apurtell edited a comment on pull request #3360: URL: https://github.com/apache/hbase/pull/3360#issuecomment-855306586
The main issue with https://github.com/apache/hbase/pull/3352 is serializing commits with the act of getting the time requires that everything that might mutate the resource you are trying to protect must be within that scope. For a single row update the scope would be a row, and highly granular, so performance will not be affected that much. For batch mutations, which are typical, the scope is the region, and serializing commits to a region is expensive. I struggled for a while with various forms of hierarchical clocks where one might get a clock for the region, then use that clock to get child clocks for a row, and was not successful because they always ended up serializing *something* at region scope, but then reconsidered... What is it we are really tracking? Why not track that explicitly? It seemed much simpler in retrospect. Hence this PR, to explore that idea instead. -- 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]
