@jeqo

Since Apache Kafka 3.0, Producers come with enable.idempotency=true which leads to acks=all, along with other changes enforced by idempotency. This means by default Producers will be balanced between latency (no batching) and durability — different from previous versions where the main goal was to reduce latency even by risking durability with acks=1.

Kafka Producers enforce durability across replicas by setting acks=all (default since v3.0). As enforcing this guarantee requires waiting for replicas to sync, this increases latency; and reducing it tends to give the impression that latency gets reduced overall.