KIP-520 — Add overloaded Consumer#committed for batching partitions

Accepted Kafka 2.4 Consumer

Adds `Consumer.committed(Set<TopicPartition>)` and `Consumer.committed(Set<TopicPartition>, Duration)` overloads that fetch committed offsets for multiple partitions in a single `OffsetFetchRequest`, deprecating the single-partition variants. The single-partition `committed()` API issues one `OffsetFetchRequest` per partition, causing O(N) round-trips when an application needs offsets for a large partition set.

Protocol Impact

Fetch · OffsetFetch

Details