org.apache.hadoop.hdfs.server.blockmanagement

Class BlockIdManager

java.lang.Object

org.apache.hadoop.hdfs.server.blockmanagement.BlockIdManager

public class BlockIdManager
extends Object

BlockIdManager allocates the generation stamps and the block ID. The FSNamesystem is responsible for persisting the allocations in the EditLog.

Constructor Summary

Constructors

Constructor and Description
BlockIdManager(org.apache.hadoop.hdfs.server.blockmanagement.BlockManager blockManager)

Method Summary

Methods

Modifier and Type	Method and Description
void	applyImpendingGenerationStamp() Set the current genstamp to the impending genstamp.
long	getGenerationStamp()
long	getGenerationStampAtblockIdSwitch() Gets the value of the generation stamp that delineates sequential and random block IDs.
long	getImpendingGenerationStamp()
long	getLastAllocatedBlockId() Gets the maximum sequentially allocated block ID for this filesystem
long	getLegacyGenerationStamp() Gets the current generation stamp for legacy blocks
long	getLegacyGenerationStampLimit()
void	setGenerationStamp(long stamp) Gets the current generation stamp for this filesystem
void	setGenerationStampIfGreater(long stamp) Set genstamp only when the given one is higher.
void	setImpendingGenerationStamp(long stamp) Set the currently highest gen stamp from active.
void	setLastAllocatedBlockId(long blockId) Sets the maximum allocated block ID for this filesystem.
void	setLegacyGenerationStamp(long stamp) Sets the current generation stamp for legacy blocks
void	setLegacyGenerationStampLimit(long stamp) Sets the generation stamp that delineates random and sequentially allocated block IDs.
long	upgradeLegacyGenerationStamp() Upgrades the generation stamp for the filesystem by reserving a sufficient range for all existing blocks.

Methods inherited from class java.lang.Object

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

Constructor Detail

BlockIdManager

public BlockIdManager(org.apache.hadoop.hdfs.server.blockmanagement.BlockManager blockManager)

Method Detail

upgradeLegacyGenerationStamp

public long upgradeLegacyGenerationStamp()

Upgrades the generation stamp for the filesystem by reserving a sufficient range for all existing blocks. Should be invoked only during the first upgrade to sequential block IDs.

setLegacyGenerationStampLimit

public void setLegacyGenerationStampLimit(long stamp)

Sets the generation stamp that delineates random and sequentially allocated block IDs.

Parameters:

stamp - set generation stamp limit to this value

getGenerationStampAtblockIdSwitch

public long getGenerationStampAtblockIdSwitch()

Gets the value of the generation stamp that delineates sequential and random block IDs.

setLastAllocatedBlockId

public void setLastAllocatedBlockId(long blockId)

Sets the maximum allocated block ID for this filesystem. This is the basis for allocating new block IDs.

getLastAllocatedBlockId

public long getLastAllocatedBlockId()

Gets the maximum sequentially allocated block ID for this filesystem

setLegacyGenerationStamp

public void setLegacyGenerationStamp(long stamp)

Sets the current generation stamp for legacy blocks

getLegacyGenerationStamp

public long getLegacyGenerationStamp()

Gets the current generation stamp for legacy blocks

setGenerationStamp

public void setGenerationStamp(long stamp)

Gets the current generation stamp for this filesystem

setImpendingGenerationStamp

public void setImpendingGenerationStamp(long stamp)

Set the currently highest gen stamp from active. Used by Standby only.

Parameters:

stamp - new genstamp

applyImpendingGenerationStamp

public void applyImpendingGenerationStamp()

Set the current genstamp to the impending genstamp.

getImpendingGenerationStamp

public long getImpendingGenerationStamp()

setGenerationStampIfGreater

public void setGenerationStampIfGreater(long stamp)

Set genstamp only when the given one is higher.

Parameters:

stamp -

getGenerationStamp

public long getGenerationStamp()

getLegacyGenerationStampLimit

public long getLegacyGenerationStampLimit()