KIP-814 — Static membership protocol should let the leader skip assignment

Accepted Kafka 3.2 Consumer

Extends the static membership protocol so that the group leader can return a `JOIN_GROUP` response indicating it should skip recomputing the partition assignment when it knows the assignment is unchanged. Currently, when a static leader rejoins the group, the coordinator silently designates it leader without informing it, causing the leader to send a stale assignment that wastes CPU and can trigger unnecessary rebalances.

Protocol Impact

JoinGroup

Details