org.apache.hadoop.hbase.master.snapshot

Class SnapshotManager

java.lang.Object

org.apache.hadoop.hbase.master.snapshot.SnapshotManager

All Implemented Interfaces:

Stoppable

@InterfaceAudience.Private
@InterfaceStability.Unstable
public class SnapshotManager
extends Object
implements Stoppable

This class manages the procedure of taking and restoring snapshots. There is only one SnapshotManager for the master.

The class provides methods for monitoring in-progress snapshot actions.

Note: Currently there can only be one snapshot being taken at a time over the cluster. This is a simplification in the current implementation.

Field Summary

Fields

Modifier and Type	Field and Description
static String	HBASE_SNAPSHOT_ENABLED Enable or disable snapshot support
static String	ONLINE_SNAPSHOT_CONTROLLER_DESCRIPTION Name of the operation to use in the controller

Constructor Summary

Constructors

Constructor and Description
SnapshotManager(MasterServices master, MetricsMaster metricsMaster) Construct a snapshot manager.
SnapshotManager(MasterServices master, MetricsMaster metricsMaster, ProcedureCoordinator coordinator, ExecutorService pool) Fully specify all necessary components of a snapshot manager.

Method Summary

Methods

Modifier and Type	Method and Description
void	checkSnapshotSupport() Throws an exception if snapshot operations (take a snapshot, restore, clone) are not supported.
void	deleteSnapshot(HBaseProtos.SnapshotDescription snapshot) Delete the specified snapshot
List<HBaseProtos.SnapshotDescription>	getCompletedSnapshots() Gets the list of all completed snapshots.
boolean	isRestoreDone(HBaseProtos.SnapshotDescription snapshot) Returns the status of a restore operation.
boolean	isSnapshotDone(HBaseProtos.SnapshotDescription expected) Check if the specified snapshot is done
boolean	isStopped()
void	restoreSnapshot(HBaseProtos.SnapshotDescription reqSnapshot) Restore the specified snapshot
void	setSnapshotHandlerForTesting(TableName tableName, SnapshotSentinel handler) Set the handler for the current snapshot
void	stop(String why)
void	takeSnapshot(HBaseProtos.SnapshotDescription snapshot) Take a snapshot based on the enabled/disabled state of the table.

Methods inherited from class java.lang.Object

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

Field Detail

HBASE_SNAPSHOT_ENABLED

public static final String HBASE_SNAPSHOT_ENABLED

Enable or disable snapshot support

See Also:

Constant Field Values

ONLINE_SNAPSHOT_CONTROLLER_DESCRIPTION

public static final String ONLINE_SNAPSHOT_CONTROLLER_DESCRIPTION

Name of the operation to use in the controller

See Also:

Constant Field Values

Constructor Detail

SnapshotManager

public SnapshotManager(MasterServices master,
               MetricsMaster metricsMaster)
                throws org.apache.zookeeper.KeeperException,
                       IOException,
                       UnsupportedOperationException

Construct a snapshot manager.

Parameters:

master -

Throws:

org.apache.zookeeper.KeeperException

IOException

UnsupportedOperationException

SnapshotManager

public SnapshotManager(MasterServices master,
               MetricsMaster metricsMaster,
               ProcedureCoordinator coordinator,
               ExecutorService pool)
                throws IOException,
                       UnsupportedOperationException

Fully specify all necessary components of a snapshot manager. Exposed for testing.

Parameters:

master - services for the master where the manager is running

coordinator - procedure coordinator instance. exposed for testing.

pool - HBase ExecutorServcie instance, exposed for testing.

Throws:

IOException

UnsupportedOperationException

Method Detail

getCompletedSnapshots

public List<HBaseProtos.SnapshotDescription> getCompletedSnapshots()
                                                            throws IOException

Gets the list of all completed snapshots.

Returns:

list of SnapshotDescriptions

Throws:

IOException - File system exception

deleteSnapshot

public void deleteSnapshot(HBaseProtos.SnapshotDescription snapshot)
                    throws SnapshotDoesNotExistException,
                           IOException

Delete the specified snapshot

Parameters:

snapshot -

Throws:

SnapshotDoesNotExistException - If the specified snapshot does not exist.

IOException - For filesystem IOExceptions

isSnapshotDone

public boolean isSnapshotDone(HBaseProtos.SnapshotDescription expected)
                       throws IOException

Check if the specified snapshot is done

Parameters:

expected -

Returns:

true if snapshot is ready to be restored, false if it is still being taken.

Throws:

IOException - IOException if error from HDFS or RPC

UnknownSnapshotException - if snapshot is invalid or does not exist.

takeSnapshot

public void takeSnapshot(HBaseProtos.SnapshotDescription snapshot)
                  throws IOException

Take a snapshot based on the enabled/disabled state of the table.

Parameters:

snapshot -

Throws:

HBaseSnapshotException - when a snapshot specific exception occurs.

IOException - when some sort of generic IO exception occurs.

setSnapshotHandlerForTesting

public void setSnapshotHandlerForTesting(TableName tableName,
                                SnapshotSentinel handler)

Set the handler for the current snapshot

Exposed for TESTING

Parameters:

tableName -

handler - handler the master should use TODO get rid of this if possible, repackaging, modify tests.

restoreSnapshot

public void restoreSnapshot(HBaseProtos.SnapshotDescription reqSnapshot)
                     throws IOException

Restore the specified snapshot

Parameters:

reqSnapshot -

Throws:

IOException

isRestoreDone

public boolean isRestoreDone(HBaseProtos.SnapshotDescription snapshot)
                      throws IOException

Returns the status of a restore operation. If the in-progress restore is failed throws the exception that caused the failure.

Parameters:

snapshot -

Returns:

false if in progress, true if restore is completed or not requested.

Throws:

IOException - if there was a failure during the restore

stop

public void stop(String why)

Specified by:

stop in interface Stoppable

isStopped

public boolean isStopped()

Specified by:

isStopped in interface Stoppable

checkSnapshotSupport

public void checkSnapshotSupport()
                          throws UnsupportedOperationException

Throws an exception if snapshot operations (take a snapshot, restore, clone) are not supported. Called at the beginning of snapshot() and restoreSnapshot() methods.

Throws:

UnsupportedOperationException - if snapshot are not supported