Glossary

Consumer rebalance (Kafka)

A Kafka consumer group rebalance redistributes partition assignments among active consumers when membership changes: a consumer joins, leaves, or is considered dead due to missed heartbeats or exceeded `max.poll.interval.ms`. During an eager rebalance, all consumers revoke assignments simultaneously — a stop-the-world pause. Cooperative assignors (Kafka 2.4+) move only partitions that must change.

Last updated: March 2026