// TODO consider parallelizing these operations since they are independent. Right now its just
// easier to keep them serial though
@Override
public void snapshotRegions(List<Pair<HRegionInfo, ServerName>> regionsAndLocations)
throws IOException, KeeperException {
try {
timeoutInjector.start();
// 1. get all the regions hosting this table.
// extract each pair to separate lists
Set<HRegionInfo> regions = new HashSet<HRegionInfo>();
for (Pair<HRegionInfo, ServerName> p : regionsAndLocations) {
regions.add(p.getFirst());
}
// 2. for each region, write all the info to disk
String msg =
"Starting to write region info and WALs for regions for offline snapshot:"
+ ClientSnapshotDescriptionUtils.toString(snapshot);
LOG.info(msg);
status.setStatus(msg);
ThreadPoolExecutor exec = SnapshotManifest.createExecutor(conf, "DisabledTableSnapshot");
try {
ModifyRegionUtils.editRegions(
exec,
regions,
new ModifyRegionUtils.RegionEditTask() {
@Override
public void editRegion(final HRegionInfo regionInfo) throws IOException {
snapshotManifest.addRegion(FSUtils.getTableDir(rootDir, snapshotTable), regionInfo);
}
});
} finally {
exec.shutdown();
}
} catch (Exception e) {
// make sure we capture the exception to propagate back to the client later
String reason =
"Failed snapshot "
+ ClientSnapshotDescriptionUtils.toString(snapshot)
+ " due to exception:"
+ e.getMessage();
ForeignException ee = new ForeignException(reason, e);
monitor.receive(ee);
status.abort("Snapshot of table: " + snapshotTable + " failed because " + e.getMessage());
} finally {
LOG.debug(
"Marking snapshot" + ClientSnapshotDescriptionUtils.toString(snapshot) + " as finished.");
// 3. mark the timer as finished - even if we got an exception, we don't need to time the
// operation any further
timeoutInjector.complete();
}
}
/**
* Clone specified regions. For each region create a new region and create a HFileLink for each
* hfile.
*/
private HRegionInfo[] cloneHdfsRegions(final List<HRegionInfo> regions) throws IOException {
if (regions == null || regions.size() == 0) return null;
final Map<String, HRegionInfo> snapshotRegions =
new HashMap<String, HRegionInfo>(regions.size());
// clone region info (change embedded tableName with the new one)
HRegionInfo[] clonedRegionsInfo = new HRegionInfo[regions.size()];
for (int i = 0; i < clonedRegionsInfo.length; ++i) {
// clone the region info from the snapshot region info
HRegionInfo snapshotRegionInfo = regions.get(i);
clonedRegionsInfo[i] = cloneRegionInfo(snapshotRegionInfo);
// add the region name mapping between snapshot and cloned
String snapshotRegionName = snapshotRegionInfo.getEncodedName();
String clonedRegionName = clonedRegionsInfo[i].getEncodedName();
regionsMap.put(Bytes.toBytes(snapshotRegionName), Bytes.toBytes(clonedRegionName));
LOG.info("clone region=" + snapshotRegionName + " as " + clonedRegionName);
// Add mapping between cloned region name and snapshot region info
snapshotRegions.put(clonedRegionName, snapshotRegionInfo);
}
// create the regions on disk
ModifyRegionUtils.createRegions(
conf,
tableDir.getParent(),
tableDesc,
clonedRegionsInfo,
new ModifyRegionUtils.RegionFillTask() {
public void fillRegion(final HRegion region) throws IOException {
cloneRegion(region, snapshotRegions.get(region.getRegionInfo().getEncodedName()));
}
});
return clonedRegionsInfo;
}
@Override
protected Flow executeFromState(final MasterProcedureEnv env, TruncateTableState state)
throws InterruptedException {
if (LOG.isTraceEnabled()) {
LOG.trace(this + " execute state=" + state);
}
try {
switch (state) {
case TRUNCATE_TABLE_PRE_OPERATION:
// Verify if we can truncate the table
if (!prepareTruncate(env)) {
assert isFailed() : "the truncate should have an exception here";
return Flow.NO_MORE_STATE;
}
// TODO: Move out... in the acquireLock()
LOG.debug("waiting for '" + getTableName() + "' regions in transition");
regions = ProcedureSyncWait.getRegionsFromMeta(env, getTableName());
assert regions != null && !regions.isEmpty() : "unexpected 0 regions";
ProcedureSyncWait.waitRegionInTransition(env, regions);
// Call coprocessors
preTruncate(env);
setNextState(TruncateTableState.TRUNCATE_TABLE_REMOVE_FROM_META);
break;
case TRUNCATE_TABLE_REMOVE_FROM_META:
hTableDescriptor =
env.getMasterServices()
.getTableDescriptors()
.getDescriptor(tableName)
.getHTableDescriptor();
DeleteTableProcedure.deleteFromMeta(env, getTableName(), regions);
DeleteTableProcedure.deleteAssignmentState(env, getTableName());
setNextState(TruncateTableState.TRUNCATE_TABLE_CLEAR_FS_LAYOUT);
break;
case TRUNCATE_TABLE_CLEAR_FS_LAYOUT:
DeleteTableProcedure.deleteFromFs(env, getTableName(), regions, true);
if (!preserveSplits) {
// if we are not preserving splits, generate a new single region
regions = Arrays.asList(ModifyRegionUtils.createHRegionInfos(hTableDescriptor, null));
}
setNextState(TruncateTableState.TRUNCATE_TABLE_CREATE_FS_LAYOUT);
break;
case TRUNCATE_TABLE_CREATE_FS_LAYOUT:
regions = CreateTableProcedure.createFsLayout(env, hTableDescriptor, regions);
CreateTableProcedure.updateTableDescCache(env, getTableName());
setNextState(TruncateTableState.TRUNCATE_TABLE_ADD_TO_META);
break;
case TRUNCATE_TABLE_ADD_TO_META:
regions = CreateTableProcedure.addTableToMeta(env, hTableDescriptor, regions);
setNextState(TruncateTableState.TRUNCATE_TABLE_ASSIGN_REGIONS);
break;
case TRUNCATE_TABLE_ASSIGN_REGIONS:
CreateTableProcedure.assignRegions(env, getTableName(), regions);
setNextState(TruncateTableState.TRUNCATE_TABLE_POST_OPERATION);
hTableDescriptor = null;
regions = null;
break;
case TRUNCATE_TABLE_POST_OPERATION:
postTruncate(env);
LOG.debug("truncate '" + getTableName() + "' completed");
return Flow.NO_MORE_STATE;
default:
throw new UnsupportedOperationException("unhandled state=" + state);
}
} catch (HBaseException | IOException e) {
LOG.warn("Retriable error trying to truncate table=" + getTableName() + " state=" + state, e);
}
return Flow.HAS_MORE_STATE;
}