KIP-951 — Leader discovery optimizations for the client

Accepted Kafka 3.7 ProtocolClient

Embeds new leader information (leader ID, epoch, host/port) directly in ProduceResponse and FetchResponse error payloads when a broker knows the current leader, eliminating or reducing the need for a separate Metadata RPC round-trip after a leadership change. The existing leader discovery path required an asynchronous Metadata refresh plus retry backoff before the client could resume producing or fetching, significantly increasing end-to-end latency during leader elections and cluster rolls.

Protocol Impact

Produce v10 · Fetch v16 · Metadata

Details