org.apache.hadoop.hbase.regionserver.compactions

Class RatioBasedCompactionPolicy

java.lang.Object

org.apache.hadoop.hbase.regionserver.compactions.CompactionPolicy

org.apache.hadoop.hbase.regionserver.compactions.SortedCompactionPolicy

org.apache.hadoop.hbase.regionserver.compactions.RatioBasedCompactionPolicy

Direct Known Subclasses:

ExploringCompactionPolicy

public class RatioBasedCompactionPolicy
extends SortedCompactionPolicy

The default algorithm for selecting files for compaction. Combines the compaction configuration and the provisional file selection that it's given to produce the list of suitable candidates for compaction.

Field Summary

Fields inherited from class org.apache.hadoop.hbase.regionserver.compactions.CompactionPolicy

comConf, storeConfigInfo

Constructor Summary

Constructors

Constructor and Description
RatioBasedCompactionPolicy(Configuration conf, StoreConfigInformation storeConfigInfo)

Method Summary

Modifier and Type	Method and Description
protected java.util.ArrayList<HStoreFile>	applyCompactionPolicy(java.util.ArrayList<HStoreFile> candidates, boolean mayUseOffPeak, boolean mayBeStuck) -- Default minor compaction selection algorithm: choose CompactSelection from candidates -- First exclude bulk-load files if indicated in configuration.
protected CompactionRequestImpl	createCompactionRequest(java.util.ArrayList<HStoreFile> candidateSelection, boolean tryingMajor, boolean mayUseOffPeak, boolean mayBeStuck)
boolean	needsCompaction(java.util.Collection<HStoreFile> storeFiles, java.util.List<HStoreFile> filesCompacting) A heuristic method to decide whether to schedule a compaction request
void	setMinThreshold(int minThreshold) Overwrite min threshold for compaction
boolean	shouldPerformMajorCompaction(java.util.Collection<HStoreFile> filesToCompact)

Methods inherited from class org.apache.hadoop.hbase.regionserver.compactions.SortedCompactionPolicy

checkMinFilesCriteria, filterBulk, getCurrentEligibleFiles, getNextMajorCompactTime, preSelectCompactionForCoprocessor, removeExcessFiles, selectCompaction, skipLargeFiles, throttleCompaction

Methods inherited from class org.apache.hadoop.hbase.regionserver.compactions.CompactionPolicy

getConf, setConf

Methods inherited from class java.lang.Object

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

Constructor Detail

RatioBasedCompactionPolicy

public RatioBasedCompactionPolicy(Configuration conf,
                                  StoreConfigInformation storeConfigInfo)

Method Detail

shouldPerformMajorCompaction

public boolean shouldPerformMajorCompaction(java.util.Collection<HStoreFile> filesToCompact)
                                     throws java.io.IOException

Specified by:

shouldPerformMajorCompaction in class SortedCompactionPolicy

Parameters:

filesToCompact - Files to compact. Can be null.

Returns:

True if we should run a major compaction.

Throws:

java.io.IOException

createCompactionRequest

protected CompactionRequestImpl createCompactionRequest(java.util.ArrayList<HStoreFile> candidateSelection,
                                                        boolean tryingMajor,
                                                        boolean mayUseOffPeak,
                                                        boolean mayBeStuck)
                                                 throws java.io.IOException

Specified by:

createCompactionRequest in class SortedCompactionPolicy

Throws:

java.io.IOException

applyCompactionPolicy

protected java.util.ArrayList<HStoreFile> applyCompactionPolicy(java.util.ArrayList<HStoreFile> candidates,
                                                                boolean mayUseOffPeak,
                                                                boolean mayBeStuck)
                                                         throws java.io.IOException

-- Default minor compaction selection algorithm: choose CompactSelection from candidates -- First exclude bulk-load files if indicated in configuration. Start at the oldest file and stop when you find the first file that meets compaction criteria: (1) a recently-flushed, small file (i.e. <= minCompactSize) OR (2) within the compactRatio of sum(newer_files) Given normal skew, any newer files will also meet this criteria

Additional Note: If fileSizes.size() >> maxFilesToCompact, we will recurse on compact(). Consider the oldest files first to avoid a situation where we always compact [end-threshold,end). Then, the last file becomes an aggregate of the previous compactions. normal skew: older ----> newer (increasing seqID) _ | | _ | | | | _ --|-|- |-|- |-|---_-------_------- minCompactSize | | | | | | | | _ | | | | | | | | | | | | | | | | | | | | | | | | | |

Parameters:

candidates - pre-filtrate

Returns:

filtered subset

Throws:

java.io.IOException

needsCompaction

public boolean needsCompaction(java.util.Collection<HStoreFile> storeFiles,
                               java.util.List<HStoreFile> filesCompacting)

A heuristic method to decide whether to schedule a compaction request

Specified by:

needsCompaction in class SortedCompactionPolicy

Parameters:

storeFiles - files in the store.

filesCompacting - files being scheduled to compact.

Returns:

true to schedule a request.

setMinThreshold

public void setMinThreshold(int minThreshold)

Overwrite min threshold for compaction