KIP-1113 — Enhancements to Rack-Aware Partition Assignor for Improved Client-Side Independence and Load Balancing

Discussion Consumer

KIP-1113 introduces `LeaderRackAwareCooperativeStickyAssignor` and `LeaderRackAwareRangeAssignor` partition assignors that assign partitions to consumers based on the rack of the partition's leader replica rather than follower replicas, always reading from the leader. The existing rack-aware assignor relies on `replica.selector.class=RackAwareReplicaSelector` on the broker (a broker-side config) and reads from follower replicas, violating Kafka's read-write consistency model and coupling client-side assignment strategy to broker configuration.

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