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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.HashSet;
22  import java.util.List;
23  import java.util.Set;
24  
25  import org.apache.commons.logging.Log;
26  import org.apache.commons.logging.LogFactory;
27  import org.apache.hadoop.classification.InterfaceAudience;
28  import org.apache.hadoop.classification.InterfaceStability;
29  import org.apache.hadoop.fs.Path;
30  import org.apache.hadoop.hbase.HRegionInfo;
31  import org.apache.hadoop.hbase.ServerName;
32  import org.apache.hadoop.hbase.errorhandling.ForeignException;
33  import org.apache.hadoop.hbase.errorhandling.TimeoutExceptionInjector;
34  import org.apache.hadoop.hbase.master.MasterServices;
35  import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
36  import org.apache.hadoop.hbase.regionserver.HRegion;
37  import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
38  import org.apache.hadoop.hbase.snapshot.TableInfoCopyTask;
39  import org.apache.hadoop.hbase.snapshot.TakeSnapshotUtils;
40  import org.apache.hadoop.hbase.util.FSUtils;
41  import org.apache.hadoop.hbase.util.Pair;
42  import org.apache.zookeeper.KeeperException;
43  
44  /**
45   * Take a snapshot of a disabled table.
46   * <p>
47   * Table must exist when taking the snapshot, or results are undefined.
48   */
49  @InterfaceAudience.Private
50  @InterfaceStability.Evolving
51  public class DisabledTableSnapshotHandler extends TakeSnapshotHandler {
52    private static final Log LOG = LogFactory.getLog(DisabledTableSnapshotHandler.class);
53    private final TimeoutExceptionInjector timeoutInjector;
54  
55    /**
56     * @param snapshot descriptor of the snapshot to take
57     * @param masterServices master services provider
58     * @throws IOException on unexpected error
59     */
60    public DisabledTableSnapshotHandler(SnapshotDescription snapshot,
61        final MasterServices masterServices) throws IOException {
62      super(snapshot, masterServices);
63  
64      // setup the timer
65      timeoutInjector = TakeSnapshotUtils.getMasterTimerAndBindToMonitor(snapshot, conf, monitor);
66    }
67  
68    // TODO consider parallelizing these operations since they are independent. Right now its just
69    // easier to keep them serial though
70    @Override
71    public void snapshotRegions(List<Pair<HRegionInfo, ServerName>> regionsAndLocations) throws IOException,
72    KeeperException {
73      try {
74        timeoutInjector.start();
75  
76        // 1. get all the regions hosting this table.
77  
78        // extract each pair to separate lists
79        Set<HRegionInfo> regions = new HashSet<HRegionInfo>();
80        for (Pair<HRegionInfo, ServerName> p : regionsAndLocations) {
81          regions.add(p.getFirst());
82        }
83  
84        // 2. for each region, write all the info to disk
85        LOG.info("Starting to write region info and WALs for regions for offline snapshot:"
86            + SnapshotDescriptionUtils.toString(snapshot));
87        for (HRegionInfo regionInfo : regions) {
88          snapshotDisabledRegion(regionInfo);
89        }
90  
91        // 3. write the table info to disk
92        LOG.info("Starting to copy tableinfo for offline snapshot: " +
93        SnapshotDescriptionUtils.toString(snapshot));
94        TableInfoCopyTask tableInfoCopyTask = new TableInfoCopyTask(this.monitor, snapshot, fs,
95            FSUtils.getRootDir(conf));
96        tableInfoCopyTask.call();
97        monitor.rethrowException();
98      } catch (Exception e) {
99        // make sure we capture the exception to propagate back to the client later
100       String reason = "Failed snapshot " + SnapshotDescriptionUtils.toString(snapshot)
101           + " due to exception:" + e.getMessage();
102       ForeignException ee = new ForeignException(reason, e);
103       monitor.receive(ee);
104     } finally {
105       LOG.debug("Marking snapshot" + SnapshotDescriptionUtils.toString(snapshot)
106           + " as finished.");
107 
108       // 6. mark the timer as finished - even if we got an exception, we don't need to time the
109       // operation any further
110       timeoutInjector.complete();
111     }
112   }
113 }