HBase fixed regions: Java

February 10, 2021

What's inside this article ⌄

How to create HBase table with the specified number of regions in HBase Shell
HBase constant number of regions
HBase constant reginos
HBase table fixed regions
HBase fixed regions

Let’s say we need to create an HBase table with a certain constant number of regions.

Regions pre-creation

First, we need to create a table with a certain pre-created number of regions. We can use one of the createTable() method overloads for that:

void createTable(TableDescriptor desc, byte[][] splitKeys);

We can make the byte[][] splitKeys array as follows:

byte[][] splitKeys = new RegionSplitter.HexStringSplit().split(n);

We need to add the hbase-server module (for example, version 1.2.3) to pom.xml:

<dependency>
    <groupId>org.apache.hbase</groupId>
    <artifactId>hbase-server</artifactId>
    <version>1.2.3</version>
</dependency>

WE can use another supported region split algorithm, for example, UniformSplit:

byte[][] splitKeys = new RegionSplitter.UniformSplit().split(n);

Disabling regions count autoincrease

For this purpose, we need to set RegionSplitPolicy through the TableDescriptor object, passed to the createTable() method:

HTableDescriptor htableDescr = new HTableDescriptor(tableName);
HColumnDescriptor hcolumnDescr = new HColumnDescriptor(COLUMN_FAMILY);
htableDescr.addFamily(hcolumnDescr);
htableDescr.setRegionSplitPolicyClassName(DisabledRegionSplitPolicy.class.getName());

Conclusion

The full code is:

HTableDescriptor htableDescr = new HTableDescriptor(tableName);
HColumnDescriptor hcolumnDescr = new HColumnDescriptor(COLUMN_FAMILY);
htableDescr.addFamily(hcolumnDescr);
htableDescr.setRegionSplitPolicyClassName(DisabledRegionSplitPolicy.class.getName());
byte[][] splitKeys = new RegionSplitter.HexStringSplit().split(n);
connection.getAdmin().createTable(htableDescr, splitKeys);