
* actual number of StorageDirectory is less than configured.
*/
public static String checkImages(
FSNamesystem fsn, int numImageDirs)
throws Exception {
NNStorage stg = fsn.getFSImage().getStorage();
//any failed StorageDirectory is removed from the storageDirs list
assertEquals("Some StorageDirectories failed Upgrade",
numImageDirs, stg.getNumStorageDirs(NameNodeDirType.IMAGE));
assertTrue("Not enough fsimage copies in MiniDFSCluster " +
"to test parallel write", numImageDirs > 1);
// List of "current/" directory from each SD
List<File> dirs = FSImageTestUtil.getCurrentDirs(stg, NameNodeDirType.IMAGE);
// across directories, all files with same names should be identical hashes
FSImageTestUtil.assertParallelFilesAreIdentical(
dirs, Collections.<String>emptySet());
FSImageTestUtil.assertSameNewestImage(dirs);
// Return the hash of the newest image file
StorageDirectory firstSd = stg.dirIterator(NameNodeDirType.IMAGE).next();
File latestImage = FSImageTestUtil.findLatestImageFile(firstSd);
String md5 = FSImageTestUtil.getImageFileMD5IgnoringTxId(latestImage);
System.err.println("md5 of " + latestImage + ": " + md5);
return md5;
}
}