org.apache.hadoop.hdfs.TestFileCreationEmpty.java Source code

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Here is the source code for org.apache.hadoop.hdfs.TestFileCreationEmpty.java

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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;

import java.util.ConcurrentModificationException;
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.server.namenode.LeaseManager;

/**
 * Test empty file creation.
 */
public class TestFileCreationEmpty extends junit.framework.TestCase {
    static final Log LOG = LogFactory.getLog(TestFileCreationEmpty.class);
    private boolean isConcurrentModificationException = false;

    /**
     * This test creates three empty files and lets their leases expire.
     * This triggers release of the leases. 
     * The empty files are supposed to be closed by that 
     * without causing ConcurrentModificationException.
     */
    public void testLeaseExpireEmptyFiles() throws Exception {
        final Thread.UncaughtExceptionHandler oldUEH = Thread.getDefaultUncaughtExceptionHandler();
        Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
            public void uncaughtException(Thread t, Throwable e) {
                if (e instanceof ConcurrentModificationException) {
                    LeaseManager.LOG.error("t=" + t, e);
                    isConcurrentModificationException = true;
                }
            }
        });

        LOG.info("testLeaseExpireEmptyFiles start");
        final long leasePeriod = 1000;
        final int DATANODE_NUM = 3;

        final Configuration conf = new HdfsConfiguration();
        conf.setInt(DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY, 1000);
        conf.setInt(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1);

        // create cluster
        MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).numDataNodes(DATANODE_NUM).build();
        try {
            cluster.waitActive();
            DistributedFileSystem dfs = (DistributedFileSystem) cluster.getFileSystem();

            // create a new file.
            TestFileCreation.createFile(dfs, new Path("/foo"), DATANODE_NUM);
            TestFileCreation.createFile(dfs, new Path("/foo2"), DATANODE_NUM);
            TestFileCreation.createFile(dfs, new Path("/foo3"), DATANODE_NUM);

            // set the soft and hard limit to be 1 second so that the
            // namenode triggers lease recovery
            cluster.setLeasePeriod(leasePeriod, leasePeriod);
            // wait for the lease to expire
            try {
                Thread.sleep(5 * leasePeriod);
            } catch (InterruptedException e) {
            }

            assertFalse(isConcurrentModificationException);
        } finally {
            Thread.setDefaultUncaughtExceptionHandler(oldUEH);
            cluster.shutdown();
        }
    }
}