Hi Ryanne, Thanks for the clarification. I agree that inertia is not a good enough reason to keep MM1 around.
It is a bit weird to be deprecating MM1 in one KIP but proposing to develop it further in another, and that development, if it happened, would undermine the argument that MM2 does everything that MM1 does. We could end up giving people a perverse incentive to stick with, or even adopt, MM1. Doing both these KIPs would be a confusing thing to try to communicate to users. Tom On Fri, Mar 26, 2021 at 5:12 PM Ryanne Dolan <ryannedo...@gmail.com> wrote: > Tom, to clarify, MM2 can definitely replace MM1 in all use cases I've > encountered or can imagine, and many orgs have switched already, e.g. using > IdentityReplicationPolicy aka LegacyReplicationPolicy. Moreover, the > argument of whether to extend or replace MM1 was already decided in > KIP-382. That said, I know that many orgs use MM1 and will probably > continue to do so for a while, and some may never switch. I don't think > that's an argument for keeping MM1 around upstream long-term, and I don't > think anyone is making that argument, so far. I guess I could remove the > phrase "MM1 remains useful" but I specifically wanted to leave room for > KIP-712, which cites MM1 as motivation. (There are definitely plans to > bring the goodness of KIP-712 to MM2, assuming it passes, and I don't want > KIP-720 to jeopardize that.) > > Ryanne > > On Fri, Mar 26, 2021, 11:20 AM Tom Bentley <tbent...@redhat.com> wrote: > > > Hi Ryanne, > > > > With respect, there's a difference between "we still use it because we > > can't be bothered to switch to MM2, or just haven't yet" and "it's > > important for xyz because MM2 doesn't serve our use case properly". While > > the former is not a good reason to argue against deprecation, the latter > > might be, depending on the details. It isn't completely clear to me > whether > > you're asserting that MM2 covers all the same use cases as MM1. On the > one > > hand you don't want to make claims, but on the other you're saying we > have > > MM2 now. An assertion that MM2 addressed all the MM1 use cases would be > > Ismael's explanation about why MM1 is no longer useful, I think. OTOH the > > KIP says it is still useful. So personally I'm confused about which the > > situation is. > > > > Are we deprecating something which for some users MM2 cannot replace? If > > so, I think the KIP should explain clearly why we're intentionally doing > > that. > > > > Kind regards, > > > > Tom > > > > On Fri, Mar 26, 2021 at 3:22 PM Ryanne Dolan <ryannedo...@gmail.com> > > wrote: > > > > > Ismael, I think it is very difficult in general to argue for > deprecation > > -- > > > someone will always say "we still use it" or "it's important for xyz" > -- > > so > > > I don't want to make claims that prompt such responses. The motivation > > for > > > deprecating MM1 is that we now have MM2, and there isn't much else to > > say, > > > IMO. > > > > > > Ryanne > > > > > > On Mon, Mar 22, 2021 at 8:04 AM Ismael Juma <ism...@juma.me.uk> wrote: > > > > > > > I am in favor of this change, but the KIP doesn't include proper > > > > motivation. It says "While the original MirrorMaker remains useful, > we > > > want > > > > to take advantage of the upcoming 3.0 major release to officially > > > deprecate > > > > this legacy code". I would hope we would explain why it's no longer > > > useful > > > > instead. > > > > > > > > Thanks, > > > > Ismael > > > > > > > > On Sat, Mar 20, 2021 at 10:41 AM Ryanne Dolan <ryannedo...@gmail.com > > > > > > wrote: > > > > > > > > > Hey y'all, I'm starting the vote on KIP-720, which proposes to > > > deprecate > > > > > the original MirrorMaker in the upcoming 3.0 major release. > > > > > > > > > > > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-720%3A+Deprecate+MirrorMaker+v1 > > > > > > > > > > Thanks! > > > > > Ryanne > > > > > > > > > > > > > > >
