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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.conf.Configuration;
29  import org.apache.hadoop.hbase.HConstants;
30  import org.apache.hadoop.hbase.classification.InterfaceAudience;
31  import org.apache.hadoop.hbase.classification.InterfaceStability;
32  import org.apache.hadoop.hbase.HRegionInfo;
33  import org.apache.hadoop.hbase.ServerName;
34  import org.apache.hadoop.hbase.errorhandling.ForeignException;
35  import org.apache.hadoop.hbase.master.MasterServices;
36  import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
37  import org.apache.hadoop.hbase.snapshot.ClientSnapshotDescriptionUtils;
38  import org.apache.hadoop.hbase.snapshot.SnapshotManifest;
39  import org.apache.hadoop.hbase.util.FSUtils;
40  import org.apache.hadoop.hbase.util.ModifyRegionUtils;
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  
54    /**
55     * @param snapshot descriptor of the snapshot to take
56     * @param masterServices master services provider
57     */
58    public DisabledTableSnapshotHandler(SnapshotDescription snapshot,
59        final MasterServices masterServices) {
60      super(snapshot, masterServices);
61    }
62  
63    @Override
64    public DisabledTableSnapshotHandler prepare() throws Exception {
65      return (DisabledTableSnapshotHandler) super.prepare();
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)
72        throws IOException, KeeperException {
73      try {
74        // 1. get all the regions hosting this table.
75  
76        // extract each pair to separate lists
77        Set<HRegionInfo> regions = new HashSet<HRegionInfo>();
78        for (Pair<HRegionInfo, ServerName> p : regionsAndLocations) {
79          regions.add(p.getFirst());
80        }
81  
82        // 2. for each region, write all the info to disk
83        String msg = "Starting to write region info and WALs for regions for offline snapshot:"
84            + ClientSnapshotDescriptionUtils.toString(snapshot);
85        LOG.info(msg);
86        status.setStatus(msg);
87  
88        ThreadPoolExecutor exec = SnapshotManifest.createExecutor(conf, "DisabledTableSnapshot");
89        try {
90          ModifyRegionUtils.editRegions(exec, regions, new ModifyRegionUtils.RegionEditTask() {
91            @Override
92            public void editRegion(final HRegionInfo regionInfo) throws IOException {
93              snapshotManifest.addRegion(FSUtils.getTableDir(rootDir, snapshotTable), regionInfo);
94            }
95          });
96        } finally {
97          exec.shutdown();
98        }
99      } catch (Exception e) {
100       // make sure we capture the exception to propagate back to the client later
101       String reason = "Failed snapshot " + ClientSnapshotDescriptionUtils.toString(snapshot)
102           + " due to exception:" + e.getMessage();
103       ForeignException ee = new ForeignException(reason, e);
104       monitor.receive(ee);
105       status.abort("Snapshot of table: "+ snapshotTable + " failed because " + e.getMessage());
106     } finally {
107       LOG.debug("Marking snapshot" + ClientSnapshotDescriptionUtils.toString(snapshot)
108           + " as finished.");
109     }
110   }
111 }