Re: [infinispan-dev] ISPN-232 - feedback needed

On 25 May 2010, at 15:09, Mircea Markus wrote: > > On 25 May 2010, at 16:26, Manik Surtani wrote: > >> >> On 25 May 2010, at 14:15, Mircea Markus wrote: >> >>>>> >>>>> But, I'd be concerned about an Infinispan thread that's needed >>>>> for doing a lot of critical work during a view change getting tied up >>>>> making a ton of notifications. >>>> >>>> ^^ Yeah that's my concern. If during a rehash we need to stop at every entry that is being moved and issue a notification, that could be costly and really slow down the rehashing process. >>> Can't we register an *async* notification listener on ViewChanged ? >> >> You'd still have a *lot* of notifications being queued up for the notification executor since you will have 1 event *per entry* that is moved. > this would still happen in the same JVM as this information is needed. Just that we offer this as a service, so that users(AS being one of them) won't have to write this code. No, if the AS does it, it will be one notification (view change) + a scan of known session ids (keys). If we do it, it will involve 1 notification *per key* being migrated.

The cost of each notification is the construction and initialization of an event object - which includes cloning the invocation context - and placing it on an executor queue. >> Could be thousands, tens of thousands in cases. >> All other notifications will be severely delayed (depending on your async notifier executor threadpool size) > If you have an big enough thread pool (actually at least 2 threads) this should be no issue - and this should be made clear to the user. Executor queue size? This could start blocking? >> >> >> -- >> Manik Surtani >> manik(a)jboss.org >> Lead, Infinispan >> Lead, JBoss Cache >> http://www.infinispan.org >> http://www.jbosscache.org >> >> >> >> >> >> _______________________________________________ >> infinispan-dev mailing list >> infinispan-dev(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/infinispan-dev > > > _______________________________________________ > infinispan-dev mailing list > infinispan-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/infinispan-dev -- Manik Surtani manik(a)jboss.org Lead, Infinispan Lead, JBoss Cache http://www.infinispan.org http://www.jbosscache.org _______________________________________________ infinispan-dev mailing list infinispan-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/infinispan-dev