Multi-Point Region Division

Function

You can perform multi-point division by using org.apache.hadoop.hbase.client.HBaseAdmin. Note that the division operations take effect on empty regions only.

In this example, the multi-point division is performed on an HBase table by using multiSplit. The table will be split into 5 parts: "-∞~A", "A~D", "D~F", "F~H", and "H~+∞".

Example Code

The following code snippet belongs to the testMultiSplit method in the HBaseSample class of the com.huawei.bigdata.hbase.examples package.

public void testMultiSplit() {
    LOG.info("Entering testMultiSplit.");

    Table table = null;
    Admin admin = null;
    try {
      admin = conn.getAdmin();

      // initilize a HTable object
      table = conn.getTable(tableName);
      Set<HRegionInfo> regionSet = new HashSet<HRegionInfo>();
      List<HRegionLocation> regionList = conn.getRegionLocator(tableName).getAllRegionLocations();
      for(HRegionLocation hrl : regionList){
          regionSet.add(hrl.getRegionInfo());
      }
      byte[][] sk = new byte[4][];
      sk[0] = "A".getBytes();
      sk[1] = "D".getBytes();
      sk[2] = "F".getBytes();
      sk[3] = "H".getBytes();
      for (RegionInfo regionInfo : regionSet) {
        admin.multiSplitSync(regionInfo.getRegionName(), sk);
      }
      LOG.info("MultiSplit successfully.");
    } catch (Exception e) {
      LOG.error("MultiSplit failed.");
    } finally {
      if (table != null) {
        try {
          // Close table object
          table.close();
        } catch (IOException e) {
          LOG.error("Close table failed " ,e);
        }
      }
      if (admin != null) {
          try {
            // Close the Admin object.
            admin.close();
          } catch (IOException e) {
              LOG.error("Close admin failed " ,e);
          }
      }
    }
    LOG.info("Exiting testMultiSplit.");
  }     

Note that the division operations take effect on empty regions only.