Package org.apache.cassandra.db.compaction

Class UnifiedCompactionStrategy

java.lang.Object

org.apache.cassandra.db.compaction.AbstractCompactionStrategy

org.apache.cassandra.db.compaction.UnifiedCompactionStrategy

public class UnifiedCompactionStrategy
extends AbstractCompactionStrategy

The design of the unified compaction strategy is described in the accompanying UnifiedCompactionStrategy.md. See CEP-26: https://cwiki.apache.org/confluence/display/CASSANDRA/CEP-26%3A+Unified+Compaction+Strategy

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	UnifiedCompactionStrategy.Level	A level: index, sstables and some properties.
static class	UnifiedCompactionStrategy.MultiSetBucket
static class	UnifiedCompactionStrategy.SimpleBucket

Nested classes/interfaces inherited from class org.apache.cassandra.db.compaction.AbstractCompactionStrategy

AbstractCompactionStrategy.ScannerList

Field Summary

Fields

Modifier and Type	Field	Description
protected int	estimatedRemainingTasks
protected final Set<SSTableReader>	sstables

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

cfs, COMPACTION_ENABLED, DEFAULT_LOG_ALL_OPTION, DEFAULT_TOMBSTONE_COMPACTION_INTERVAL, DEFAULT_TOMBSTONE_THRESHOLD, DEFAULT_UNCHECKED_TOMBSTONE_COMPACTION_OPTION, disableTombstoneCompactions, isActive, LOG_ALL_OPTION, logAll, ONLY_PURGE_REPAIRED_TOMBSTONES, options, TOMBSTONE_COMPACTION_INTERVAL_OPTION, TOMBSTONE_THRESHOLD_OPTION, tombstoneCompactionInterval, tombstoneThreshold, UNCHECKED_TOMBSTONE_COMPACTION_OPTION, uncheckedTombstoneCompaction

Constructor Summary

Constructors

Constructor	Description
UnifiedCompactionStrategy(ColumnFamilyStore cfs, Map<String,String> options)
UnifiedCompactionStrategy(ColumnFamilyStore cfs, Map<String,String> options, Controller controller)

Method Summary

Modifier and Type	Method	Description
void	addSSTable(SSTableReader added)	Adds sstable, note that implementations must handle duplicate notifications here (added already being in the compaction strategy)
SSTableMultiWriter	createSSTableMultiWriter(Descriptor descriptor, long keyCount, long repairedAt, TimeUUID pendingRepair, boolean isTransient, IntervalSet<CommitLogPosition> commitLogPositions, int sstableLevel, SerializationHeader header, Collection<Index.Group> indexGroups, LifecycleNewTracker lifecycleNewTracker)	Create the sstable writer used for flushing.
static int	fanoutFromScalingParameter(int w)
Controller	getController()
int	getEstimatedRemainingTasks()
List<UnifiedCompactionStrategy.Level>	getLevels(Collection<SSTableReader> sstables, com.google.common.base.Predicate<SSTableReader> compactionFilter)	Groups the sstables passed in into levels.
Collection<AbstractCompactionTask>	getMaximalTask(long gcBefore, boolean splitOutput)
long	getMaxSSTableBytes()
TableMetadata	getMetadata()
UnifiedCompactionTask	getNextBackgroundTask(long gcBefore)	Returns a compaction task to run next.
protected Set<SSTableReader>	getSSTables()	Returns the sstables managed by this strategy instance
AbstractCompactionTask	getUserDefinedTask(Collection<SSTableReader> sstables, long gcBefore)
static boolean	isSuitableForCompaction(SSTableReader rdr)
static int	parseScalingParameter(String value)
static String	printScalingParameter(int w)
void	removeSSTable(SSTableReader sstable)	Removes sstable from the strategy, implementations must be able to handle the sstable having already been removed.
static int	thresholdFromScalingParameter(int w)
String	toString()
static Map<String,String>	validateOptions(Map<String,String> options)

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

addSSTables, filterSuspectSSTables, getCompactionTask, getDirectories, getName, getScanners, getScanners, getScanners, groupSSTablesForAntiCompaction, metadataChanged, pause, removeSSTables, replaceSSTables, resume, shutdown, startup, strategyLogger, supportsEarlyOpen, worthDroppingTombstones

Methods inherited from class java.lang.Object

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

Field Details

estimatedRemainingTasks

protected volatile int estimatedRemainingTasks

sstables

protected final Set<SSTableReader> sstables

Constructor Details

UnifiedCompactionStrategy

public UnifiedCompactionStrategy(ColumnFamilyStore cfs,
 Map<String,String> options)

UnifiedCompactionStrategy

public UnifiedCompactionStrategy(ColumnFamilyStore cfs,
 Map<String,String> options,
 Controller controller)

Method Details

validateOptions

public static Map<String,String> validateOptions(Map<String,String> options)
                                          throws ConfigurationException

Throws:

ConfigurationException

fanoutFromScalingParameter

public static int fanoutFromScalingParameter(int w)

thresholdFromScalingParameter

public static int thresholdFromScalingParameter(int w)

parseScalingParameter

public static int parseScalingParameter(String value)

printScalingParameter

public static String printScalingParameter(int w)

getMaximalTask

public Collection<AbstractCompactionTask> getMaximalTask(long gcBefore,
 boolean splitOutput)

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. Is responsible for marking its sstables as compaction-pending.

getUserDefinedTask

public AbstractCompactionTask getUserDefinedTask(Collection<SSTableReader> sstables,
 long gcBefore)

Specified by:

getUserDefinedTask in class AbstractCompactionStrategy

Parameters:

sstables - SSTables to compact. Must be marked as compacting.

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.) Is responsible for marking its sstables as compaction-pending.

getNextBackgroundTask

public UnifiedCompactionTask getNextBackgroundTask(long gcBefore)

Returns a compaction task to run next. This method is synchronized because task creation is significantly more expensive in UCS; the strategy is stateless, therefore it has to compute the shard/bucket structure on each call.

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. Is responsible for marking its sstables as compaction-pending.

createSSTableMultiWriter

public SSTableMultiWriter createSSTableMultiWriter(Descriptor descriptor,
 long keyCount,
 long repairedAt,
 TimeUUID pendingRepair,
 boolean isTransient,
 IntervalSet<CommitLogPosition> commitLogPositions,
 int sstableLevel,
 SerializationHeader header,
 Collection<Index.Group> indexGroups,
 LifecycleNewTracker lifecycleNewTracker)

Create the sstable writer used for flushing.

Overrides:

createSSTableMultiWriter in class AbstractCompactionStrategy

Returns:

an sstable writer that will split sstables into a number of shards as calculated by the controller for the expected flush density.

getEstimatedRemainingTasks

public int getEstimatedRemainingTasks()

Specified by:

getEstimatedRemainingTasks in class AbstractCompactionStrategy

Returns:

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

getMaxSSTableBytes

public long getMaxSSTableBytes()

Specified by:

getMaxSSTableBytes in class AbstractCompactionStrategy

Returns:

size in bytes of the largest sstables for this strategy

getController

public Controller getController()

isSuitableForCompaction

public static boolean isSuitableForCompaction(SSTableReader rdr)

addSSTable

public void addSSTable(SSTableReader added)

Description copied from class: AbstractCompactionStrategy

Adds sstable, note that implementations must handle duplicate notifications here (added already being in the compaction strategy)

Specified by:

addSSTable in class AbstractCompactionStrategy

removeSSTable

public void removeSSTable(SSTableReader sstable)

Description copied from class: AbstractCompactionStrategy

Removes sstable from the strategy, implementations must be able to handle the sstable having already been removed.

Specified by:

removeSSTable in class AbstractCompactionStrategy

getSSTables

protected Set<SSTableReader> getSSTables()

Description copied from class: AbstractCompactionStrategy

Returns the sstables managed by this strategy instance

Specified by:

getSSTables in class AbstractCompactionStrategy

getLevels

public List<UnifiedCompactionStrategy.Level> getLevels(Collection<SSTableReader> sstables,
 com.google.common.base.Predicate<SSTableReader> compactionFilter)

Groups the sstables passed in into levels. This is used by the strategy to determine new compactions, and by external tools to analyze the strategy decisions.

Parameters:

sstables - a collection of the sstables to be assigned to levels

compactionFilter - a filter to exclude CompactionSSTables, e.g., isSuitableForCompaction(org.apache.cassandra.io.sstable.format.SSTableReader)

Returns:

a list of the levels in the compaction hierarchy

getMetadata

public TableMetadata getMetadata()

toString

public String toString()

Overrides:

toString in class Object