hi Jesús Have you tried to use `kafka-metadata-quorum.sh` to remove those "offline" nodes from voters? For example:
``` bin/kafka-metadata-quorum.sh --command remove-controller --controller-id ``` Best, Chia-Ping On 2026/05/29 06:32:27 Jesus Cea wrote: > In a personal cluster I used to have three kraft controllers, using > Kafka 4.2.0. > > Because of "reasons" (the cluster is a lab), I downsized the cluster and > now I only use a controller, just modifying "controller.quorum.voters" > to include only the surviving controller. > > Working fine so far. Yes, I know that a single controller is a risk. > > Today I upgraded the brokers and the controller to Kafka 4.3.0 and I > tried to upgrade de cluster version using "kafka-features.sh upgrade > --release-version 4.3", but it is complaining that "old" controllers, > offline and destroyed, are not compatible (they were Kafka 4.2.0 at the > time of decommission). > > 1. How can I get rid of those dead controllers still haunting me? > > 2. I have tried to migrate to dynamic controller membership, but just > changing "controller.quorum.voters" to > "controller.quorum.bootstrap.server" doesn't work, although it is > documented in > <https://kafka.apache.org/42/operations/kraft/?utm_source=chatgpt.com#update-kraft-config>. > > Is there a "how to"/tutorial documenting the procedure? > > Thanks! > > PS: I rather not simply destroy&recreate the cluster, because I want to > know how to get out of this just in case it happens in a "serious" kafka > cluster. > > -- > Jesús Cea Avión _/_/ _/_/_/ _/_/_/ > [email protected] - https://www.jcea.es/ _/_/ _/_/ _/_/ _/_/ _/_/ > Twitter: @jcea _/_/ _/_/ _/_/_/_/_/ > jabber / xmpp:[email protected] _/_/ _/_/ _/_/ _/_/ _/_/ > "Things are not so easy" _/_/ _/_/ _/_/ _/_/ _/_/ _/_/ > "My name is Dump, Core Dump" _/_/_/ _/_/_/ _/_/ _/_/ > "El amor es poner tu felicidad en la felicidad de otro" - Leibniz >
