Alex, With putAll() on ATOMIC cache all bets are off, for sure.
On Mon, Sep 18, 2017 at 2:53 PM, Alexey Goncharuk < [email protected]> wrote: > 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 <[email protected]>: > > > 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 <[email protected]> > > 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 <[email protected]>: > > > > > > > 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 <[email protected] > > > > > > 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 < > [email protected]> > > > > > wrote: > > > > > > > > > > > Ouch... of course it makes sense for atomic caches. Seems I am > not > > > > fully > > > > > > switched on after weekend =) > > > > > > > > > > > > Agree on other points. > > > > > > > > > > > > --Yakov > > > > > > > > > > > > > > > > > > > > >
