/*
* 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.mapred;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
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 java.io.IOException;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
/**
* Used to expire files in cache that hasn't been accessed for a while
*/
public class ExpireUnusedFilesInCache implements Runnable {
/** Logger. */
private static final Log LOG =
LogFactory.getLog(ExpireUnusedFilesInCache.class);
/** Configuration. */
private final Configuration conf;
/** Clock. */
private final Clock clock;
/** The directories to purge. */
private final Path[] cachePath;
/** The filesystem to use. */
private final FileSystem fs;
/** Expire threshold in milliseconds. */
private final long expireCacheThreshold;
/**
* Constructor.
* @param conf The configuration.
* @param clock The clock.
* @param systemDir The system directory.
* @param fs The filesystem.
*/
public ExpireUnusedFilesInCache(
Configuration conf, Clock clock, Path systemDir, FileSystem fs) {
this.conf = conf;
this.clock = clock;
this.fs = fs;
Path sharedPath = new Path(systemDir, JobSubmissionProtocol.CAR);
sharedPath = sharedPath.makeQualified(fs);
this.cachePath = new Path[3];
this.cachePath[0] = new Path(sharedPath, "files");
this.cachePath[1] = new Path(sharedPath, "archives");
this.cachePath[2] = new Path(sharedPath, "libjars");
long clearCacheInterval = conf.getLong(
"mapred.cache.shared.check_interval",
24 * 60 * 60 * 1000);
expireCacheThreshold =
conf.getLong("mapred.cache.shared.expire_threshold",
24 * 60 * 60 * 1000);
Executors.newScheduledThreadPool(1).scheduleAtFixedRate(
this,
clearCacheInterval,
clearCacheInterval,
TimeUnit.MILLISECONDS);
LOG.info("ExpireUnusedFilesInCache created with " +
" sharedPath = " + sharedPath +
" clearCacheInterval = " + clearCacheInterval +
" expireCacheThreshold = " + expireCacheThreshold);
}
@Override
public void run() {
long currentTime = clock.getTime();
for (int i = 0; i < cachePath.length; i++) {
try {
if (!fs.exists(cachePath[i])) continue;
FileStatus[] fStatus = fs.listStatus(cachePath[i]);
for (int j = 0; j < fStatus.length; j++) {
if (!fStatus[j].isDir()) {
long atime = fStatus[j].getAccessTime();
if (currentTime - atime > expireCacheThreshold) {
fs.delete(fStatus[j].getPath(), false);
}
}
}
} catch (IOException ioe) {
LOG.error("IOException when clearing cache");
}
}
}
}