/**
* 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 java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.protocol.FSConstants.SafeModeAction;
import org.apache.hadoop.hdfs.DistributedFileSystem;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.hdfs.DFSTestUtil;
import junit.framework.TestCase;
/**
* Tests to verify safe mode correctness.
*/
public class TestSafeMode extends TestCase {
static Log LOG = LogFactory.getLog(TestSafeMode.class);
/**
* This test verifies that if SafeMode is manually entered, name-node does not
* come out of safe mode even after the startup safe mode conditions are met.
* <ol>
* <li>Start cluster with 1 data-node.</li>
* <li>Create 2 files with replication 1.</li>
* <li>Re-start cluster with 0 data-nodes.
* Name-node should stay in automatic safe-mode.</li>
* <li>Enter safe mode manually.</li>
* <li>Start the data-node.</li>
* <li>Wait longer than <tt>dfs.safemode.extension</tt> and
* verify that the name-node is still in safe mode.</li>
* </ol>
*
* @throws IOException
*/
public void testManualSafeMode() throws IOException {
MiniDFSCluster cluster = null;
DistributedFileSystem fs = null;
try {
Configuration conf = new Configuration();
// disable safemode extension to make the test run faster.
conf.set("dfs.safemode.extension", "1");
cluster = new MiniDFSCluster(conf, 1, true, null);
cluster.waitActive();
fs = (DistributedFileSystem)cluster.getFileSystem();
Path file1 = new Path("/tmp/testManualSafeMode/file1");
Path file2 = new Path("/tmp/testManualSafeMode/file2");
LOG.info("Created file1 and file2.");
// create two files with one block each.
DFSTestUtil.createFile(fs, file1, 1000, (short)1, 0);
DFSTestUtil.createFile(fs, file2, 2000, (short)1, 0);
fs.close();
cluster.shutdown();
// now bring up just the NameNode.
cluster = new MiniDFSCluster(conf, 0, false, null);
cluster.waitActive();
fs = (DistributedFileSystem)cluster.getFileSystem();
LOG.info("Restarted cluster with just the NameNode");
assertTrue("No datanode is started. Should be in SafeMode",
fs.setSafeMode(SafeModeAction.SAFEMODE_GET));
// manually set safemode.
fs.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
// now bring up the datanode and wait for it to be active.
cluster.startDataNodes(conf, 1, true, null, null);
cluster.waitActive();
LOG.info("Datanode is started.");
// wait longer than dfs.safemode.extension
try {
Thread.sleep(2000);
} catch (InterruptedException ignored) {}
assertTrue("should still be in SafeMode",
fs.setSafeMode(SafeModeAction.SAFEMODE_GET));
fs.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
assertFalse("should not be in SafeMode",
fs.setSafeMode(SafeModeAction.SAFEMODE_GET));
} finally {
if(fs != null) fs.close();
if(cluster!= null) cluster.shutdown();
}
}
/**
* Verify that the NameNode stays in safemode when dfs.safemode.datanode.min
* is set to a number greater than the number of live datanodes.
*/
public void testDatanodeThreshold() throws IOException {
MiniDFSCluster cluster = null;
DistributedFileSystem fs = null;
try {
Configuration conf = new Configuration();
conf.set("dfs.safemode.extension", "0");
conf.set("dfs.safemode.min.datanodes", "1");
// bring up a cluster with no datanodes
cluster = new MiniDFSCluster(conf, 0, false, null);
cluster.waitActive();
fs = (DistributedFileSystem)cluster.getFileSystem();
assertTrue("No datanode started, but we require one - safemode expected",
fs.setSafeMode(SafeModeAction.SAFEMODE_GET));
String tipMsg = cluster.getNameNode().getNamesystem().getSafeModeTip();
assertTrue("Safemode tip message looks right",
tipMsg.contains("The number of live datanodes 0 needs an " +
"additional 1 live"));
// Start a datanode
cluster.startDataNodes(conf, 1, true, null, null);
// Wait long enough for safemode check to refire
try {
Thread.sleep(1000);
} catch (InterruptedException ignored) {}
// We now should be out of safe mode.
assertFalse(
"Out of safe mode after starting datanode.",
fs.setSafeMode(SafeModeAction.SAFEMODE_GET));
} finally {
if (fs != null) fs.close();
if (cluster != null) cluster.shutdown();
}
}
}