apurtell edited a comment on pull request #3244: URL: https://github.com/apache/hbase/pull/3244#issuecomment-838973994
> Speaking out loud. During RU, the wal written by RS that has ENABLE_WAL_VALUE_COMPRESSION set to false died and another RS which was recently upgraded has the above property set to true. Will the new RS be able to decode the cell ? @shahrs87 Yes. Each WAL file carries metadata about compression particulars for the file, so we can set up the CompressionContext correctly no matter the site file defaults. This logic is in ProtobufLogReader.java. The inverse is not true, though. There is no downgrade scenario for when after an upgrade now new WALs have value compression enabled, and you want to downgrade to a version that does not support value compression. However this is the obvious expectation that comes with enabling a new optional feature, and will be documented in release notes. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
