[KAFKA-14167] Unexpected UNKNOWN_SERVER_ERROR raised from kraft controller

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 3.3.0
• Assignee: Unassigned
• Reporter: Jason Gustafson
• Created: 15/Aug/22 23:38
• Updated: 18/Aug/22 01:16
• Resolved: 18/Aug/22 01:16

Description

In `ControllerApis`, we have callbacks such as the following after completion:

    controller.allocateProducerIds(context, allocatedProducerIdsRequest.data)
      .handle[Unit] { (results, exception) =>
        if (exception != null) {
          requestHelper.handleError(request, exception)
        } else {
          requestHelper.sendResponseMaybeThrottle(request, requestThrottleMs => {
            results.setThrottleTimeMs(requestThrottleMs)
            new AllocateProducerIdsResponse(results)
          })
        }
      } 

What I see locally is that the underlying exception that gets passed to `handle` always gets wrapped in a `CompletionException`. When passed to `getErrorResponse`, this error will get converted to `UNKNOWN_SERVER_ERROR`. For example, in this case, a `NOT_CONTROLLER` error returned from the controller would be returned as `UNKNOWN_SERVER_ERROR`. It looks like there are a few APIs that are potentially affected by this bug, such as `DeleteTopics` and `UpdateFeatures`.

Issue Links

• links to: GitHub Pull Request #12518