Package org.apache.hadoop.hbase.regionserver

Class ChunkCreator.MemStoreChunkPool

java.lang.Object

org.apache.hadoop.hbase.regionserver.ChunkCreator.MemStoreChunkPool

All Implemented Interfaces:

HeapMemoryManager.HeapMemoryTuneObserver

Enclosing class:

ChunkCreator

private class ChunkCreator.MemStoreChunkPool
extends Object
implements HeapMemoryManager.HeapMemoryTuneObserver

A pool of Chunk instances. MemStoreChunkPool caches a number of retired chunks for reusing, it could decrease allocating bytes when writing, thereby optimizing the garbage collection on JVM.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private class	ChunkCreator.MemStoreChunkPool.StatisticsThread

Field Summary

Fields

Modifier and Type	Field	Description
private final AtomicLong	chunkCount
private final int	chunkSize
private final ChunkCreator.ChunkType	chunkType
private final String	label
private int	maxCount
private final float	poolSizePercentage
private final BlockingQueue<Chunk>	reclaimedChunks
private final LongAdder	reusedChunkCount
private final ScheduledExecutorService	scheduleThreadPool	Statistics thread schedule pool
private static final int	statThreadPeriod	Statistics thread

Constructor Summary

Constructors

Constructor	Description
MemStoreChunkPool(String label, int chunkSize, ChunkCreator.ChunkType chunkType, int maxCount, int initialCount, float poolSizePercentage)

Method Summary

Modifier and Type	Method	Description
(package private) Chunk	getChunk()	Poll a chunk from the pool, reset it if not null, else create a new chunk to return if we have not yet created max allowed chunks count.
(package private) int	getChunkSize()
private int	getMaxCount()
void	onHeapMemoryTune(long newMemstoreSize, long newBlockCacheSize)	This method would be called by HeapMemoryManger when a heap memory tune action took place.
private void	putbackChunks(Chunk c)	Add the chunks to the pool, when the pool achieves the max size, it will skip the remaining chunks

Methods inherited from class java.lang.Object

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

Field Details

chunkSize

private final int chunkSize

chunkType

private final ChunkCreator.ChunkType chunkType

maxCount

private int maxCount

reclaimedChunks

private final BlockingQueue<Chunk> reclaimedChunks

poolSizePercentage

private final float poolSizePercentage

scheduleThreadPool

private final ScheduledExecutorService scheduleThreadPool

Statistics thread schedule pool

statThreadPeriod

private static final int statThreadPeriod

Statistics thread

See Also:

• Constant Field Values

chunkCount

private final AtomicLong chunkCount

reusedChunkCount

private final LongAdder reusedChunkCount

label

private final String label

Constructor Details

MemStoreChunkPool

MemStoreChunkPool(String label,
 int chunkSize,
 ChunkCreator.ChunkType chunkType,
 int maxCount,
 int initialCount,
 float poolSizePercentage)

Method Details

getChunk

Chunk getChunk()

Poll a chunk from the pool, reset it if not null, else create a new chunk to return if we have not yet created max allowed chunks count. When we have already created max allowed chunks and no free chunks as of now, return null. It is the responsibility of the caller to make a chunk then. Note: Chunks returned by this pool must be put back to the pool after its use.

Returns:

a chunk

See Also:

• putbackChunks(Chunk)

getChunkSize

int getChunkSize()

putbackChunks

private void putbackChunks(Chunk c)

Add the chunks to the pool, when the pool achieves the max size, it will skip the remaining chunks

getMaxCount

private int getMaxCount()

onHeapMemoryTune

public void onHeapMemoryTune(long newMemstoreSize,
 long newBlockCacheSize)

Description copied from interface: HeapMemoryManager.HeapMemoryTuneObserver

This method would be called by HeapMemoryManger when a heap memory tune action took place.

Specified by:

onHeapMemoryTune in interface HeapMemoryManager.HeapMemoryTuneObserver

Parameters:

newMemstoreSize - The newly calculated global memstore size

newBlockCacheSize - The newly calculated global blockcache size