kirktrue commented on code in PR #17411: URL: https://github.com/apache/kafka/pull/17411#discussion_r1800275825
########## clients/src/main/java/org/apache/kafka/clients/consumer/internals/AbstractHeartbeatRequestManager.java: ########## @@ -378,11 +378,17 @@ private void onErrorResponse(final R response, final long currentTimeMs) { case INVALID_REQUEST: case GROUP_MAX_SIZE_REACHED: case UNSUPPORTED_ASSIGNOR: - case UNSUPPORTED_VERSION: logger.error("{} failed due to {}: {}", heartbeatRequestName(), error, errorMessage); handleFatalFailure(error.exception(errorMessage)); break; + case UNSUPPORTED_VERSION: + message = "The cluster doesn't yet support the new consumer group protocol." + + " Set group.protocol=classic to revert to the classic protocol until the cluster is upgraded."; Review Comment: > If I'm not mistaken, there are multiple cases that could cause this error: > > 1. The cluster is < 4.0.0 and doesn't support the new `CONSUMER` group protocol > 2. The cluster is >= 4.0.0 but isn't configured to use the new coordinator > 3. The cluster is >= 4.0.0 and is configured to use the new coordinator but _isn't_ configured to support the new `CONSUMER` group protocol > > The wording in the proposed error message doesn't distinguish the cases, but perhaps that's a good thing? After posting my review I noticed that @dajac [proposed the wording for the error message](https://github.com/apache/kafka/pull/17411#discussion_r1796499895). As such, it's already been discussed, so I'm fine with it as is. The message gives users what they need to resolve so 👍 -- 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: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org