src/test/org/apache/hadoop/dfs/TestSafeMode.java

/**
 * 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.dfs;

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.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.dfs.FSConstants.SafeModeAction;
import org.apache.hadoop.dfs.NameNode;

import junit.framework.TestCase;

/**
 * This test makes sure that if SafeMode is manually entered, NameNode does not
 * come out of safe mode even after the startup safemode conditions are met.
 */
public class TestSafeMode extends TestCase {
  
  static Log LOG = LogFactory.getLog(TestSafeMode.class);
  
  public void testManualSafeMode() throws IOException {
    MiniDFSCluster cluster = null;
    FileSystem 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 = 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);    
      cluster.shutdown();
      
      // now bring up just the NameNode.
      cluster = new MiniDFSCluster(conf, 0, false, null);
      cluster.waitActive();
      
      LOG.info("Restarted cluster with just the NameNode");
      
      NameNode namenode = cluster.getNameNode();
      
      assertTrue("No datanode is started. Should be in SafeMode", 
                 namenode.isInSafeMode());
      
      // manually set safemode.
      namenode.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.");
      
      try {
        Thread.sleep(2000);
      } catch (InterruptedException ignored) {}
      
      assertTrue("should still be in SafeMode", namenode.isInSafeMode());
      
      namenode.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
      assertFalse("should not be in SafeMode", namenode.isInSafeMode());
    } finally {
      if(fs != null) fs.close();
      if(cluster!= null) cluster.shutdown();
    }
  }
}