Hi David, Thanks for starting this important KIP.
I've just taken a quick look so far but I've got a couple of initial questions: 1) What happens if a non KRaft compatible broker (or with kafka.metadata.migration.enable set to false) joins the cluster after the migration is triggered? 2) In the Failure Modes section you mention a scenario where a write to ZK fails. What happens when the divergence limit is reached? Is this a fatal condition? How much divergence should we allow? Thanks, Mickael On Wed, Oct 5, 2022 at 12:20 AM David Arthur <mum...@gmail.com> wrote: > > Hey folks, I wanted to get the ball rolling on the discussion for the > ZooKeeper migration KIP. This KIP details how we plan to do an online > migration of metadata from ZooKeeper to KRaft as well as a rolling > upgrade of brokers to KRaft mode. > > The general idea is to keep KRaft and ZooKeeper in sync during the > migration, so both types of brokers can exist simultaneously. Then, > once everything is migrated and updated, we can turn off ZooKeeper > writes. > > This is a pretty complex KIP, so please take a look :) > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-866+ZooKeeper+to+KRaft+Migration > > Thanks! > David
