org.apache.hadoop.hbase.regionserver

Class RegionSplitPolicy

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.hbase.regionserver.RegionSplitPolicy

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable

Direct Known Subclasses:

ConstantSizeRegionSplitPolicy, DisabledRegionSplitPolicy

@InterfaceAudience.LimitedPrivate(value="Configuration")
public abstract class RegionSplitPolicy
extends org.apache.hadoop.conf.Configured

A split policy determines when a Region should be split.

See Also:

Default split policy since 2.0.0, Default split policy since 0.94.0, Default split policy before 0.94.0

Field Summary

Fields

Modifier and Type	Field and Description
private static Class<? extends RegionSplitPolicy>	DEFAULT_SPLIT_POLICY_CLASS
protected HRegion	region The region configured for this split policy.

Constructor Summary

Constructors

Constructor and Description
RegionSplitPolicy()

Method Summary

Modifier and Type	Method and Description
protected boolean	canSplit() Returns true if the specified region can be split.
protected void	configureForRegion(HRegion region) Upon construction, this method will be called with the region to be governed.
static RegionSplitPolicy	create(HRegion region, org.apache.hadoop.conf.Configuration conf) Create the RegionSplitPolicy configured for the given table.
protected byte[]	getSplitPoint()
static Class<? extends RegionSplitPolicy>	getSplitPolicyClass(TableDescriptor htd, org.apache.hadoop.conf.Configuration conf)
protected abstract boolean	shouldSplit() Returns true if the specified region should be split.
protected boolean	skipStoreFileRangeCheck(String familyName) In HRegionFileSystem.splitStoreFile(org.apache.hadoop.hbase.client.RegionInfo, String, HStoreFile, byte[], boolean, RegionSplitPolicy) we are not creating the split reference if split row does not lie inside the StoreFile range.

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_SPLIT_POLICY_CLASS

private static final Class<? extends RegionSplitPolicy> DEFAULT_SPLIT_POLICY_CLASS

region

protected HRegion region

The region configured for this split policy. As of hbase-2.0.0, RegionSplitPolicy can be instantiated on the Master-side so the Phoenix local-indexer can block default hbase behavior. This is an exotic usage. Should not trouble any other users of RegionSplitPolicy.

Constructor Detail

RegionSplitPolicy

public RegionSplitPolicy()

Method Detail

configureForRegion

protected void configureForRegion(HRegion region)

Upon construction, this method will be called with the region to be governed. It will be called once and only once.

shouldSplit

protected abstract boolean shouldSplit()

Returns true if the specified region should be split.

canSplit

protected boolean canSplit()

Returns true if the specified region can be split.

getSplitPoint

protected byte[] getSplitPoint()

Returns:

the key at which the region should be split, or null if it cannot be split. This will only be called if shouldSplit previously returned true.

create

public static RegionSplitPolicy create(HRegion region,
                                       org.apache.hadoop.conf.Configuration conf)
                                throws IOException

Create the RegionSplitPolicy configured for the given table. nn * @return a RegionSplitPolicy n

Throws:

IOException

getSplitPolicyClass

public static Class<? extends RegionSplitPolicy> getSplitPolicyClass(TableDescriptor htd,
                                                                     org.apache.hadoop.conf.Configuration conf)
                                                              throws IOException

Throws:

IOException

skipStoreFileRangeCheck

protected boolean skipStoreFileRangeCheck(String familyName)

In HRegionFileSystem.splitStoreFile(org.apache.hadoop.hbase.client.RegionInfo, String, HStoreFile, byte[], boolean, RegionSplitPolicy) we are not creating the split reference if split row does not lie inside the StoreFile range. But in some use cases we may need to create the split reference even when the split row does not lie inside the StoreFile range. This method can be used to decide, whether to skip the the StoreFile range check or not.

This method is not for general use. It is a mechanism put in place by Phoenix local indexing to defeat standard hbase behaviors. Phoenix local indices are very likely the only folks who would make use of this method. On the Master-side, we will instantiate a RegionSplitPolicy instance and run this method ONLY... none of the others make sense on the Master-side.

TODO: Shutdown this phoenix specialization or do it via some other means.

Returns:

whether to skip the StoreFile range check or not