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20 package org.apache.hadoop.hbase.master.snapshot;
21
22 import java.io.IOException;
23 import java.util.LinkedList;
24 import java.util.List;
25 import java.util.concurrent.CancellationException;
26
27 import org.apache.commons.logging.Log;
28 import org.apache.commons.logging.LogFactory;
29 import org.apache.hadoop.classification.InterfaceAudience;
30 import org.apache.hadoop.fs.FileSystem;
31 import org.apache.hadoop.fs.Path;
32 import org.apache.hadoop.hbase.HRegionInfo;
33 import org.apache.hadoop.hbase.HTableDescriptor;
34 import org.apache.hadoop.hbase.catalog.CatalogTracker;
35 import org.apache.hadoop.hbase.catalog.MetaEditor;
36 import org.apache.hadoop.hbase.errorhandling.ForeignException;
37 import org.apache.hadoop.hbase.errorhandling.ForeignExceptionDispatcher;
38 import org.apache.hadoop.hbase.master.AssignmentManager;
39 import org.apache.hadoop.hbase.master.MasterFileSystem;
40 import org.apache.hadoop.hbase.master.MasterServices;
41 import org.apache.hadoop.hbase.master.SnapshotSentinel;
42 import org.apache.hadoop.hbase.master.handler.TableEventHandler;
43 import org.apache.hadoop.hbase.master.metrics.MasterMetrics;
44 import org.apache.hadoop.hbase.monitoring.MonitoredTask;
45 import org.apache.hadoop.hbase.monitoring.TaskMonitor;
46 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
47 import org.apache.hadoop.hbase.snapshot.RestoreSnapshotException;
48 import org.apache.hadoop.hbase.snapshot.RestoreSnapshotHelper;
49 import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
50 import org.apache.hadoop.hbase.util.Bytes;
51
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58 @InterfaceAudience.Private
59 public class RestoreSnapshotHandler extends TableEventHandler implements SnapshotSentinel {
60 private static final Log LOG = LogFactory.getLog(RestoreSnapshotHandler.class);
61
62 private final HTableDescriptor hTableDescriptor;
63 private final SnapshotDescription snapshot;
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65 private final ForeignExceptionDispatcher monitor;
66 private final MasterMetrics metricsMaster;
67 private final MonitoredTask status;
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69 private volatile boolean stopped = false;
70
71 public RestoreSnapshotHandler(final MasterServices masterServices,
72 final SnapshotDescription snapshot, final HTableDescriptor htd,
73 final MasterMetrics metricsMaster) throws IOException {
74 super(EventType.C_M_RESTORE_SNAPSHOT, htd.getName(), masterServices, masterServices);
75 this.metricsMaster = metricsMaster;
76
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78 this.snapshot = snapshot;
79
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81 this.monitor = new ForeignExceptionDispatcher();
82
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84 getTableDescriptor();
85
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87 this.hTableDescriptor = htd;
88
89 this.status = TaskMonitor.get().createStatus(
90 "Restoring snapshot '" + snapshot.getName() + "' to table "
91 + hTableDescriptor.getNameAsString());
92 }
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102 @Override
103 protected void handleTableOperation(List<HRegionInfo> hris) throws IOException {
104 MasterFileSystem fileSystemManager = masterServices.getMasterFileSystem();
105 CatalogTracker catalogTracker = masterServices.getCatalogTracker();
106 FileSystem fs = fileSystemManager.getFileSystem();
107 Path rootDir = fileSystemManager.getRootDir();
108 byte[] tableName = hTableDescriptor.getName();
109 Path tableDir = HTableDescriptor.getTableDir(rootDir, tableName);
110
111 try {
112
113 this.masterServices.getTableDescriptors().add(hTableDescriptor);
114
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116 LOG.debug("Starting restore snapshot=" + SnapshotDescriptionUtils.toString(snapshot));
117 Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshot, rootDir);
118 RestoreSnapshotHelper restoreHelper = new RestoreSnapshotHelper(
119 masterServices.getConfiguration(), fs,
120 snapshot, snapshotDir, hTableDescriptor, tableDir, monitor, status);
121 RestoreSnapshotHelper.RestoreMetaChanges metaChanges = restoreHelper.restoreHdfsRegions();
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130 forceRegionsOffline(metaChanges);
131 forceRegionsOffline(metaChanges);
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142 List<HRegionInfo> hrisToRemove = new LinkedList<HRegionInfo>();
143 if (metaChanges.hasRegionsToRemove()) hrisToRemove.addAll(metaChanges.getRegionsToRemove());
144 MetaEditor.deleteRegions(catalogTracker, hrisToRemove);
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152 hris.clear();
153 if (metaChanges.hasRegionsToAdd()) hris.addAll(metaChanges.getRegionsToAdd());
154 MetaEditor.addRegionsToMeta(catalogTracker, hris);
155 if (metaChanges.hasRegionsToRestore()) {
156 MetaEditor.overwriteRegions(catalogTracker, metaChanges.getRegionsToRestore());
157 }
158 metaChanges.updateMetaParentRegions(catalogTracker, hris);
159
160
161 LOG.info("Restore snapshot=" + SnapshotDescriptionUtils.toString(snapshot) + " on table=" +
162 Bytes.toString(tableName) + " completed!");
163 } catch (IOException e) {
164 String msg = "restore snapshot=" + SnapshotDescriptionUtils.toString(snapshot)
165 + " failed. Try re-running the restore command.";
166 LOG.error(msg, e);
167 monitor.receive(new ForeignException(masterServices.getServerName().toString(), e));
168 throw new RestoreSnapshotException(msg, e);
169 } finally {
170 this.stopped = true;
171 }
172 }
173
174 private void forceRegionsOffline(final RestoreSnapshotHelper.RestoreMetaChanges metaChanges) {
175 forceRegionsOffline(metaChanges.getRegionsToAdd());
176 forceRegionsOffline(metaChanges.getRegionsToRestore());
177 forceRegionsOffline(metaChanges.getRegionsToRemove());
178 }
179
180 private void forceRegionsOffline(final List<HRegionInfo> hris) {
181 AssignmentManager am = this.masterServices.getAssignmentManager();
182 if (hris != null) {
183 for (HRegionInfo hri: hris) {
184 am.regionOffline(hri);
185 }
186 }
187 }
188
189 @Override
190 protected void completed(final Throwable exception) {
191 this.stopped = true;
192 if (exception != null) {
193 status.abort("Restore snapshot '" + snapshot.getName() + "' failed because " +
194 exception.getMessage());
195 } else {
196 status.markComplete("Restore snapshot '"+ snapshot.getName() +"' completed!");
197 }
198 metricsMaster.addSnapshotRestore(status.getCompletionTimestamp() - status.getStartTime());
199 super.completed(exception);
200 }
201
202 @Override
203 public boolean isFinished() {
204 return this.stopped;
205 }
206
207 @Override
208 public long getCompletionTimestamp() {
209 return this.status.getCompletionTimestamp();
210 }
211
212 @Override
213 public SnapshotDescription getSnapshot() {
214 return snapshot;
215 }
216
217 @Override
218 public void cancel(String why) {
219 if (this.stopped) return;
220 this.stopped = true;
221 String msg = "Stopping restore snapshot=" + SnapshotDescriptionUtils.toString(snapshot)
222 + " because: " + why;
223 LOG.info(msg);
224 CancellationException ce = new CancellationException(why);
225 this.monitor.receive(new ForeignException(masterServices.getServerName().toString(), ce));
226 }
227
228 @Override
229 public ForeignException getExceptionIfFailed() {
230 return this.monitor.getException();
231 }
232
233 @Override
234 public void rethrowExceptionIfFailed() throws ForeignException {
235 monitor.rethrowException();
236 }
237 }