Thanks Sönke for the feedback. I debated this point quite a bit before deciding to base creation around "min.insync.replicas".
For me, the goal of this KIP is to enable administrators to provide higher availability. In a 3 node cluster configured for high availability (3 replicas, 2 min ISR), by enabling this feature, clusters should be fully usable even when 1 broker is down. This should cover all "normal" maintenance operations like a rolling restart or just the recovery of a broker. At the moment, when creating a topic/partition, the assumption is that the resource will be fully functioning. This KIP does not change this assumption. If this is something someone wants, I think it should be handled in a different KIP that targets that use case. By relying on "min.insync.replicas", we don't break any assumptions the user has and this should be fully transparent from the user point of view. About "min.insync.replicas", one caveat that is not explicit in the KIP is that it's currently possible to create topics with less replicas than this settings. For that reason, I think the implementation will actually rely on min(replicas, min-isr) instead of simply min.insync.replicas. I have updated the KIP to explicitly mention this point. I hope that answers your question, let me know. Thanks On Mon, Dec 16, 2019 at 4:38 PM Sönke Liebau <soenke.lie...@opencore.com.invalid> wrote: > > Hi Michael, > > that sounds like a useful addition! I can't help but wonder whether by > leaving in the restriction that "min.insync.replicas" has to be > satisfied we'll be back here in a years time because someone has a > scenario where he or she wants to go below that :) > I don't have a strong opinion either way to be honest, just a random > thought when reading the KIP. > > Best regards, > Sönke > > On Thu, 12 Dec 2019 at 22:44, Ryanne Dolan <ryannedo...@gmail.com> wrote: > > > > +1 non-binding, thx > > > > On Thu, Dec 12, 2019 at 6:09 AM Mickael Maison <mickael.mai...@gmail.com> > > wrote: > > > > > Bumping this thread, I've not seen any votes or feedback. > > > > > > On Wed, Nov 13, 2019 at 12:17 PM Mickael Maison > > > <mickael.mai...@gmail.com> wrote: > > > > > > > > Hi all, > > > > > > > > I'd like to start a vote on KIP-409: Allow creating under-replicated > > > > topics and partitions > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-409%3A+Allow+creating+under-replicated+topics+and+partitions > > > > > > > > Thanks > > > > > > > -- > Sönke Liebau > Partner > Tel. +49 179 7940878 > OpenCore GmbH & Co. KG - Thomas-Mann-Straße 8 - 22880 Wedel - Germany
