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HBASE-9303 Snapshot restore of table which splits after snapshot was taken encounters 'Region is not online' 

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1517022 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
mbertozzi 2013-08-23 20:30:28 +00:00
parent 819aed4ccd
commit 357fd849bc
1 changed files with 50 additions and 4 deletions
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54
hbase-server/src/main/java/org/apache/hadoop/hbase/master/snapshot/RestoreSnapshotHandler.java
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@ -20,6 +20,7 @@
package org.apache.hadoop.hbase.master.snapshot;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.CancellationException;
@ -36,9 +37,11 @@ import org.apache.hadoop.hbase.catalog.MetaEditor;
import org.apache.hadoop.hbase.errorhandling.ForeignException;
import org.apache.hadoop.hbase.errorhandling.ForeignExceptionDispatcher;
import org.apache.hadoop.hbase.executor.EventType;
import org.apache.hadoop.hbase.master.AssignmentManager;
import org.apache.hadoop.hbase.master.MasterFileSystem;
import org.apache.hadoop.hbase.master.MasterServices;
import org.apache.hadoop.hbase.master.MetricsSnapshot;
import org.apache.hadoop.hbase.master.RegionStates;
import org.apache.hadoop.hbase.master.SnapshotSentinel;
import org.apache.hadoop.hbase.master.handler.TableEventHandler;
import org.apache.hadoop.hbase.monitoring.MonitoredTask;
@ -121,13 +124,40 @@ public class RestoreSnapshotHandler extends TableEventHandler implements Snapsho
snapshot, snapshotDir, hTableDescriptor, rootDir, monitor, status);
RestoreSnapshotHelper.RestoreMetaChanges metaChanges = restoreHelper.restoreHdfsRegions();
// 3. Applies changes to .META.
hris.clear();
// 3. Forces all the RegionStates to be offline
//
// The AssignmentManager keeps all the region states around
// with no possibility to remove them, until the master is restarted.
// This means that a region marked as SPLIT before the restore will never be assigned again.
// To avoid having all states around all the regions are switched to the OFFLINE state,
// which is the same state that the regions will be after a delete table.
forceRegionsOffline(metaChanges);
// 4. Applies changes to .META.
status.setStatus("Preparing to restore each region");
// 4.1 Removes the current set of regions from META
//
// By removing also the regions to restore (the ones present both in the snapshot
// and in the current state) we ensure that no extra fields are present in META
// e.g. with a simple add addRegionToMeta() the splitA and splitB attributes
// not overwritten/removed, so you end up with old informations
// that are not correct after the restore.
List<HRegionInfo> hrisToRemove = new LinkedList<HRegionInfo>();
if (metaChanges.hasRegionsToRemove()) hrisToRemove.addAll(metaChanges.getRegionsToRemove());
if (metaChanges.hasRegionsToRestore()) hrisToRemove.addAll(metaChanges.getRegionsToRestore());
MetaEditor.deleteRegions(catalogTracker, hrisToRemove);
// 4.2 Add the new set of regions to META
//
// At this point the old regions are no longer present in META.
// and the set of regions present in the snapshot will be written to META.
// All the information in META are coming from the .regioninfo of each region present
// in the snapshot folder.
hris.clear();
if (metaChanges.hasRegionsToAdd()) hris.addAll(metaChanges.getRegionsToAdd());
if (metaChanges.hasRegionsToRestore()) hris.addAll(metaChanges.getRegionsToRestore());
List<HRegionInfo> hrisToRemove = metaChanges.getRegionsToRemove();
MetaEditor.mutateRegions(catalogTracker, hrisToRemove, hris);
MetaEditor.addRegionsToMeta(catalogTracker, hris);
metaChanges.updateMetaParentRegions(catalogTracker, hris);
// At this point the restore is complete. Next step is enabling the table.
@ -142,6 +172,22 @@ public class RestoreSnapshotHandler extends TableEventHandler implements Snapsho
}
}
private void forceRegionsOffline(final RestoreSnapshotHelper.RestoreMetaChanges metaChanges) {
forceRegionsOffline(metaChanges.getRegionsToAdd());
forceRegionsOffline(metaChanges.getRegionsToRestore());
forceRegionsOffline(metaChanges.getRegionsToRemove());
}
private void forceRegionsOffline(final List<HRegionInfo> hris) {
AssignmentManager am = this.masterServices.getAssignmentManager();
RegionStates states = am.getRegionStates();
if (hris != null) {
for (HRegionInfo hri: hris) {
states.regionOffline(hri);
}
}
}
@Override
protected void completed(final Throwable exception) {
this.stopped = true;