Github user StephanEwen commented on the issue: https://github.com/apache/flink/pull/5634 I would suggest to approach this in a different way. 1. Idleness detection is something that watermark generation benefits from in general, not just in Kafka 2. Unless there is a very strong reason, I would not want to add anything anymore to the Kafka Connector. This connector implementation is so big already. We saw multiple issues in the past, where the Kafka Connector's complexity was the cause of problems.