On Jul 6, 2012, at 12:44 PM, Mircea Markus wrote:
> ----- Original Message -----
>> From: "Galder Zamarreño" <
galder@redhat.com>
>> To: "infinispan -Dev List" <
infinispan-dev@lists.jboss.org>
>> Sent: Friday, July 6, 2012 2:46:20 AM
>> Subject: Re: [infinispan-dev] singleton @Listeners
>>
>>
>> On Jun 28, 2012, at 11:26 AM, Mircea Markus wrote:
>>
>>> This is a problem that pops up constantly:
>>> User: "I add a listener to my distributed/replicated cache but
>>> this gets invoked numOwners times - can I make that to be invoked
>>> only once cluster wise?"
>>> Developer: "Yes, you can! You have to do that and that..."
>>>
>>> What about a "singleton" attribute on the Listener? Would make the
>>> reply shorter:
>>> Developer: "Use @Listener(singleton=true)"
>>
>> Hmmm, that seems doable without any extra attributes.
>>
>> For a replicated cache, take the view and pick a node (consistently
>>
>> For a distributed cache, find the primary owner of a key.
> That's pretty much how I had in mind to implement it. But I think the attribute is needed though: there are use cases in which you still want to be notified on all the owners, as you do now. OTOH if you only want a per-cluster notification you'd add this attribute to the listener.
>>
>> Has this been asked so often? I don't recall right now… :)
> Yes, CBOE had the same issue as they needed to push updates from one cluster to the other over hotrod.
> Also in this article they have to do quite a workaround to enforce uniqueness:
blog.c2b2.co.uk/2012/06/infinispan-event-push-to-tomcat.html
> And there were some others :)