org.apache.cassandra.db.compaction
Class LeveledCompactionStrategy

java.lang.Object
  org.apache.cassandra.db.compaction.AbstractCompactionStrategy
      org.apache.cassandra.db.compaction.LeveledCompactionStrategy

All Implemented Interfaces:

INotificationConsumer

public class LeveledCompactionStrategy
extends AbstractCompactionStrategy
implements INotificationConsumer

Field Summary

Fields inherited from class org.apache.cassandra.db.compaction.AbstractCompactionStrategy

cfs, options

Constructor Summary

LeveledCompactionStrategy(ColumnFamilyStore cfs, java.util.Map<java.lang.String,java.lang.String> options)

Method Summary

int	getEstimatedRemainingTasks()
int	getLevelSize(int i)
AbstractCompactionTask	getMaximalTask(int gcBefore)
long	getMaxSSTableSize()
AbstractCompactionTask	getNextBackgroundTask(int gcBefore) the only difference between background and maximal in LCS is that maximal is still allowed (by explicit user request) even when compaction is disabled.
java.util.List<ICompactionScanner>	getScanners(java.util.Collection<SSTableReader> sstables, Range<Token> range) Returns a list of KeyScanners given sstables and a range on which to scan.
AbstractCompactionTask	getUserDefinedTask(java.util.Collection<SSTableReader> sstables, int gcBefore)
void	handleNotification(INotification notification, java.lang.Object sender)
boolean	isKeyExistenceExpensive(java.util.Set<? extends SSTable> sstablesToIgnore)
void	shutdown() Releases any resources if this strategy is shutdown (when the CFS is reloaded after a schema change).
java.lang.String	toString()

Methods inherited from class org.apache.cassandra.db.compaction.AbstractCompactionStrategy

filterSuspectSSTables, getOptions, getScanners

Methods inherited from class java.lang.Object

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

Constructor Detail

LeveledCompactionStrategy

public LeveledCompactionStrategy(ColumnFamilyStore cfs,
                                 java.util.Map<java.lang.String,java.lang.String> options)

Method Detail

shutdown

public void shutdown()

Description copied from class: AbstractCompactionStrategy

Releases any resources if this strategy is shutdown (when the CFS is reloaded after a schema change). Default is to do nothing.

Overrides:

shutdown in class AbstractCompactionStrategy

getLevelSize

public int getLevelSize(int i)

getNextBackgroundTask

public AbstractCompactionTask getNextBackgroundTask(int gcBefore)

the only difference between background and maximal in LCS is that maximal is still allowed (by explicit user request) even when compaction is disabled.

Specified by:

getNextBackgroundTask in class AbstractCompactionStrategy

Parameters:

gcBefore - throw away tombstones older than this

Returns:

the next background/minor compaction task to run; null if nothing to do.

getMaximalTask

public AbstractCompactionTask getMaximalTask(int gcBefore)

Specified by:

getMaximalTask in class AbstractCompactionStrategy

Parameters:

gcBefore - throw away tombstones older than this

Returns:

a compaction task that should be run to compact this columnfamilystore as much as possible. Null if nothing to do.

getUserDefinedTask

public AbstractCompactionTask getUserDefinedTask(java.util.Collection<SSTableReader> sstables,
                                                 int gcBefore)

Specified by:

getUserDefinedTask in class AbstractCompactionStrategy

gcBefore - throw away tombstones older than this

Returns:

a compaction task corresponding to the requested sstables. Will not be null. (Will throw if user requests an invalid compaction.)

getEstimatedRemainingTasks

public int getEstimatedRemainingTasks()

Specified by:

getEstimatedRemainingTasks in class AbstractCompactionStrategy

Returns:

the number of background tasks estimated to still be needed for this columnfamilystore

handleNotification

public void handleNotification(INotification notification,
                               java.lang.Object sender)

Specified by:

handleNotification in interface INotificationConsumer

getMaxSSTableSize

public long getMaxSSTableSize()

Specified by:

getMaxSSTableSize in class AbstractCompactionStrategy

Returns:

size in bytes of the largest sstables for this strategy

isKeyExistenceExpensive

public boolean isKeyExistenceExpensive(java.util.Set<? extends SSTable> sstablesToIgnore)

Specified by:

isKeyExistenceExpensive in class AbstractCompactionStrategy

Returns:

true if checking for whether a key exists, ignoring @param sstablesToIgnore, is going to be expensive

getScanners

public java.util.List<ICompactionScanner> getScanners(java.util.Collection<SSTableReader> sstables,
                                                      Range<Token> range)
                                               throws java.io.IOException

Description copied from class: AbstractCompactionStrategy

Returns a list of KeyScanners given sstables and a range on which to scan. The default implementation simply grab one SSTableScanner per-sstable, but overriding this method allow for a more memory efficient solution if we know the sstable don't overlap (see LeveledCompactionStrategy for instance).

Overrides:

getScanners in class AbstractCompactionStrategy

Throws:

java.io.IOException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object