KIP-134 — Delay initial consumer group rebalance

Accepted Kafka 1.0 Consumer

Introduces a group.initial.rebalance.delay.ms config that delays the initial rebalance of a new consumer group, giving members time to join before the first assignment is computed. Without this delay, each member joining triggers a new rebalance, causing O(N) rebalances for an N-member group startup — each one requiring stateful Streams apps to replay changelog topics.

Protocol Impact

JoinGroup

Details