After watching the video from the Kafka Summit talk https://www.confluent.io/kafka-summit-nyc17/introducing-exactly-once-semantics-in-apache-kafka/ https://www.

After watching the video from the Kafka Summit talk https://www.confluent.io/kafka-summit-nyc17/introducing-exactly-once-semantics-in-apache-kafka/ https://www.confluent.io/kafka-summit-nyc17/introducing-exac... it's an essentially-useless guarantee for any sort of Kafka consumer that interacts with an external system. Exactly-Once is not something that can be provided-for or delegated-to an arbitrary, non-integrated system. For an "integrated" system, it requires idempotent behavior, in which case it's really At-Least-Once, so...