Vladimir,
I doubt it will be possible to add any meaningful guarantees to ATOMIC
caches with MVCC. Consider a case when a user does a putAll, not a single
put. In this case, updates received by multiple primary nodes are not
connected in any way. Moreover, whenever a primary node fails, the put for
failed keys will be re-tried, which will lead to all sorts of overlapping
updates in case of parallel putAll. It is hard to suggest how we should
handle this, let alone explain this to a user.
-- AG
2017-09-18 14:50 GMT+03:00 Vladimir Ozerov <voze...@gridgain.com>:
> Yakov,
>
> I would say that my example is not about adding transactions to ATOMIC
> cache, but rather about adding consistent snapshots to it.
>
> On Mon, Sep 18, 2017 at 1:59 PM, Yakov Zhdanov <yzhda...@apache.org>
> wrote:
>
> > Vladimir, I think we can ask user to switch to transactional cache to
> > support your example. Otherwise, it seems we are turning atomic caches to
> > tx implicitly.
> >
> > --Yakov
> >
> > 2017-09-18 13:49 GMT+03:00 Vladimir Ozerov <voze...@gridgain.com>:
> >
> > > Semen,
> > >
> > > Consider use case of some audit table where I log user actions over
> time.
> > > Every actions is a put to ATOMIC cache. User interacts with my
> > application,
> > > and performs the following set of actions:
> > > 1. 08:00 MSK -> LOGIN
> > > 2. 08:10 MSK -> Update something
> > > 3. 08:20 MSK -> LOGUT
> > >
> > > If MVCC is there, whenever I query all actions performed by the user, I
> > > would see either {}, {1}, {1, 2} or {1, 2, 3}
> > > Without MVCC I can see weird things, such as {1, 3} or {2}, or
> > whatsoever.
> > >
> > > Vladimir.
> > >
> > >
> > > On Mon, Sep 18, 2017 at 1:41 PM, Semyon Boikov <sboi...@gridgain.com>
> > > wrote:
> > >
> > > > Guys,
> > > >
> > > > I do not really understand mvcc for atomic cache, could you please
> > > provide
> > > > some real use case.
> > > >
> > > > Thank you
> > > >
> > > > On Mon, Sep 18, 2017 at 1:37 PM, Yakov Zhdanov <yzhda...@apache.org>
> > > > wrote:
> > > >
> > > > > Ouch... of course it makes sense for atomic caches. Seems I am not
> > > fully
> > > > > switched on after weekend =)
> > > > >
> > > > > Agree on other points.
> > > > >
> > > > > --Yakov
> > > > >
> > > >
> > >
> >
>
