Using Apache HBase to store and access data
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Physical size of the data

The physical size of data on disk is affected by factors such as HBase overhead, compression, replication and RegionServer Write Ahead Log (WAL).

Factor Affecting Size of Physical Data


HBase Overhead

The default amount of disk space required for a single HBase table cell. Smaller table cells require less overhead. The minimum cell size is 24 bytes and the default maximum is 10485760 bytes.

You can customize the maximum cell size by using the hbase.client.keyvalue.maxsize property in the hbase-site.xml configuration file. HBase table cells are aggregated into blocks; you can configure the block size for each column family by using the hbase.mapreduce.hfileoutputformat.blocksize property. The default value is 65536 bytes. You can reduce this value for tables with highly random data access patterns if you want to improve query latency.


You should choose the data compression tool that is most appropriate to reducing the physical size of your data on disk. Although HBase is not shipped with LZO due to licensing issues, you can install LZO after installing HBase. GZIP provides better compression than LZO but is slower. HBase also supports Snappy.

HDFS Replication

HBase uses HDFS for storage, so replicating HBase data stored in HDFS affects the total physical size of data. A typical replication factor of 3 for all HBase tables in a cluster triples the physical size of the stored data.

RegionServer Write Ahead Log (WAL)

The size of the Write Ahead Log, or WAL, for each RegionServer has minimal impact on the physical size of data: typically fixed at less than half of the memory for the RegionServer. The data size of WAL is usually not configured.