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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  import java.util.Collections;
23  
24  import org.apache.commons.logging.Log;
25  import org.apache.commons.logging.LogFactory;
26  import org.apache.hadoop.hbase.classification.InterfaceAudience;
27  import org.apache.hadoop.hbase.classification.InterfaceStability;
28  import org.apache.hadoop.conf.Configuration;
29  import org.apache.hadoop.fs.FileStatus;
30  import org.apache.hadoop.fs.FileSystem;
31  import org.apache.hadoop.fs.Path;
32  import org.apache.hadoop.hbase.HBaseInterfaceAudience;
33  import org.apache.hadoop.hbase.master.cleaner.BaseHFileCleanerDelegate;
34  import org.apache.hadoop.hbase.snapshot.CorruptedSnapshotException;
35  import org.apache.hadoop.hbase.snapshot.SnapshotReferenceUtil;
36  import org.apache.hadoop.hbase.util.FSUtils;
37  
38  /**
39   * Implementation of a file cleaner that checks if a hfile is still used by snapshots of HBase
40   * tables.
41   */
42  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
43  @InterfaceStability.Evolving
44  public class SnapshotHFileCleaner extends BaseHFileCleanerDelegate {
45    private static final Log LOG = LogFactory.getLog(SnapshotHFileCleaner.class);
46  
47    /**
48     * Conf key for the frequency to attempt to refresh the cache of hfiles currently used in
49     * snapshots (ms)
50     */
51    public static final String HFILE_CACHE_REFRESH_PERIOD_CONF_KEY =
52        "hbase.master.hfilecleaner.plugins.snapshot.period";
53  
54    /** Refresh cache, by default, every 5 minutes */
55    private static final long DEFAULT_HFILE_CACHE_REFRESH_PERIOD = 300000;
56  
57    /** File cache for HFiles in the completed and currently running snapshots */
58    private SnapshotFileCache cache;
59  
60    @Override
61    public synchronized Iterable<FileStatus> getDeletableFiles(Iterable<FileStatus> files) {
62      try {
63        return cache.getUnreferencedFiles(files);
64      } catch (CorruptedSnapshotException cse) {
65        LOG.debug("Corrupted in-progress snapshot file exception, ignored ", cse);
66      } catch (IOException e) {
67        LOG.error("Exception while checking if files were valid, keeping them just in case.", e);
68      }
69      return Collections.emptyList();
70    }
71  
72    @Override
73    protected boolean isFileDeletable(FileStatus fStat) {
74      return false;
75    }
76  
77    public void setConf(final Configuration conf) {
78      super.setConf(conf);
79      try {
80        long cacheRefreshPeriod = conf.getLong(HFILE_CACHE_REFRESH_PERIOD_CONF_KEY,
81          DEFAULT_HFILE_CACHE_REFRESH_PERIOD);
82        final FileSystem fs = FSUtils.getCurrentFileSystem(conf);
83        Path rootDir = FSUtils.getRootDir(conf);
84        cache = new SnapshotFileCache(fs, rootDir, cacheRefreshPeriod, cacheRefreshPeriod,
85            "snapshot-hfile-cleaner-cache-refresher", new SnapshotFileCache.SnapshotFileInspector() {
86              public Collection<String> filesUnderSnapshot(final Path snapshotDir)
87                  throws IOException {
88                return SnapshotReferenceUtil.getHFileNames(conf, fs, snapshotDir);
89              }
90            });
91      } catch (IOException e) {
92        LOG.error("Failed to create cleaner util", e);
93      }
94    }
95  
96    @Override
97    public void stop(String why) {
98      this.cache.stop(why);
99    }
100 
101   @Override
102   public boolean isStopped() {
103     return this.cache.isStopped();
104   }
105 
106   /**
107    * Exposed for Testing!
108    * @return the cache of all hfiles
109    */
110   public SnapshotFileCache getFileCacheForTesting() {
111     return this.cache;
112   }
113 }