My humble opinion. We need MVCC because it is our way to SQL transactions. SQL is a very important user API (as you might know there is an active work on new SQL engine). Fair SQL transactions is a supplementary and quite needed feature, users ask about it on user list. I believe it is a future of Ignite.
Best regards, Ivan Pavlukhin пт, 7 февр. 2020 г. в 13:23, Seliverstov Igor <gvvinbl...@gmail.com>: > > Note that someone uses it > > Main problem is a recovery process when persistence enabled and a cluster > have more than one node. > > It is a problem even for regular transactional caches, the main difference - > MVCC detects any inconsistencies while regular transactional caches may > ignore it without any notification > > In other cases it works fine and provides promised guaranties. > > Of course there are several minor issues like performance ones, but there is > a plan how to solve them (I could share it if anybody is curious) > > My opinion we should solve consistency issues first and finalize MVCC after > that. > > Until that it’s OK to have it as experimental feature. > > Regards, > Igor > > > 6 февр. 2020 г., в 21:25, Alexei Scherbakov <alexey.scherbak...@gmail.com> > > написал(а): > > > > I'm strongly support removal of MVCC from master. > > > > At the current state it bloats code base and should be reworked from > > scratch using separate code base. > > > > чт, 6 февр. 2020 г. в 19:45, Ilya Kasnacheev <ilya.kasnach...@gmail.com>: > > > >> Hello! > >> > >> Please keep in mind that you need to create a separate proposal voting > >> thread if you really like it to count. I wonder if Dmitry Pavlov can help > >> us with the procedure. > >> > >> Otherwise, I think it makes total sense to restrict MVCC clusters to only > >> have MVCC caches or REPLICATED TRANSACTIONAL caches (are they compatible in > >> our current implementation) and no ATOMIC caches at all. > >> > >> Regards, > >> -- > >> Ilya Kasnacheev > >> > >> > >> чт, 6 февр. 2020 г. в 19:41, Maxim Muzafarov <mmu...@apache.org>: > >> > >>> Ilya, > >>> > >>> > >>> 1. MVCC support requires code maintenance for other developed features > >>> even if has not used and disabled. Currently, we've got an x2 level of > >>> difficulty for implementation of new features. > >>> > >>> 2. It would be much easy to develop and support clusters with > >>> mvcc-caches only rather than have a mixed configuration. With this > >>> option we can dramatically reduce the amount of codebase removing from > >>> mvcc-branch local, atomic, tx caches. > >>> > >>> > >>> So, I'm +1 to remove it from the master branch and mark the current > >>> API with @IgniteExperimental. > >>> > >>> On Thu, 6 Feb 2020 at 19:29, Ilya Kasnacheev <ilya.kasnach...@gmail.com> > >>> wrote: > >>>> > >>>> Hello! > >>>> > >>>> Why would we drop MVCC!? > >>>> > >>>> I can totally imagine a scenario where a large Ignite user surfaces > >> with > >>>> fixes for MVCC mode, if it is kept as an experimental feature. Then > >> maybe > >>>> it will graduate to beta some time in future. > >>>> > >>>> If it does too much strain on the TC, let's discuss that, but I don't > >>>> remember problems with TC load lately, so maybe this is a moot point. > >>>> > >>>> Regards, > >>>> -- > >>>> Ilya Kasnacheev > >>>> > >>>> > >>>> чт, 6 февр. 2020 г. в 15:27, Nikolay Izhikov <nizhi...@apache.org>: > >>>> > >>>>>> By the way, is there any reason to have this code in the master > >>> branch > >>>>> > >>>>> I support removal MVCC from master. > >>>>> > >>>>> > >>>>>> 6 февр. 2020 г., в 15:26, Andrey Gura <ag...@apache.org> > >> написал(а): > >>>>>> > >>>>>> +1 > >>>>>> > >>>>>> By the way, is there any reason to have this code in the master > >>>>>> branch? It seems feature is in unsupportable state and just wastes > >> TC > >>>>>> time and our effort to support MVCC related tests. > >>>>>> > >>>>>> On Thu, Feb 6, 2020 at 2:44 PM Alexey Goncharuk > >>>>>> <alexey.goncha...@gmail.com> wrote: > >>>>>>> > >>>>>>> Agree, let's mark MVCC experimental. > >>>>>>> > >>>>>>> Stephen, the annotation serves as an additional > >> documentation-style > >>>>> marker. > >>>>>>> For now there are no compile-time warnings when the API is used. > >>>>>>> > >>>>>>> чт, 6 февр. 2020 г. в 14:35, Stephen Darlington < > >>>>>>> stephen.darling...@gridgain.com>: > >>>>>>> > >>>>>>>> Yes! I’ve already seen people try to use this without awareness > >>> that > >>>>> it’s > >>>>>>>> not production ready. > >>>>>>>> > >>>>>>>> What happens with the annotation, incidentally? Is it just in the > >>>>>>>> documentation or do you get a compile-time warning? > >>>>>>>> > >>>>>>>>> On 6 Feb 2020, at 11:32, Nikolay Izhikov <nizhi...@apache.org> > >>> wrote: > >>>>>>>>> > >>>>>>>>> Hello, Igniters. > >>>>>>>>> > >>>>>>>>> Should we mark MVCC feature with the new @IgniteExperimental? > >>>>>>>>> > >>>>>>>>> We explicitly note users that MVCC has beta status, for now [1] > >>>>>>>>> > >>>>>>>>>> Beta version of Transactional SQL and MVCC > >>>>>>>>>> In Ignite v2.7, Transactional SQL and MVCC are released as beta > >>>>>>>> versions to allow users to experiment and share feedback. > >>>>>>>>>> This version of Transactional SQL and MVCC should not be > >>> considered > >>>>> for > >>>>>>>> production. > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> [1] > >>>>> https://apacheignite.readme.io/docs/multiversion-concurrency-control > >>>>>>>>> > >>>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>> > >>>>> > >>> > >> > > > > > > -- > > > > Best regards, > > Alexei Scherbakov >
