Hi Justine, Thanks for the KIP. I see that the KIP doesn't make any updates to the UpdateFeatures RPC. I was trying to understand how errors will be communicated to the client.
Are you planning to use the INVALID_UPDATE_VERSION error and overwrite the ErrorMessage field for all of the validations you mentioned in the KIP? I see that INVALID_UPDATE_VERSION is in the code for Apache Kafka but I couldn't find the KIP that adds this error. It is not in KIP-584 or KIP-778. If you agree, do you think we should document this error in this KIP? It is also not clear to me when the UpdateFeaturesResponse will return an error per feature versus an error for the entire RPC. KIP-584 defines this relationship but it doesn't specify when exactly a top level error will be returned versus when a feature level error will be returned. I think that most users wouldn't want partial failures. They instead would like to be guaranteed that all of the feature updates succeeded or none did. Do you agree? Should we update the KIP to make this clear? Thanks! -- -José
