org.apache.cassandra.io.sstable

Class IndexSummaryManager

java.lang.Object

org.apache.cassandra.io.sstable.IndexSummaryManager

All Implemented Interfaces:

IndexSummaryManagerMBean

public class IndexSummaryManager
extends java.lang.Object
implements IndexSummaryManagerMBean

Manages the fixed-size memory pool for index summaries, periodically resizing them in order to give more memory to hot sstables and less memory to cold sstables.

Field Summary

Fields

Modifier and Type	Field and Description
static IndexSummaryManager	instance
static java.lang.String	MBEAN_NAME

Method Summary

Modifier and Type	Method and Description
double	getAverageIndexInterval()
java.util.Map<java.lang.String,java.lang.Integer>	getIndexIntervals() Returns a map of SSTable filenames to their current effective index interval.
long	getMemoryPoolCapacityInMB()
double	getMemoryPoolSizeInMB() Returns the actual space consumed by index summaries for all sstables.
int	getResizeIntervalInMinutes()
void	redistributeSummaries()
static java.util.List<SSTableReader>	redistributeSummaries(IndexSummaryRedistribution redistribution) Attempts to fairly distribute a fixed pool of memory for index summaries across a set of SSTables based on their recent read rates.
void	setMemoryPoolCapacityInMB(long memoryPoolCapacityInMB)
void	setResizeIntervalInMinutes(int resizeIntervalInMinutes)

Methods inherited from class java.lang.Object

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

Field Detail

MBEAN_NAME

public static final java.lang.String MBEAN_NAME

See Also:

Constant Field Values

instance

public static final IndexSummaryManager instance

Method Detail

getResizeIntervalInMinutes

public int getResizeIntervalInMinutes()

Specified by:

getResizeIntervalInMinutes in interface IndexSummaryManagerMBean

setResizeIntervalInMinutes

public void setResizeIntervalInMinutes(int resizeIntervalInMinutes)

Specified by:

setResizeIntervalInMinutes in interface IndexSummaryManagerMBean

getMemoryPoolCapacityInMB

public long getMemoryPoolCapacityInMB()

Specified by:

getMemoryPoolCapacityInMB in interface IndexSummaryManagerMBean

getIndexIntervals

public java.util.Map<java.lang.String,java.lang.Integer> getIndexIntervals()

Description copied from interface: IndexSummaryManagerMBean

Returns a map of SSTable filenames to their current effective index interval.

Specified by:

getIndexIntervals in interface IndexSummaryManagerMBean

getAverageIndexInterval

public double getAverageIndexInterval()

Specified by:

getAverageIndexInterval in interface IndexSummaryManagerMBean

setMemoryPoolCapacityInMB

public void setMemoryPoolCapacityInMB(long memoryPoolCapacityInMB)

Specified by:

setMemoryPoolCapacityInMB in interface IndexSummaryManagerMBean

getMemoryPoolSizeInMB

public double getMemoryPoolSizeInMB()

Returns the actual space consumed by index summaries for all sstables.

Specified by:

getMemoryPoolSizeInMB in interface IndexSummaryManagerMBean

Returns:

space currently used in MB

redistributeSummaries

public void redistributeSummaries()
                           throws java.io.IOException

Specified by:

redistributeSummaries in interface IndexSummaryManagerMBean

Throws:

java.io.IOException

redistributeSummaries

public static java.util.List<SSTableReader> redistributeSummaries(IndexSummaryRedistribution redistribution)
                                                           throws java.io.IOException

Attempts to fairly distribute a fixed pool of memory for index summaries across a set of SSTables based on their recent read rates.

Parameters:

redistribution - encapsulating the transactions containing the sstables we are to redistribute the memory pool across and a size (in bytes) that the total index summary space usage should stay close to or under, if possible

Returns:

a list of new SSTableReader instances

Throws:

java.io.IOException