com.neeve.rog.log

Class RogLogCompactor.Params

java.lang.Object

com.neeve.rog.log.RogLogCheckpointReaderParams

com.neeve.rog.log.RogLogCompactor.Params

Enclosing class:

RogLogCompactor

public static final class RogLogCompactor.Params
extends RogLogCheckpointReaderParams

Contains parameters for compaction.

Compactor parameters are set as properties in the StorePersisterDescriptor prefixed with 'compactor.' The paramateres may be set with StorePersisterDescriptor.setCompactorProperty(String, String).

Nested Class Summary

Nested classes/interfaces inherited from class com.neeve.rog.log.RogLogCheckpointReaderParams

RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy

Field Summary

Fields

Modifier and Type	Field and Description
static String	PROP_COMPACTION_THRESHOLD Property used to indicate the log compaction threshold The log compaction threshold is the size (in megabytes) that triggers a log compaction.
static String	PROP_COMPACTION_THRESHOLD_DEFAULT
static String	PROP_MAX_COMPACTION_WINDOW_SIZE Property used to indicate the max log compaction window size The log compaction window is the approximate maximum size (in megabytes) rounded up to the end of the nearest checkpoint that a compact operation uses to determine how many log entries it will hold in memory.
static String	PROP_MAX_COMPACTION_WINDOW_SIZE_DEFAULT

Fields inherited from class com.neeve.rog.log.RogLogCheckpointReaderParams

PROP_CONFLATE_CHECKPOINTS, PROP_CONFLATE_CHECKPOINTS_DEFAULT, PROP_ENTRY_RETENTION_THRESHOLD, PROP_ENTRY_RETENTION_THRESHOLD_DEFAULT, PROP_MEM_MAPPED_READ_BUFFER_LOAD, PROP_MEM_MAPPED_READ_BUFFER_LOAD_DEFAULT, PROP_MEM_MAPPED_READ_BUFFER_MAX_SIZE, PROP_MEM_MAPPED_READ_BUFFER_MAX_SIZE_DEFAULT, PROP_OFF_HEAP_BUFFERING, PROP_OFF_HEAP_BUFFERING_DEFAULT, PROP_OFF_HEAP_BUFFERING_LOAD_STRATEGY, PROP_OFF_HEAP_BUFFERING_LOAD_STRATEGY_DEFAULT, PROP_OFF_HEAP_BUFFERING_MAX_PAGE_SIZE, PROP_OFF_HEAP_BUFFERING_MAX_PAGE_SIZE_DEFAULT, PROP_SKIP_CDC_CHECKPOINTED, PROP_SKIP_CDC_CHECKPOINTED_DEFAULT

Method Summary

Methods

Modifier and Type	Method and Description
static RogLogCompactor.Params	create(Properties props) Loads cdc parameters from the give set of log descriptor properties.

Methods inherited from class java.lang.Object

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

Field Detail

PROP_MAX_COMPACTION_WINDOW_SIZE

public static final String PROP_MAX_COMPACTION_WINDOW_SIZE

Property used to indicate the max log compaction window size

The log compaction window is the approximate maximum size (in megabytes) rounded up to the end of the nearest checkpoint that a compact operation uses to determine how many log entries it will hold in memory. The more entries the compactor can hold in memory while performing a compaction, the more efficient the compact operation will be.

Note:

• The minimum compaction window is a checkpoint. Therefore, if the system is configured such that a checkpooint covers entries that cumulatively exceeds the value of this parameter, then this parameter will not reduce the compaction memory usage - the compator will load the entire checkpoint into memory when performing the checkpoint operation.
• When calculating memory needed by the compaction operation, one should multiply this parameter by a factor of 2 i.e. the memory used by compaction will be twice the memory specified via this parameter
• When RogLogCheckpointReaderParams.PROP_CONFLATE_CHECKPOINTS is false the compaction window is ignored in favor of a full conflation of the log in a non-windowed fashion. In this case heap memory usage is governed by the RogLogCheckpointReaderParams.PROP_ENTRY_RETENTION_THRESHOLD property and PROP_OFF_HEAP_BUFFERING settings.

See Also:

Constant Field Values

PROP_MAX_COMPACTION_WINDOW_SIZE_DEFAULT

public static final String PROP_MAX_COMPACTION_WINDOW_SIZE_DEFAULT

See Also:

Constant Field Values

PROP_COMPACTION_THRESHOLD

public static final String PROP_COMPACTION_THRESHOLD

Property used to indicate the log compaction threshold

The log compaction threshold is the size (in megabytes) that triggers a log compaction. The act of compacting a log will compact as many complete checkpoints in the log and switch the live log over to the compacted log. A threshold value of <= 0 disables live log compaction.

See Also:

Constant Field Values

PROP_COMPACTION_THRESHOLD_DEFAULT

public static final String PROP_COMPACTION_THRESHOLD_DEFAULT

See Also:

Constant Field Values

Method Detail

create

public static RogLogCompactor.Params create(Properties props)

Loads cdc parameters from the give set of log descriptor properties.

This method looks for cdc properties identifed with with the "cdc." prefix.

Parameters:

props - The properties to load from

Returns:

The parsed properties.