JRoller Blows up with Roller 3.1

[Matthew Schmidt]

Hi guys.  Since our upgrade to Roller 3.1, things have not been good in 
the land of JRoller.  The system will occasionally run for a few hours 
and then suddenly add nearly a gig of objects to the heap, all of which 
are instanly pushed to the old gen space and cannot be garbage 
collected.  Restarting the application server does not correct this 
problem, as it often comes right back immediately.  We can see nothing 
in the access logs that are different from when its running fine and 
then its suddenly not.  The search is currenly disabled, so that's not 
causing it. The referer processing is also disabled and our caches in 
Roller are not too large.  We've upgraded both Velocity and Hibernate to 
their latest released versions and that had no effect.  Looking into the 
heap dump, it seems that most of the space is in Strings, probably 
related to Velocity.  We've disabled velocity caching completely right 
now so see if that is the cause. 

Has anyone else seen anything like this?  We're running in a 1.5G heap 
and it just runs normally for a while then flakes out and then won't 
even operate normally after a restart for a while.  Eventually, enough 
restarts get is back into regular operation.  I'd appreciate any help 
you guys can give as without something, JRoller will likely plunge even 
further into dispair.

Thanks,
Matt