Andrew Kyle Purtell created HBASE-25869: -------------------------------------------
Summary: WAL value compression Key: HBASE-25869 URL: https://issues.apache.org/jira/browse/HBASE-25869 Project: HBase Issue Type: Bug Components: Operability, wal Reporter: Andrew Kyle Purtell Assignee: Andrew Kyle Purtell Fix For: 3.0.0-alpha-1, 2.5.0 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. We have a custom dictionary compression scheme for cell metadata that is engaged when WAL compression is enabled in site configuration. This is fine for that application, where we can expect the universe of values (and their lengths) in the custom dictionaries to be constrained. For arbitrary values it is better to use Deflate compression, which is reasonably fast, certainly fast enough for WALs, compresses well, and is universally available as part of the Java runtime. With a trick that encodes whether or not the cell value is compressed in the high order bit of the type byte, this can be done in a backwards compatible manner. -- This message was sent by Atlassian Jira (v8.3.4#803005)