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1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  package org.apache.hadoop.hbase.master.snapshot;
19  
20  import java.io.IOException;
21  import java.util.Collection;
22  
23  import org.apache.commons.logging.Log;
24  import org.apache.commons.logging.LogFactory;
25  import org.apache.hadoop.classification.InterfaceAudience;
26  import org.apache.hadoop.classification.InterfaceStability;
27  import org.apache.hadoop.conf.Configuration;
28  import org.apache.hadoop.fs.FileStatus;
29  import org.apache.hadoop.fs.FileSystem;
30  import org.apache.hadoop.fs.Path;
31  import org.apache.hadoop.hbase.master.cleaner.BaseHFileCleanerDelegate;
32  import org.apache.hadoop.hbase.snapshot.SnapshotReferenceUtil;
33  import org.apache.hadoop.hbase.util.FSUtils;
34  
35  /**
36   * Implementation of a file cleaner that checks if a hfile is still used by snapshots of HBase
37   * tables.
38   */
39  @InterfaceAudience.Private
40  @InterfaceStability.Evolving
41  public class SnapshotHFileCleaner extends BaseHFileCleanerDelegate {
42    private static final Log LOG = LogFactory.getLog(SnapshotHFileCleaner.class);
43  
44    /**
45     * Conf key for the frequency to attempt to refresh the cache of hfiles currently used in
46     * snapshots (ms)
47     */
48    public static final String HFILE_CACHE_REFRESH_PERIOD_CONF_KEY =
49        "hbase.master.hfilecleaner.plugins.snapshot.period";
50  
51    /** Refresh cache, by default, every 5 minutes */
52    private static final long DEFAULT_HFILE_CACHE_REFRESH_PERIOD = 300000;
53  
54    /** File cache for HFiles in the completed and currently running snapshots */
55    private SnapshotFileCache cache;
56  
57    @Override
58    public synchronized boolean isFileDeletable(FileStatus fStat) {
59      try {
60        return !cache.contains(fStat.getPath().getName());
61      } catch (IOException e) {
62        LOG.error("Exception while checking if:" + fStat.getPath()
63            + " was valid, keeping it just in case.", e);
64        return false;
65      }
66    }
67  
68    @Override
69    public void setConf(Configuration conf) {
70      super.setConf(conf);
71      try {
72        long cacheRefreshPeriod = conf.getLong(HFILE_CACHE_REFRESH_PERIOD_CONF_KEY,
73          DEFAULT_HFILE_CACHE_REFRESH_PERIOD);
74        final FileSystem fs = FSUtils.getCurrentFileSystem(conf);
75        Path rootDir = FSUtils.getRootDir(conf);
76        cache = new SnapshotFileCache(fs, rootDir, cacheRefreshPeriod, cacheRefreshPeriod,
77            "snapshot-hfile-cleaner-cache-refresher", new SnapshotFileCache.SnapshotFileInspector() {
78              public Collection<String> filesUnderSnapshot(final Path snapshotDir)
79                  throws IOException {
80                return SnapshotReferenceUtil.getHFileNames(fs, snapshotDir);
81              }
82            });
83      } catch (IOException e) {
84        LOG.error("Failed to create cleaner util", e);
85      }
86    }
87  
88    @Override
89    public void stop(String why) {
90      this.cache.stop(why);
91    }
92  
93    @Override
94    public boolean isStopped() {
95      return this.cache.isStopped();
96    }
97  
98    /**
99     * Exposed for Testing!
100    * @return the cache of all hfiles
101    */
102   public SnapshotFileCache getFileCacheForTesting() {
103     return this.cache;
104   }
105 }