[KAFKA-13029] FindCoordinators batching can break consumers during rolling upgrade

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 3.0.0
• Component/s: consumer
• Assignee: Rajini Sivaram
• Reporter: Rajini Sivaram
• Created: 02/Jul/21 18:30
• Updated: 07/Jul/21 08:35
• Resolved: 07/Jul/21 08:35

Description

The changes made under KIP-699 assume that it is always safe to use unbatched mode since we move from batched to unbatched and cache the value forever in clients if a broker doesn't support batching. During rolling upgrade, if a request is sent to an older broker, we move from batched to unbatched mode. The consumer (admin client as well I think) disables batching and future requests to upgraded brokers will fail because we attempt to use unbatched requests with a newer version of the request.

Issue Links

• links to: GitHub Pull Request #10965