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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.TableName;
35 import org.apache.hadoop.hbase.catalog.CatalogTracker;
36 import org.apache.hadoop.hbase.catalog.MetaEditor;
37 import org.apache.hadoop.hbase.errorhandling.ForeignException;
38 import org.apache.hadoop.hbase.errorhandling.ForeignExceptionDispatcher;
39 import org.apache.hadoop.hbase.executor.EventType;
40 import org.apache.hadoop.hbase.master.AssignmentManager;
41 import org.apache.hadoop.hbase.master.MasterFileSystem;
42 import org.apache.hadoop.hbase.master.MasterServices;
43 import org.apache.hadoop.hbase.master.MetricsSnapshot;
44 import org.apache.hadoop.hbase.master.RegionStates;
45 import org.apache.hadoop.hbase.master.SnapshotSentinel;
46 import org.apache.hadoop.hbase.master.handler.TableEventHandler;
47 import org.apache.hadoop.hbase.monitoring.MonitoredTask;
48 import org.apache.hadoop.hbase.monitoring.TaskMonitor;
49 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
50 import org.apache.hadoop.hbase.snapshot.ClientSnapshotDescriptionUtils;
51 import org.apache.hadoop.hbase.snapshot.RestoreSnapshotException;
52 import org.apache.hadoop.hbase.snapshot.RestoreSnapshotHelper;
53 import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
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61 @InterfaceAudience.Private
62 public class RestoreSnapshotHandler extends TableEventHandler implements SnapshotSentinel {
63 private static final Log LOG = LogFactory.getLog(RestoreSnapshotHandler.class);
64
65 private final HTableDescriptor hTableDescriptor;
66 private final SnapshotDescription snapshot;
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68 private final ForeignExceptionDispatcher monitor;
69 private final MetricsSnapshot metricsSnapshot = new MetricsSnapshot();
70 private final MonitoredTask status;
71
72 private volatile boolean stopped = false;
73
74 public RestoreSnapshotHandler(final MasterServices masterServices,
75 final SnapshotDescription snapshot, final HTableDescriptor htd) throws IOException {
76 super(EventType.C_M_RESTORE_SNAPSHOT, htd.getTableName(), masterServices, masterServices);
77
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79 this.snapshot = snapshot;
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82 this.monitor = new ForeignExceptionDispatcher();
83
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85 getTableDescriptor();
86
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88 this.hTableDescriptor = htd;
89
90 this.status = TaskMonitor.get().createStatus(
91 "Restoring snapshot '" + snapshot.getName() + "' to table "
92 + hTableDescriptor.getTableName());
93 }
94
95 @Override
96 public RestoreSnapshotHandler prepare() throws IOException {
97 return (RestoreSnapshotHandler) super.prepare();
98 }
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108 @Override
109 protected void handleTableOperation(List<HRegionInfo> hris) throws IOException {
110 MasterFileSystem fileSystemManager = masterServices.getMasterFileSystem();
111 CatalogTracker catalogTracker = masterServices.getCatalogTracker();
112 FileSystem fs = fileSystemManager.getFileSystem();
113 Path rootDir = fileSystemManager.getRootDir();
114 TableName tableName = hTableDescriptor.getTableName();
115
116 try {
117
118 this.masterServices.getTableDescriptors().add(hTableDescriptor);
119
120
121 LOG.debug("Starting restore snapshot=" + ClientSnapshotDescriptionUtils.toString(snapshot));
122 Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshot, rootDir);
123 RestoreSnapshotHelper restoreHelper = new RestoreSnapshotHelper(
124 masterServices.getConfiguration(), fs,
125 snapshot, snapshotDir, hTableDescriptor, rootDir, monitor, status);
126 RestoreSnapshotHelper.RestoreMetaChanges metaChanges = restoreHelper.restoreHdfsRegions();
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135 forceRegionsOffline(metaChanges);
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138 status.setStatus("Preparing to restore each region");
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147 List<HRegionInfo> hrisToRemove = new LinkedList<HRegionInfo>();
148 if (metaChanges.hasRegionsToRemove()) hrisToRemove.addAll(metaChanges.getRegionsToRemove());
149 MetaEditor.deleteRegions(catalogTracker, hrisToRemove);
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157 hris.clear();
158 if (metaChanges.hasRegionsToAdd()) hris.addAll(metaChanges.getRegionsToAdd());
159 MetaEditor.addRegionsToMeta(catalogTracker, hris);
160 if (metaChanges.hasRegionsToRestore()) {
161 MetaEditor.overwriteRegions(catalogTracker, metaChanges.getRegionsToRestore());
162 }
163 metaChanges.updateMetaParentRegions(catalogTracker, hris);
164
165
166 LOG.info("Restore snapshot=" + ClientSnapshotDescriptionUtils.toString(snapshot) +
167 " on table=" + tableName + " completed!");
168 } catch (IOException e) {
169 String msg = "restore snapshot=" + ClientSnapshotDescriptionUtils.toString(snapshot)
170 + " failed. Try re-running the restore command.";
171 LOG.error(msg, e);
172 monitor.receive(new ForeignException(masterServices.getServerName().toString(), e));
173 throw new RestoreSnapshotException(msg, e);
174 }
175 }
176
177 private void forceRegionsOffline(final RestoreSnapshotHelper.RestoreMetaChanges metaChanges) {
178 forceRegionsOffline(metaChanges.getRegionsToAdd());
179 forceRegionsOffline(metaChanges.getRegionsToRestore());
180 forceRegionsOffline(metaChanges.getRegionsToRemove());
181 }
182
183 private void forceRegionsOffline(final List<HRegionInfo> hris) {
184 AssignmentManager am = this.masterServices.getAssignmentManager();
185 RegionStates states = am.getRegionStates();
186 if (hris != null) {
187 for (HRegionInfo hri: hris) {
188 states.regionOffline(hri);
189 }
190 }
191 }
192
193 @Override
194 protected void completed(final Throwable exception) {
195 this.stopped = true;
196 if (exception != null) {
197 status.abort("Restore snapshot '" + snapshot.getName() + "' failed because " +
198 exception.getMessage());
199 } else {
200 status.markComplete("Restore snapshot '"+ snapshot.getName() +"'!");
201 }
202 metricsSnapshot.addSnapshotRestore(status.getCompletionTimestamp() - status.getStartTime());
203 super.completed(exception);
204 }
205
206 @Override
207 public boolean isFinished() {
208 return this.stopped;
209 }
210
211 @Override
212 public long getCompletionTimestamp() {
213 return this.status.getCompletionTimestamp();
214 }
215
216 @Override
217 public SnapshotDescription getSnapshot() {
218 return snapshot;
219 }
220
221 @Override
222 public void cancel(String why) {
223 if (this.stopped) return;
224 this.stopped = true;
225 String msg = "Stopping restore snapshot=" + ClientSnapshotDescriptionUtils.toString(snapshot)
226 + " because: " + why;
227 LOG.info(msg);
228 CancellationException ce = new CancellationException(why);
229 this.monitor.receive(new ForeignException(masterServices.getServerName().toString(), ce));
230 }
231
232 @Override
233 public ForeignException getExceptionIfFailed() {
234 return this.monitor.getException();
235 }
236
237 @Override
238 public void rethrowExceptionIfFailed() throws ForeignException {
239 monitor.rethrowException();
240 }
241 }