WAL value compression

WAL storage can be expensive, especially if the cell values represented in the edits are large, consisting of blobs or significant lengths of text. Such WALs might need to be kept around for a fairly long time to satisfy replication constraints on a space limited (or space-contended) filesystem. Enable WAL compression and, with this feature, WAL value compression, to save space in exchange for slightly higher WAL append latencies. The degree of performance impact will depend on the compression algorithm selection. SNAPPY or ZSTD are recommended algorithms, if native codec support is available. SNAPPY may even provide an overall improvement in WAL commit latency, so is the best choice. GZ can be a reasonable fallback where native codec support is not available. To enable WAL compression, value compression, and select the desired algorithm, edit your site configuration like so: <!-- to enable compression --> <property>     <name>hbase.regionserver.wal.enablecompression</name>     <value>true</value> </property> <!-- to enable value compression --> <property>     <name>hbase.regionserver.wal.value.enablecompression</name>     <value>true</value> </property> <!-- choose the value compression algorithm —> <property>     <name>hbase.regionserver.wal.value.compression.type</name>     <value>snappy</value> </property>