org.apache.hadoop.hbase.master.snapshot

Class EnabledTableSnapshotHandler

java.lang.Object

org.apache.hadoop.hbase.executor.EventHandler

org.apache.hadoop.hbase.master.snapshot.TakeSnapshotHandler

org.apache.hadoop.hbase.master.snapshot.EnabledTableSnapshotHandler

All Implemented Interfaces:

Comparable<EventHandler>, Runnable, ForeignExceptionSnare, SnapshotSentinel

@InterfaceAudience.Private
public class EnabledTableSnapshotHandler
extends TakeSnapshotHandler

Handle the master side of taking a snapshot of an online table, regardless of snapshot type. Uses a Procedure to run the snapshot across all the involved region servers.

See Also:

ProcedureCoordinator

Field Summary

Fields

Modifier and Type	Field and Description
private ProcedureCoordinator	coordinator
private static org.slf4j.Logger	LOG

Fields inherited from class org.apache.hadoop.hbase.master.snapshot.TakeSnapshotHandler

conf, htd, master, metricsSnapshot, monitor, rootDir, rootFs, snapshot, snapshotManager, snapshotManifest, snapshotTable, status, workingDir, workingDirFs

Fields inherited from class org.apache.hadoop.hbase.executor.EventHandler

eventType, seqids, server, waitingTimeForEvents

Constructor Summary

Constructors

Constructor and Description
EnabledTableSnapshotHandler(org.apache.hadoop.hbase.shaded.protobuf.generated.SnapshotProtos.SnapshotDescription snapshot, MasterServices master, SnapshotManager manager)

Method Summary

Modifier and Type	Method and Description
protected boolean	downgradeToSharedTableLock() When taking snapshot, first we must acquire the exclusive table lock to confirm that there are no ongoing merge/split procedures.
EnabledTableSnapshotHandler	prepare() Event handlers should do all the necessary checks in this method (rather than in the constructor, or in process()) so that the caller, which is mostly executed in the ipc context can fail fast.
private void	snapshotMobRegion(RegionInfo regionInfo) Takes a snapshot of the mob region
protected void	snapshotRegions(List<Pair<RegionInfo,ServerName>> regions) This method kicks off a snapshot procedure.

Methods inherited from class org.apache.hadoop.hbase.master.snapshot.TakeSnapshotHandler

cancel, getCompletionTimestamp, getException, getExceptionIfFailed, getSnapshot, hasException, isFinished, process, rethrowException, rethrowExceptionIfFailed, snapshotDisabledRegion

Methods inherited from class org.apache.hadoop.hbase.executor.EventHandler

compareTo, getEventType, getInformativeName, getPriority, getSeqid, handleException, run, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

LOG

private static final org.slf4j.Logger LOG

coordinator

private final ProcedureCoordinator coordinator

Constructor Detail

EnabledTableSnapshotHandler

public EnabledTableSnapshotHandler(org.apache.hadoop.hbase.shaded.protobuf.generated.SnapshotProtos.SnapshotDescription snapshot,
                                   MasterServices master,
                                   SnapshotManager manager)
                            throws IOException

Throws:

IOException

Method Detail

prepare

public EnabledTableSnapshotHandler prepare()
                                    throws Exception

Description copied from class: EventHandler

Event handlers should do all the necessary checks in this method (rather than in the constructor, or in process()) so that the caller, which is mostly executed in the ipc context can fail fast. Process is executed async from the client ipc, so this method gives a quick chance to do some basic checks. Should be called after constructing the EventHandler, and before process().

Overrides:

prepare in class TakeSnapshotHandler

Returns:

the instance of this class

Throws:

Exception - when something goes wrong

snapshotRegions

protected void snapshotRegions(List<Pair<RegionInfo,ServerName>> regions)
                        throws IOException

This method kicks off a snapshot procedure. Other than that it hangs around for various phases to complete.

Specified by:

snapshotRegions in class TakeSnapshotHandler

Throws:

IOException

snapshotMobRegion

private void snapshotMobRegion(RegionInfo regionInfo)
                        throws IOException

Takes a snapshot of the mob region

Throws:

IOException

downgradeToSharedTableLock

protected boolean downgradeToSharedTableLock()

Description copied from class: TakeSnapshotHandler

When taking snapshot, first we must acquire the exclusive table lock to confirm that there are no ongoing merge/split procedures. But later, we should try our best to release the exclusive lock as this may hurt the availability, because we need to hold the shared lock when assigning regions.

See HBASE-21480 for more details.

Specified by:

downgradeToSharedTableLock in class TakeSnapshotHandler