Feature request or enhancement

For feature requests or enhancements, provide this information, please:

Which use case/requirement will be addressed by the proposed feature?

For signal requests, presently the source signal channel consumes signal requests on connector start-up that were made during a downtime of the connector (e.g. due to a runtime error that caused the connector to stop or during a rolling upgrade when the connector is stopped and then started again).

However, the kafka signal channel does not support the aforementioned behaviour. It always starts consuming from the latest offset of the signal topic. Thus, even if snapshot requests are made during a downtime, they are ignored.

Implementation ideas (optional)

The blow proposal is based on the discussion from: https://debezium.zulipchat.com/#narrow/stream/302529-community-general/topic/Kafka.20signal.20channel.20ignores.20messages.20on.20signal.20topic/near/403157937

The discussion also contains some additional observations around the kafka signal channel.

The suggestion is to add support for persistent history. That support can also be configurable via an additional signal configuration property.