Dmitriy,
Here, by "stateless" I meant whatever Alexey meant in his previous post in this
thread. But I'm really talking about being able to have EPs with side effects
and therefore the execution semantics should be "exactly-once" by default.
Besides, maybe it's just me, but intuitively the expectation of Cache.invoke()
is that the EP will be executed only once because *logically* there can only be
one entry with the given key in the cache to which the EP is applied. Having
the EP executed many times for the same entry comes as a big surprise, at least
to me.
Maybe it's worth considering an API similar to what Hazelcast has to make it
possible to explicitly control EP's execution semantics.
Regards
Andrey
> From: dsetrak...@apache.org
> Date: Mon, 30 Nov 2015 23:16:58 -0800
> Subject: Re: EntryProcessor execution semantics
> To: dev@ignite.apache.org
>
> On Mon, Nov 30, 2015 at 9:02 AM, Andrey Kornev <andrewkor...@hotmail.com>
> wrote:
>
> >
> > Neither Coherence nor Hazelcast require the EP to be stateless and
> > side-effect free. Even better Hazelcast makes the choice explicit by
> > providing the backup aware processor API and it's then up to the user to
> > ensure statelessness etc. But Ignite is just too clever.
> >
>
> Andrey, stateful EP seems a bit utopian to me, since the state would not
> survive between executions anyway. Can you elaborate?
