[infinispan-dev] Translating our events to JSR 107 events

[Manik Surtani]

>>>> 
>>>> > The second I have no idea how to implement as we do not have
>>>> > CacheEntryExpired event. True, spec is not rigorous that such an event
>>>> > has to be fired immediately after an entry has expired but eventually
>>>> > (which might be on access). Either way, I am all ears on suggestions how
>>>> > to implement this one.
>>>> >
>>>> 
>>>> I guess @CacheEntryEvicted/@CacheEntriesEvicted would be the closest thing we have in Infinispan. But you can't check in the listener if the entry was evicted because it expired or because there wasn't enough space in the data container (yet).
>>> There could definitely be something clever we could do here.  Adding the (expired or evicted) entry to a queue for later notification.  But that would definitely need to be something we explicitly enable rather than have running all the time, since it kinda defeats the purpose of evicting something to save memory only to have it put in a different queue elsewhere until an event is fired.
>> 
>> Exactly! One thing we could do is what RI does. Check for expired on entry access from JSR module and during normal expired cleanup cycle..... 
> 
> Be mindful of performance considerations here - this could get very expensive.
> 
> 
> Exactly. I don't think you can use a queue for later notification, because you also have to cancel the notification if the user updates the same key again. I mean if an entry was supposed to expire at 12:00 and the user did a put at 12:59 with expiration time 12:30, then he shouldn't get an expired notification at 12:00 - even if the entry was evicted in the meantime.


Yes; definitely not a simple thing to do.
--
Manik Surtani
manik at jboss.org
twitter.com/maniksurtani

Platform Architect, JBoss Data Grid
http://red.ht/data-grid

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