Patrick, many thanks for replying. In my case it wasn't something I was aware of -- the application (from a vendor) implements Spring 2.0's AbstractEntityManagerFactoryBean such that it calls PersistenceProviderImpl.createEntityManagerFactory(String name, String resource, Map m), which seems to use the finalizing broker by default.
I assume that since I ended up with a memory leak, Spring 2.0's cleanup practices are dubious, and the finalizing broker is necessary. So am I correct in guessing that the non-finalizing broker should be the one in the ConcurrentHashMap (with hard references), and the finalizing broker should be in the weak reference set? > -----Original Message----- > From: Patrick Linskey [mailto:[email protected]] > Sent: Wednesday, July 22, 2009 4:58 PM > To: [email protected] > Subject: Re: FW: Memory leak > > Hi, > > Is there any particular reason why you need the finalizing broker? One > (vastly preferable) option would be to use the non-finalizing broker, which, > of course, means that you're promising to close your brokers at the > appropriate lifecycle moments. > > Certainly, the bug deserves to be addressed, as the whole point of the > finalizing mode is to be robust in an environment with dubious cleanup > practices. > > -Patrick > > On Wed, Jul 22, 2009 at 4:15 PM, Russell Collins< > [email protected]> wrote: > > Is there a configuration setting or work around for this in the meantime? > > > > > > Russell Collins > > Sr. Software Engineer > > McLane Advanced Technology > > > > "Do or do not, there is no try." - Yoda > > > > > > -----Original Message----- > > From: David Minor [mailto:[email protected]] > > Sent: Wednesday, July 22, 2009 11:12 AM > > To: [email protected]; [email protected] > > Subject: Re: FW: Memory leak > > > > I've created http://issues.apache.org/jira/browse/OPENJPA-1193 > > > > One thought I had was that the if statement might simply be missing a > > ! -- since this is a concurrency improvement for non-finalizing > > brokers, perhaps the non-finalizing brokers were supposed to be > > switched to the ConcurrentHashMap, rather than the finalizing brokers. > > > > Is Patrick Linskey still involved in openjpa? I haven't seen his name > > for awhile. > > > > > >> -----Original Message----- > >> From: Michael Dick [mailto:[email protected]] > >> Sent: Wednesday, July 22, 2009 6:47 AM > >> To: [email protected]; [email protected] > >> Subject: Re: FW: Memory leak > >> > >> Hi David, > >> > >> At the moment I don't have a ton of free time to dive into the change > >> or the peformance bottleneck that it resolved. In the interest of > >> providing some relief (trunk & 1.3.x) I'd be happy to make this > >> change configurable (maybe something on openjpa.conf.Compatibility) > >> so you can get the old behavior. > >> > >> I've cross posted to d...@openjpa to see if there are any objections. > >> > >> In any event would you mind opening a JIRA issue (I'd do it but then > >> you have to subscribe to get notifications etc.). > >> > >> On Tue, Jul 21, 2009 at 6:37 PM, David Minor <[email protected]> > >> wrote: > >> > >> > Looks like this code was checked in a year ago by Patrick Linskey > >> > with > >> > >> > the comment "Improve concurrency by actively managing > >> > AbstractBrokerFactory's broker set when using non-finalizing brokers. > >> > Credit goes to Arunabh Hazarika for identifying the bottleneck and > >> prototyping this solution." > >> > > >> > I'm not sure why _brokers was changed with regards to > >> > FinalizingBrokerImpl though. BrokerImpl's free() method was > >> > modified to call the factory to remove the it from _brokers. > >> > FinalizingBrokerImpl calls free() from its finalizer, but the > >> > finalizer will never be called if there is a reference in _brokers. > >> > > >> > Anyone have any ideas? > >> > > >> > On Tue, Jul 21, 2009 at 11:24 AM, David Minor <[email protected]> > >> wrote: > >> > > >> > > Hi Mike, > >> > > > >> > > I've tracked the problem down to > >> > > org.apache.openjpa.kernel.AbstractBrokerFactory. The heap dump > >> > > lists > >> > >> > > the _brokers Set as containing all the references to > >> > > FinalizingBrokerImpl, > >> > and > >> > > it appears the assignment of this set was changed to this: > >> > > > >> > > if (FinalizingBrokerImpl.class.isAssignableFrom( > >> > > bv.getTemplateBrokerType(_conf))) { > >> > > return MapBackedSet.decorate(new ConcurrentHashMap(), > >> > > new Object() { }); > >> > > } else { > >> > > return new ConcurrentReferenceHashSet( > >> > > ConcurrentReferenceHashSet.WEAK); > >> > > } > >> > > > >> > > It used to be assigned to the weak reference hash set as in the > >> > > else > >> > >> > > statement. Forcing the second assignment fixes the problem. > >> > > > >> > > > >> > > > > >> > > > -----Original Message----- > >> > > > From: Michael Dick [mailto:[email protected]] > >> > > > Sent: Tuesday, July 14, 2009 7:29 AM > >> > > > To: [email protected] > >> > > > Subject: Re: FW: Memory leak > >> > > > > >> > > > Hi David, > >> > > > > >> > > > There have been a few changes in PersistenceProviderImpl. One > >> > > > was to make the non-finalizing BrokerImpl the default (must be > >> > > > overridden in your > >> > > > config) another that might be interesting was adding a pool of > >> > > > EntityManagerFactories. > >> > > > > >> > > > From what I've seen the EMF pool is not used by default, but > >> > > > it's possible that the AbstractEntityManagerFactoryBean is > >> > > > setting it (the property is named EntityManagerFactoryPool in > >> > > > case that helps). I took a quick pass at setting the pooling > >> > > > property and the only way I saw it take effect was to pass it > >> > > > in as a JVM arg (might be something in my eclipse env though - > >> > > > and I'm on > >> 2.0.0-SNAPSHOT ATM). > >> > > > > >> > > > Hope this gives you a starting point, if not keep replying and > >> > > > we'll > >> > try > >> > > > to help > >> > > > > >> > > > -mike > >> > > > > >> > > > On Mon, Jul 13, 2009 at 8:00 PM, David Minor > >> > > > <[email protected]> > >> > > > wrote: > >> > > > > >> > > >> Hi Mike, > >> > > >> > >> > > >> Nothing else has changed. The application extends spring 2.0's > >> > > >> AbstractEntityManagerFactoryBean class (apparently so that the > >> > > >> persistence.xml file can be named something different). > >> > > >> > >> > > >> I notice it is checking the return type of > >> > > >> AbstractEntityManagerFactoryBean's getPersistenceProvider() > >> > > >> for an instance of openjpa's PersistenceProviderImpl, and > >> > > >> doing something different depending on whether it finds it or > >> > > >> not. Has anything changed with regards to this class? > >> > > >> > >> > > >> > -----Original Message----- > >> > > >> > From: Michael Dick [mailto:[email protected]] > >> > > >> > Sent: Monday, July 13, 2009 12:49 PM > >> > > >> > To: [email protected] > >> > > >> > Subject: Re: Memory leak > >> > > >> > > >> > > >> > Hi David, > >> > > >> > > >> > > >> > FinalizingBrokerImpl will close itself and free resources > >> > > >> > when it's GC'ed. > >> > > >> > It sounds like something else is holding on to a lot of > >> > > >> > references to FBImpl (I'd guess something changed "upstream"). > >> > > >> > > >> > > >> > One cause is if the application creates a large number of > >> > > >> > EntityManagers and doesn't close them (or creates a large > >> > > >> > number of EMFactories which don't get closed since closing > >> > > >> > an EMF will close > >> > > > its EMs). > >> > > >> > > >> > > >> > Did anything else change or did you just upgrade OpenJPA > >> versions? > >> > > >> > > >> > > >> > -mike > >> > > >> > > >> > > >> > On Mon, Jul 13, 2009 at 11:34 AM, David Minor > >> > > >> > <[email protected]> > >> > > >> > wrote: > >> > > >> > > >> > > >> >> Upgrading openjpa from 1.0.1 to 1.2.1 seems to introduce a > >> > > >> >> memory leak > >> > > >> > > >> > > >> >> in our application -- leaving the server running for a few > >> > > >> >> days results in OOM errors (there are quartz tasks making > >> > > >> >> simple openjpa > >> > > > > >> > > >> >> selects during this time). A heap dump reveals > >> > > >> >> org.apache.openjpa.kernel.FinalizingBrokerImpl as the > >> > > >> >> dominant > >> > >> > > >> >> object, > >> > > >> > > >> > > >> >> according to Eclipse's memory analysis plugin. > >> > > >> >> > >> > > >> >> Does anyone have an idea of what might be causing this? > >> > > >> >> > >> > > >> >> -- > >> > > >> >> _____________ > >> > > >> >> David Minor > >> > > >> >> > >> > > >> > > >> > > >> > > >> > > >> > > >> > > >> > > >> > > >> > >> > > >> > >> > > >> > >> > > >> -- > >> > > >> _____________ > >> > > >> David Minor > >> > > >> > >> > > > > >> > > > > >> > > > > >> > > > > >> > > > >> > > > >> > > > >> > > -- > >> > > _____________ > >> > > David Minor > >> > > > >> > > > >> > > >> > > >> > -- > >> > _____________ > >> > David Minor > >> > > >> > >> > >> > >> > > > > > > -- > > _____________ > > David Minor > > > > > > -- > Patrick Linskey > 202 669 5907 > > > > -- _____________ David Minor
