Ismael, We need to discuss two cases for Connect:
1) Connect uses the classic rebalance protocol to assign its tasks within a Connect cluster. This will keep working until we figure out a plan to migrate this part to another protocol (e.g. Connect protocol following Streams protocol). This is completely orthogonal from the Consumer. 2) Connect uses Consumers in sources/sinks to read from topics. Those consumers can use the consumer rebalance protocol without any issues. They can just follow the upgrade path and use the new protocol when the config changes. This means that in 6.0, Connect's Consumer will use the new rebalance protocol whereas Connect's runtime will continue to use the classic protocol to distribute its tasks. Lianet, we should perhaps clarify this in the KIP. Best, David On Tue, Jan 27, 2026 at 4:27 PM Ismael Juma <[email protected]> wrote: > Lianet, > > Thanks for the KIP. I think this is a desirable goal, but it seems > premature without a plan for Connect. Removing the config for regular users > while allowing it for Connect seems problematic. While we figure the > details of that and the deprecation story for the classic rebalance > protocol, we could still agree to a log line during start-up recommending > `classic` users to switch to the switch to `consumer` (after appropriate > testing). > > Ismael > > On Thu, Jan 22, 2026 at 2:05 PM Lianet Magrans <[email protected]> wrote: > > > Hello, > > > > I would like to start the discussion for KIP-1274. This KIP proposes a > > phased plan to drive a smooth evolution of Java client consumer > > applications towards the next generation of the rebalance protocol > > > > Here is the KIP: > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-1274%3A+Deprecate+and+remove+support+for+Classic+rebalance+protocol+in+KafkaConsumer > > > > Looking forward to hearing from you, > > > > Thanks! > > Lianet > > >
