cadonna commented on pull request #9821: URL: https://github.com/apache/kafka/pull/9821#issuecomment-822384633
@vitojeng @mjsax @ableegoldman My 2 euro cent: Looking at the code for `allMetadataForStore` and `queryMetadataForKey` it seems like the case when a state store is not unknown is not handled by throwing an exception but by returning `null` or by returning `UNKNOWN_HOST`. Since it is documented (almost) that way in the javadocs and the relevant KIPs ([KIP-67](https://cwiki.apache.org/confluence/display/KAFKA/KIP-67%3A+Queryable+state+for+Kafka+Streams) and [KIP-535](https://cwiki.apache.org/confluence/display/KAFKA/KIP-535%3A+Allow+state+stores+to+serve+stale+reads+during+rebalance)) do not mention an exception, I think we need a proper update to the existing KIP or a new dedicated KIP for it (both with voting), because it does not seem to be an oversight in the implementation, but rather an oversight in the design of the API. If it were an oversight in then implementation you could argue that users relied on buggy code and a quick update on the KIP thread would be fine. However, with an oversight in the API design, I think a KIP with additions of new methods and deprecations of old methods is needed. If it is an update of the current KIP or a new one in order to not block the existing one is less important (although I am in favor of the latter). WDYT? -- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
