Hi All, I have a streams application with 3 instances with application-id set to applicationV1. The application uses processor API with reading from source topics, processing the data and writing to destination topic. Currently it consumes from 6 source topics however we don't need to process data any more from 2 of those topics so we removed 2 topics from the source topics list. We have configured Datadog dashboard to report and alert on consumer lag so after removing the 2 source topics and deploying application, we started getting several alerts about consumer lag on applicationV1 consumer group which is underlying consumer group of the streams application. When we looked at the consumer group from kafka-cli, we could see that the consumer group is reporting lag against the topics removed from source topic list which is reflecting as increasing lag on Datadog monitoring.
Can someone advise if this is expected behavior? In my opinion, this is not expected since streams application no more has those topics as part of source, it should not report lag on those.