Package org.apache.hadoop.hbase.regionserver

Class RegionSplitRestriction

java.lang.Object
org.apache.hadoop.hbase.regionserver.RegionSplitRestriction
Direct Known Subclasses:
DelimitedKeyPrefixRegionSplitRestriction, KeyPrefixRegionSplitRestriction, NoRegionSplitRestriction
@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: