alpinegizmo commented on code in PR #28863: URL: https://github.com/apache/flink/pull/28863#discussion_r3826063230
########## docs/content/docs/concepts/glossary.md: ########## @@ -231,6 +231,17 @@ a finished Job. Each result contains the Job's identifier, final state, name, th belongs to, etc. These results are then used by Flink to determine whether Jobs should be subject to recovery in highly-available Clusters. +#### Key Group + +A Key Group is the atomic unit of key distribution and state assignment across parallel +[Sub-Tasks](#sub-task). Every key is mapped deterministically to a Key Group based on +`keyGroupIndex = MathUtils.murmurHash(key.hashCode()) % maxParallelism`. +This allows stateful [Operators](#operator) to rescale without rehashing individual keys. + +The total number of Key Groups is equal to the [Operator](#operator)'s `maxParallelism`. Review Comment: I think it's confusing to imply that maxParallelism is a property of the Operator. -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
