dajac opened a new pull request, #12599: URL: https://github.com/apache/kafka/pull/12599
The consumer group instance ID is used to support a notion of "static" consumer groups. The idea is to be able to identify the same group instance across restarts so that a rebalance is not needed. However, if the user sets `group.instance.id` in the consumer configuration, but uses "simple" assignment with `assign()`, then the instance ID nevertheless is sent in the OffsetCommit request to the coordinator. This may result in a surprising UNKNOWN_MEMBER_ID error. This PR fixes the issue on the client side by not setting the group instance id if the member id is empty (no generation). ### Committer Checklist (excluded from commit message) - [ ] Verify design and implementation - [ ] Verify test coverage and CI build status - [ ] Verify documentation (including upgrade 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
