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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.hbase.HRegionInfo;
29  import org.apache.hadoop.hbase.ServerName;
30  import org.apache.hadoop.hbase.errorhandling.ForeignException;
31  import org.apache.hadoop.hbase.master.MasterServices;
32  import org.apache.hadoop.hbase.procedure.Procedure;
33  import org.apache.hadoop.hbase.procedure.ProcedureCoordinator;
34  import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
35  import org.apache.hadoop.hbase.snapshot.HBaseSnapshotException;
36  import org.apache.hadoop.hbase.util.Pair;
37  
38  import com.google.common.collect.Lists;
39  
40  /**
41   * Handle the master side of taking a snapshot of an online table, regardless of snapshot type.
42   * Uses a {@link Procedure} to run the snapshot across all the involved region servers.
43   * @see ProcedureCoordinator
44   */
45  @InterfaceAudience.Private
46  public class EnabledTableSnapshotHandler extends TakeSnapshotHandler {
47  
48    private static final Log LOG = LogFactory.getLog(EnabledTableSnapshotHandler.class);
49    private final ProcedureCoordinator coordinator;
50  
51    public EnabledTableSnapshotHandler(SnapshotDescription snapshot, MasterServices master,
52        final SnapshotManager manager) {
53      super(snapshot, master);
54      this.coordinator = manager.getCoordinator();
55    }
56  
57    @Override
58    public EnabledTableSnapshotHandler prepare() throws Exception {
59      return (EnabledTableSnapshotHandler) super.prepare();
60    }
61  
62    // TODO consider switching over to using regionnames, rather than server names. This would allow
63    // regions to migrate during a snapshot, and then be involved when they are ready. Still want to
64    // enforce a snapshot time constraints, but lets us be potentially a bit more robust.
65  
66    /**
67     * This method kicks off a snapshot procedure.  Other than that it hangs around for various
68     * phases to complete.
69     */
70    @Override
71    protected void snapshotRegions(List<Pair<HRegionInfo, ServerName>> regions)
72        throws HBaseSnapshotException, IOException {
73      Set<String> regionServers = new HashSet<String>(regions.size());
74      for (Pair<HRegionInfo, ServerName> region : regions) {
75        if (region != null && region.getFirst() != null && region.getSecond() != null) {
76          HRegionInfo hri = region.getFirst();
77          if (hri.isOffline() && (hri.isSplit() || hri.isSplitParent())) continue;
78          regionServers.add(region.getSecond().toString());
79        }
80      }
81  
82      // start the snapshot on the RS
83      Procedure proc = coordinator.startProcedure(this.monitor, this.snapshot.getName(),
84        this.snapshot.toByteArray(), Lists.newArrayList(regionServers));
85      if (proc == null) {
86        String msg = "Failed to submit distributed procedure for snapshot '"
87            + snapshot.getName() + "'";
88        LOG.error(msg);
89        throw new HBaseSnapshotException(msg);
90      }
91  
92      try {
93        // wait for the snapshot to complete.  A timer thread is kicked off that should cancel this
94        // if it takes too long.
95        proc.waitForCompleted();
96        LOG.info("Done waiting - online snapshot for " + this.snapshot.getName());
97  
98        // Take the offline regions as disabled
99        for (Pair<HRegionInfo, ServerName> region : regions) {
100         HRegionInfo regionInfo = region.getFirst();
101         if (regionInfo.isOffline() && (regionInfo.isSplit() || regionInfo.isSplitParent())) {
102           LOG.info("Take disabled snapshot of offline region=" + regionInfo);
103           snapshotDisabledRegion(regionInfo);
104         }
105       }
106     } catch (InterruptedException e) {
107       ForeignException ee =
108           new ForeignException("Interrupted while waiting for snapshot to finish", e);
109       monitor.receive(ee);
110       Thread.currentThread().interrupt();
111     } catch (ForeignException e) {
112       monitor.receive(e);
113     }
114   }
115 }