Rebalance

Rebalance is the process by which the Consumer Group coordinator redistributes a topic's partitions among the active consumers, whenever the group's membership changes — a consumer goes down, a new one joins, or a consumer is considered dead for not sending a heartbeat in time. During the rebalance, the group's consumption pauses briefly while partitions are reassigned; more recent rebalance strategies (cooperative sticky) reduce that impact by avoiding revoking partitions from consumers that remain active.