Thanks Luke. On Thu, Apr 3, 2025 at 7:14 AM Luke Chen <show...@gmail.com> wrote: > In addition to the approaches you provided, maybe we can have a way to > "force" KRaft to honor "controller.quorum.voters" config, instead of > "controller.quorum.bootstrap.servers", even it's in kraft.version 1.
Small clarification. In KIP-595, controller.quorum.voters was playing two roles. 1) the set voters used by KRaft during HWM calculation and leader election. 2) the set of endpoints used by observers (brokers) to discover the leader (active controller). In KIP-853, I split that functionality. The set of voters was moved to control records (VotersRecord) in the cluster metadata partition. The bootstrap endpoints used by observer/brokers to discover the leader were moved to the controller.quorum.bootstrap.servers property. I say that because Kafka supports using both configurations at the same time. This is useful when upgrading from kraft.version 0 to kraft.version 1. The upgrade process is roughly as follow: 1. Add the controller.quorum.bootstrap.servers to all of the nodes (controllers and brokers). 2. Upgrade the kraft.version from 0 to 1. 3. Monitor the "ignored-static-voters" metrics and remove the controller.quorum.voters when the metric is 1. Thanks, -- -José
