org.apache.hadoop.hbase.regionserver

Class MemStoreCompactor

java.lang.Object

org.apache.hadoop.hbase.regionserver.MemStoreCompactor

@InterfaceAudience.Private
public class MemStoreCompactor
extends Object

The ongoing MemStore Compaction manager, dispatches a solo running compaction and interrupts the compaction if requested. The compaction is interrupted and stopped by CompactingMemStore, for example when another compaction needs to be started. Prior to compaction the MemStoreCompactor evaluates the compacting ratio and aborts the compaction if it is not worthy. The MemStoreScanner is used to traverse the compaction pipeline. The MemStoreScanner is included in internal store scanner, where all compaction logic is implemented. Threads safety: It is assumed that the compaction pipeline is immutable, therefore no special synchronization is required.

Field Summary

Fields

Modifier and Type	Field and Description
private CompactingMemStore	compactingMemStore
private int	compactionKVMax
static long	DEEP_OVERHEAD
private AtomicBoolean	isInterrupted
private static org.slf4j.Logger	LOG
private MemStoreCompactionStrategy	strategy
private VersionedSegmentsList	versionedList

Constructor Summary

Constructors

Constructor and Description
MemStoreCompactor(CompactingMemStore compactingMemStore, MemoryCompactionPolicy compactionPolicy)

Method Summary

Modifier and Type	Method and Description
private ImmutableSegment	createSubstitution(MemStoreCompactionStrategy.Action action) ---------------------------------------------------------------------- Creation of the ImmutableSegment either by merge or copy-compact of the segments of the pipeline, based on the Compactor Iterator.
private void	doCompaction() ---------------------------------------------------------------------- The worker thread performs the compaction asynchronously.
(package private) void	initiateCompactionStrategy(MemoryCompactionPolicy compType, org.apache.hadoop.conf.Configuration configuration, String cfName)
private void	releaseResources() ---------------------------------------------------------------------- Reset the interruption indicator and clear the pointers in order to allow good garbage collection
void	resetStats()
boolean	start() ---------------------------------------------------------------------- The request to dispatch the compaction asynchronous task.
void	stop() ---------------------------------------------------------------------- The request to cancel the compaction asynchronous task The compaction may still happen if the request was sent too late Non-blocking request
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

DEEP_OVERHEAD

public static final long DEEP_OVERHEAD

LOG

private static final org.slf4j.Logger LOG

compactingMemStore

private CompactingMemStore compactingMemStore

versionedList

private VersionedSegmentsList versionedList

isInterrupted

private final AtomicBoolean isInterrupted

compactionKVMax

private final int compactionKVMax

strategy

private MemStoreCompactionStrategy strategy

Constructor Detail

MemStoreCompactor

public MemStoreCompactor(CompactingMemStore compactingMemStore,
                         MemoryCompactionPolicy compactionPolicy)
                  throws IllegalArgumentIOException

Throws:

IllegalArgumentIOException

Method Detail

toString

public String toString()

Overrides:

toString in class Object

start

public boolean start()
              throws IOException

---------------------------------------------------------------------- The request to dispatch the compaction asynchronous task. The method returns true if compaction was successfully dispatched, or false if there is already an ongoing compaction or no segments to compact.

Throws:

IOException

stop

public void stop()

---------------------------------------------------------------------- The request to cancel the compaction asynchronous task The compaction may still happen if the request was sent too late Non-blocking request

resetStats

public void resetStats()

releaseResources

private void releaseResources()

---------------------------------------------------------------------- Reset the interruption indicator and clear the pointers in order to allow good garbage collection

doCompaction

private void doCompaction()

---------------------------------------------------------------------- The worker thread performs the compaction asynchronously. The solo (per compactor) thread only reads the compaction pipeline. There is at most one thread per memstore instance.

createSubstitution

private ImmutableSegment createSubstitution(MemStoreCompactionStrategy.Action action)
                                     throws IOException

---------------------------------------------------------------------- Creation of the ImmutableSegment either by merge or copy-compact of the segments of the pipeline, based on the Compactor Iterator. The new ImmutableSegment is returned.

Throws:

IOException

initiateCompactionStrategy

void initiateCompactionStrategy(MemoryCompactionPolicy compType,
                                org.apache.hadoop.conf.Configuration configuration,
                                String cfName)
                         throws IllegalArgumentIOException

Throws:

IllegalArgumentIOException