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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  import java.util.concurrent.ThreadPoolExecutor;
25  
26  import org.apache.commons.logging.Log;
27  import org.apache.commons.logging.LogFactory;
28  import org.apache.hadoop.hbase.HConstants;
29  import org.apache.hadoop.conf.Configuration;
30  import org.apache.hadoop.hbase.HConstants;
31  import org.apache.hadoop.hbase.classification.InterfaceAudience;
32  import org.apache.hadoop.hbase.classification.InterfaceStability;
33  import org.apache.hadoop.hbase.HRegionInfo;
34  import org.apache.hadoop.hbase.ServerName;
35  import org.apache.hadoop.hbase.client.RegionReplicaUtil;
36  import org.apache.hadoop.hbase.errorhandling.ForeignException;
37  import org.apache.hadoop.hbase.master.MasterServices;
38  import org.apache.hadoop.hbase.mob.MobUtils;
39  import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
40  import org.apache.hadoop.hbase.snapshot.ClientSnapshotDescriptionUtils;
41  import org.apache.hadoop.hbase.snapshot.SnapshotManifest;
42  import org.apache.hadoop.hbase.util.Bytes;
43  import org.apache.hadoop.hbase.util.FSUtils;
44  import org.apache.hadoop.hbase.util.ModifyRegionUtils;
45  import org.apache.hadoop.hbase.util.Pair;
46  import org.apache.zookeeper.KeeperException;
47  
48  /**
49   * Take a snapshot of a disabled table.
50   * <p>
51   * Table must exist when taking the snapshot, or results are undefined.
52   */
53  @InterfaceAudience.Private
54  @InterfaceStability.Evolving
55  public class DisabledTableSnapshotHandler extends TakeSnapshotHandler {
56    private static final Log LOG = LogFactory.getLog(DisabledTableSnapshotHandler.class);
57  
58    /**
59     * @param snapshot descriptor of the snapshot to take
60     * @param masterServices master services provider
61     */
62    public DisabledTableSnapshotHandler(SnapshotDescription snapshot,
63        final MasterServices masterServices) {
64      super(snapshot, masterServices);
65    }
66  
67    @Override
68    public DisabledTableSnapshotHandler prepare() throws Exception {
69      return (DisabledTableSnapshotHandler) super.prepare();
70    }
71  
72    // TODO consider parallelizing these operations since they are independent. Right now its just
73    // easier to keep them serial though
74    @Override
75    public void snapshotRegions(List<Pair<HRegionInfo, ServerName>> regionsAndLocations)
76        throws IOException, KeeperException {
77      try {
78        // 1. get all the regions hosting this table.
79  
80        // extract each pair to separate lists
81        Set<HRegionInfo> regions = new HashSet<HRegionInfo>();
82        for (Pair<HRegionInfo, ServerName> p : regionsAndLocations) {
83          // Don't include non-default regions
84          HRegionInfo hri = p.getFirst();
85          if (RegionReplicaUtil.isDefaultReplica(hri)) {
86            regions.add(hri);
87          }
88          // if it's the first region, add the mob region
89          if (Bytes.equals(hri.getStartKey(), HConstants.EMPTY_START_ROW)) {
90            HRegionInfo mobRegion = MobUtils.getMobRegionInfo(hri.getTable());
91            regions.add(mobRegion);
92          }
93        }
94  
95        // 2. for each region, write all the info to disk
96        String msg = "Starting to write region info and WALs for regions for offline snapshot:"
97            + ClientSnapshotDescriptionUtils.toString(snapshot);
98        LOG.info(msg);
99        status.setStatus(msg);
100 
101       ThreadPoolExecutor exec = SnapshotManifest.createExecutor(conf, "DisabledTableSnapshot");
102       try {
103         ModifyRegionUtils.editRegions(exec, regions, new ModifyRegionUtils.RegionEditTask() {
104           @Override
105           public void editRegion(final HRegionInfo regionInfo) throws IOException {
106             snapshotManifest.addRegion(FSUtils.getTableDir(rootDir, snapshotTable), regionInfo);
107           }
108         });
109       } finally {
110         exec.shutdown();
111       }
112     } catch (Exception e) {
113       // make sure we capture the exception to propagate back to the client later
114       String reason = "Failed snapshot " + ClientSnapshotDescriptionUtils.toString(snapshot)
115           + " due to exception:" + e.getMessage();
116       ForeignException ee = new ForeignException(reason, e);
117       monitor.receive(ee);
118       status.abort("Snapshot of table: "+ snapshotTable + " failed because " + e.getMessage());
119     } finally {
120       LOG.debug("Marking snapshot" + ClientSnapshotDescriptionUtils.toString(snapshot)
121           + " as finished.");
122     }
123   }
124 }