Hey Vahid, Thanks for writing this up. This seems like a nice improvement over the existing somewhat surprising behavior. Currently if you have a consumer which changes subscriptions, then you will need to handle separately any cleanup for assigned partitions for topics which are no longer subscribed. With this change, the user can handle this exclusively in the onPartitionsRevoked() callback which seems less error prone. This also makes it unnecessary for us to do any special handling when autocommit is enabled since all partitions will still be assigned when we do the final offset commit prior to rebalancing. The main question mark in my mind is compatibility, but it seems unlikely that anyone depends on the current behavior. My hunch is that users probably expect it already works this way, so from that perspective, it's almost more of a bug fix.
Thanks, Jason On Tue, Jul 19, 2016 at 5:55 PM, Vahid S Hashemian < vahidhashem...@us.ibm.com> wrote: > Hi all, > > We have started a new KIP under > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-70%3A+Revise+Partition+Assignment+Semantics+on+New+Consumer%27s+Subscription+Change > > Your feedback is much appreciated. > > Regards, > Vahid Hashemian > >
