org.apache.hadoop.hbase.regionserver

Class RegionSplitRestriction

java.lang.Object

org.apache.hadoop.hbase.regionserver.RegionSplitRestriction

Direct Known Subclasses:

DelimitedKeyPrefixRegionSplitRestriction, KeyPrefixRegionSplitRestriction, NoRegionSplitRestriction

@InterfaceAudience.Private
public abstract class RegionSplitRestriction
extends Object

A split restriction that restricts the pattern of the split point.

The difference between RegionSplitPolicy and RegionSplitRestriction is that RegionSplitRestriction defines how to split while RegionSplitPolicy defines when we need to split.

We can specify a split restriction, "KeyPrefix" or "DelimitedKeyPrefix", to a table with the "hbase.regionserver.region.split_restriction.type" property. The "KeyPrefix" split restriction groups rows by a prefix of the row-key. And the "DelimitedKeyPrefix" split restriction groups rows by a prefix of the row-key with a delimiter. For example:

 
 # Create a table with a "KeyPrefix" split restriction, where the prefix length is 2 bytes
 hbase> create 'tbl1', 'fam',
   {CONFIGURATION => {'hbase.regionserver.region.split_restriction.type' => 'KeyPrefix',
                      'hbase.regionserver.region.split_restriction.prefix_length' => '2'}}

 # Create a table with a "DelimitedKeyPrefix" split restriction, where the delimiter is a comma
 hbase> create 'tbl2', 'fam',
   {CONFIGURATION => {'hbase.regionserver.region.split_restriction.type' => 'DelimitedKeyPrefix',
                      'hbase.regionserver.region.split_restriction.delimiter' => ','}}
 
 

Instead of specifying a split restriction to a table directly, we can also set the properties in hbase-site.xml. In this case, the specified split restriction is applied for all the tables.

Note that the split restriction is also applied to a user-specified split point so that we don't allow users to break the restriction.

See Also:

NoRegionSplitRestriction, KeyPrefixRegionSplitRestriction, DelimitedKeyPrefixRegionSplitRestriction

Field Summary

Fields

Modifier and Type	Field and Description
private static org.slf4j.Logger	LOG
static String	RESTRICTION_TYPE_DELIMITED_KEY_PREFIX
static String	RESTRICTION_TYPE_KEY
static String	RESTRICTION_TYPE_KEY_PREFIX
static String	RESTRICTION_TYPE_NONE

Constructor Summary

Constructors

Constructor and Description
RegionSplitRestriction()

Method Summary

Modifier and Type	Method and Description
static RegionSplitRestriction	create(TableDescriptor tableDescriptor, org.apache.hadoop.conf.Configuration conf) Create the RegionSplitRestriction configured for the given table.
abstract byte[]	getRestrictedSplitPoint(byte[] splitPoint) Returns a restricted split point.
abstract void	initialize(TableDescriptor tableDescriptor, org.apache.hadoop.conf.Configuration conf) Initialize the RegionSplitRestriction instance

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final org.slf4j.Logger LOG

RESTRICTION_TYPE_KEY

public static final String RESTRICTION_TYPE_KEY

See Also:

Constant Field Values

RESTRICTION_TYPE_NONE

public static final String RESTRICTION_TYPE_NONE

See Also:

Constant Field Values

RESTRICTION_TYPE_KEY_PREFIX

public static final String RESTRICTION_TYPE_KEY_PREFIX

See Also:

Constant Field Values

RESTRICTION_TYPE_DELIMITED_KEY_PREFIX

public static final String RESTRICTION_TYPE_DELIMITED_KEY_PREFIX

See Also:

Constant Field Values

Constructor Detail

RegionSplitRestriction

public RegionSplitRestriction()

Method Detail

create

public static RegionSplitRestriction create(TableDescriptor tableDescriptor,
                                            org.apache.hadoop.conf.Configuration conf)
                                     throws IOException

Create the RegionSplitRestriction configured for the given table.

Parameters:

tableDescriptor - the table descriptor

conf - the configuration

Returns:

a RegionSplitRestriction instance

Throws:

IOException - if an error occurs

initialize

public abstract void initialize(TableDescriptor tableDescriptor,
                                org.apache.hadoop.conf.Configuration conf)
                         throws IOException

Initialize the RegionSplitRestriction instance

Parameters:

tableDescriptor - the table descriptor

conf - the configuration

Throws:

IOException - if an error occurs

getRestrictedSplitPoint

public abstract byte[] getRestrictedSplitPoint(byte[] splitPoint)

Returns a restricted split point.

Parameters:

splitPoint - the split point determined by RegionSplitPolicy or specified by a user manually

Returns:

the restricted split point