Kafka connector delivery guarantees

I’m wondering what delivery guarantees does kafka connector offer.

Thank you for your help!

For sink default is At Least Once. If there is an error when processing data from a topic the connector will retry the write. However, if the data on the topic contains a unique attribute, it is possible to achieve exactly once semantics by configuring the Sink connector to use upserts and the DocumentIdAdder strategy. The sink connector can not support at most once.

For source default is At least once. There is a risk of duplicate messages if you use the copy.existing flag. Note that change stream events are idempotent so the need to support other delivery guarantees are not applicable.