/**
* 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.mockito.Matchers.anyObject;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.spy;
import java.io.File;
import java.io.IOException;
import junit.framework.TestCase;
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.permission.FsPermission;
import org.apache.hadoop.fs.permission.PermissionStatus;
import org.apache.hadoop.hdfs.protocol.FSConstants.SafeModeAction;
import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory;
import org.apache.hadoop.hdfs.server.namenode.metrics.NameNodeMetrics;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
/**
* Test various failure scenarios during saveNamespace() operation.
* Cases covered:
* <ol>
* <li>Recover from failure while saving into the second storage directory</li>
* <li>Recover from failure while moving current into lastcheckpoint.tmp</li>
* <li>Recover from failure while moving lastcheckpoint.tmp into
* previous.checkpoint</li>
* <li>Recover from failure while rolling edits file</li>
* </ol>
*/
public class TestSaveNamespace extends TestCase {
private static final Log LOG = LogFactory.getLog(TestSaveNamespace.class);
private static class FaultySaveImage implements Answer<Void> {
int count = 0;
FSImage origImage;
public FaultySaveImage(FSImage origImage) {
this.origImage = origImage;
}
public Void answer(InvocationOnMock invocation) throws Exception {
Object[] args = invocation.getArguments();
File f = (File)args[0];
if (count++ == 1) {
LOG.info("Injecting fault for file: " + f);
throw new RuntimeException("Injected fault: saveFSImage second time");
}
LOG.info("Not injecting fault for file: " + f);
origImage.saveFSImage(f);
return null;
}
}
private enum Fault {
SAVE_FSIMAGE,
MOVE_CURRENT,
MOVE_LAST_CHECKPOINT
};
private void saveNamespaceWithInjectedFault(Fault fault) throws IOException {
Configuration conf = getConf();
NameNode.myMetrics = new NameNodeMetrics(conf, null);
NameNode.format(conf);
NameNode nn = new NameNode(conf);
FSNamesystem fsn = nn.getNamesystem();
// Replace the FSImage with a spy
FSImage originalImage = fsn.dir.fsImage;
FSImage spyImage = spy(originalImage);
fsn.dir.fsImage = spyImage;
// inject fault
switch(fault) {
case SAVE_FSIMAGE:
// The spy throws a RuntimeException when writing to the second directory
doAnswer(new FaultySaveImage(originalImage)).
when(spyImage).saveFSImage((File)anyObject());
break;
case MOVE_CURRENT:
// The spy throws a RuntimeException when calling moveCurrent()
doThrow(new RuntimeException("Injected fault: moveCurrent")).
when(spyImage).moveCurrent((StorageDirectory)anyObject());
break;
case MOVE_LAST_CHECKPOINT:
// The spy throws a RuntimeException when calling moveLastCheckpoint()
doThrow(new RuntimeException("Injected fault: moveLastCheckpoint")).
when(spyImage).moveLastCheckpoint((StorageDirectory)anyObject());
break;
}
try {
doAnEdit(fsn, 1);
// Save namespace - this will fail because we inject a fault.
fsn.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
try {
fsn.saveNamespace();
} catch (Exception e) {
LOG.info("Test caught expected exception", e);
}
// Now shut down and restart the namesystem
nn.stop();
nn = null;
// Start a new namesystem, which should be able to recover
// the namespace from the previous incarnation.
nn = new NameNode(conf);
fsn = nn.getNamesystem();
// Make sure the image loaded including our edit.
checkEditExists(fsn, 1);
} finally {
if (nn != null) {
nn.stop();
}
}
}
// @Test
public void testCrashWhileSavingSecondImage() throws Exception {
saveNamespaceWithInjectedFault(Fault.SAVE_FSIMAGE);
}
// @Test
public void testCrashWhileMoveCurrent() throws Exception {
saveNamespaceWithInjectedFault(Fault.MOVE_CURRENT);
}
// @Test
public void testCrashWhileMoveLastCheckpoint() throws Exception {
saveNamespaceWithInjectedFault(Fault.MOVE_LAST_CHECKPOINT);
}
// @Test
public void testSaveWhileEditsRolled() throws Exception {
Configuration conf = getConf();
NameNode.myMetrics = new NameNodeMetrics(conf, null);
NameNode.format(conf);
NameNode nn = new NameNode(conf);
FSNamesystem fsn = nn.getNamesystem();
// Replace the FSImage with a spy
final FSImage originalImage = fsn.dir.fsImage;
FSImage spyImage = spy(originalImage);
fsn.dir.fsImage = spyImage;
try {
doAnEdit(fsn, 1);
CheckpointSignature sig = fsn.rollEditLog();
LOG.warn("Checkpoint signature: " + sig);
// Do another edit
doAnEdit(fsn, 2);
// Save namespace
fsn.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
fsn.saveNamespace();
// Now shut down and restart the NN
nn.stop();
nn = null;
// Start a new namesystem, which should be able to recover
// the namespace from the previous incarnation.
nn = new NameNode(conf);
fsn = nn.getNamesystem();
// Make sure the image loaded including our edits.
checkEditExists(fsn, 1);
checkEditExists(fsn, 2);
} finally {
if (nn != null) {
nn.stop();
}
}
}
private void doAnEdit(FSNamesystem fsn, int id) throws IOException {
// Make an edit
fsn.mkdirs(
"/test" + id,
new PermissionStatus("test", "Test",
new FsPermission((short)0777)));
}
private void checkEditExists(FSNamesystem fsn, int id) throws IOException {
// Make sure the image loaded including our edit.
assertNotNull(fsn.getFileInfo("/test" + id));
}
private Configuration getConf() throws IOException {
String baseDir = System.getProperty("test.build.data", "build/test/data/dfs/");
String nameDirs = baseDir + "name1" + "," + baseDir + "name2";
Configuration conf = new Configuration();
FileSystem.setDefaultUri(conf, "hdfs://localhost:0");
conf.set("dfs.http.address", "0.0.0.0:0");
conf.set("dfs.name.dir", nameDirs);
conf.set("dfs.name.edits.dir", nameDirs);
conf.set("dfs.secondary.http.address", "0.0.0.0:0");
conf.setBoolean("dfs.permissions", false);
return conf;
}
}