Package org.apache.iotdb.db.engine.compaction.inner.sizetiered

Class SizeTieredCompactionSelector

java.lang.Object

org.apache.iotdb.db.engine.compaction.inner.sizetiered.SizeTieredCompactionSelector

All Implemented Interfaces:

IInnerSeqSpaceSelector, IInnerUnseqSpaceSelector, ICompactionSelector

public class SizeTieredCompactionSelector
extends java.lang.Object
implements IInnerSeqSpaceSelector, IInnerUnseqSpaceSelector

SizeTieredCompactionSelector selects files to be compacted based on the size of files. The selector traverses the file list from old to new. If the size of selected files or the number of select files exceed given threshold, a compaction task will be submitted to task queue in CompactionTaskManager. In CompactionTaskManager, tasks are ordered by ICompactionTaskComparator. To maximize compaction efficiency, selector searches compaction task from 0 compaction files(that is, file that never been compacted, named level 0 file) to higher level files. If a compaction task is found in some level, selector will not search higher level anymore.

Field Summary

Fields

Modifier and Type	Field	Description
protected java.lang.String	dataRegionId
protected boolean	hasNextTimePartition
protected boolean	sequence
protected java.lang.String	storageGroupName
protected long	timePartition
protected TsFileManager	tsFileManager
protected java.util.List<TsFileResource>	tsFileResources

Constructor Summary

Constructors

Constructor	Description
SizeTieredCompactionSelector(java.lang.String storageGroupName, java.lang.String dataRegionId, long timePartition, boolean sequence, TsFileManager tsFileManager)

Method Summary

Modifier and Type	Method	Description
java.util.List<java.util.List<TsFileResource>>	selectInnerSpaceTask(java.util.List<TsFileResource> tsFileResources)	This method searches for a batch of files to be compacted from layer 0 to the highest layer.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.iotdb.db.engine.compaction.task.ICompactionSelector

getCompactionMemoryCost, selectCrossSpaceTask

Field Detail

storageGroupName

protected java.lang.String storageGroupName

dataRegionId

protected java.lang.String dataRegionId

timePartition

protected long timePartition

tsFileResources

protected java.util.List<TsFileResource> tsFileResources

sequence

protected boolean sequence

tsFileManager

protected TsFileManager tsFileManager

hasNextTimePartition

protected boolean hasNextTimePartition

Constructor Detail

SizeTieredCompactionSelector

public SizeTieredCompactionSelector(java.lang.String storageGroupName,
                                    java.lang.String dataRegionId,
                                    long timePartition,
                                    boolean sequence,
                                    TsFileManager tsFileManager)

Method Detail

selectInnerSpaceTask

public java.util.List<java.util.List<TsFileResource>> selectInnerSpaceTask(java.util.List<TsFileResource> tsFileResources)

This method searches for a batch of files to be compacted from layer 0 to the highest layer. If there are more than a batch of files to be merged on a certain layer, it does not search to higher layers. It creates a compaction thread for each batch of files and put it into the candidateCompactionTaskQueue of the CompactionTaskManager.

Specified by:

selectInnerSpaceTask in interface ICompactionSelector

Specified by:

selectInnerSpaceTask in interface IInnerSeqSpaceSelector

Specified by:

selectInnerSpaceTask in interface IInnerUnseqSpaceSelector

Returns:

Returns whether the file was found and submits the merge task