Kevin Sutter commented on OPENJPA-115:

Thanks, Patrick and Craig.  I did some looking in lib and found that we also 
have a ConcurrentReferenceHashSet.  So, I have modified _brokers accordingly 
and am waiting for our test results.  I have also removed the explicit 
lock/unlock invocations.  As Patrick pointed out, the findBroker() is never 
called since findExisting is always false for OpenJPA, thus the other synch 
block shouldn't come into play.  Hopefully, with the weak references in 
ConcurrentReferenceHashSet _brokers, this should help with the blocking and 
broker cleanup.  Our original experimentation showed that even with the weak 
references in ReferenceHashSet, we still bogged down during the cleanup of the 
_brokers collection.  But, maybe there's a problem with SunOne where they are 
not properly closing the EntityManagers.  I'll post back when we get the test 

> Bottleneck(s) with using OpenJPA in a Container-managed environment
> -------------------------------------------------------------------
>                 Key: OPENJPA-115
>                 URL: https://issues.apache.org/jira/browse/OPENJPA-115
>             Project: OpenJPA
>          Issue Type: Bug
>          Components: kernel
>            Reporter: Kevin Sutter
>         Assigned To: Kevin Sutter
>            Priority: Critical
> Running some benchmarks against OpenJPA using the Sun Java System (SunOne) 
> application server.  Under load, we're not able to push the cpu to 100%.  The 
> culprit seems to be the lock and synchronization processing within 
> AbstractBrokerFactory.newBroker(..).  According to sections 5.9.1 and 5.9.2 
> in the JPA specification, it looks like OpenJPA is attempting to do too much 
> management of the created EntityManagers.  Within a Container-managed 
> environment, the Container takes care of the lifecycle of the EntityManagers. 
>  So, there does not seem to be a need to do the findBroker(..) invocation, 
> nor is there a need to keep track of the created EntityManagers (_brokers) so 
> that they can be closed when the Factory is closed.
> Once we have verified these changes, there may be others that are needed.  
> But, we have to get by this bottleneck first before going to the next layer...
> Kevin

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