Package org.apache.hadoop.hdfs.server.namenode.ha

Class StandbyCheckpointer

java.lang.Object

org.apache.hadoop.hdfs.server.namenode.ha.StandbyCheckpointer

@Private
public class StandbyCheckpointer
extends Object

Thread which runs inside the NN when it's in Standby state, periodically waking up to take a checkpoint of the namespace. When it takes a checkpoint, it saves it to its local storage and then uploads it to the remote NameNode.

Constructor Summary

Constructors

Constructor	Description
StandbyCheckpointer(org.apache.hadoop.conf.Configuration conf, FSNamesystem ns)

Method Summary

Modifier and Type	Method	Description
void	cancelAndPreventCheckpoints(String msg)	Cancel any checkpoint that's currently being made, and prevent any new checkpoints from starting for the next minute or so.
long	getLastCheckpointTime()
void	start()
void	stop()
void	triggerRollbackCheckpoint()

Methods inherited from class java.lang.Object

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

Constructor Details

StandbyCheckpointer

public StandbyCheckpointer(org.apache.hadoop.conf.Configuration conf,
 FSNamesystem ns)
                    throws IOException

Throws:

IOException

Method Details

start

public void start()

stop

public void stop()
          throws IOException

Throws:

IOException

triggerRollbackCheckpoint

public void triggerRollbackCheckpoint()

cancelAndPreventCheckpoints

public void cancelAndPreventCheckpoints(String msg)
                                 throws org.apache.hadoop.ha.ServiceFailedException

Cancel any checkpoint that's currently being made, and prevent any new checkpoints from starting for the next minute or so.

Throws:

org.apache.hadoop.ha.ServiceFailedException

getLastCheckpointTime

@VisibleForTesting
public long getLastCheckpointTime()