If your workload demands it, then by all means set log.flush.interval.messages=1 or find an alternative solution that is a better match for your requirements.

If your workload demands it, then by all means set log.flush.interval.messages=1 or find an alternative solution that is a better match for your requirements. Kafka has never pretended that ack'd messages have been persisted to disk, only that they've been replicated per your requested acks.