Hi List,
We have been pushing our application with some performance testing of late and during these tests we are experiencing some PermGen out-of-memory problems using JRuby 1.2.0 + Rails 2.2.2. Our application is a multithreaded app, a main thread with a number of worker threads. The worker threads are fairly simple really, mainly making use of ActiveRecord libraries, then we simply let them die.
For our testing we have increased the heap size and only now are we encountering a PermGen problem. I have read the article by Nick Sieger (
http://blog.nicksieger.com/articles/2008/02/21/jruby-and-the-permanent-generation) but what isn't clear is how to estimate the required PermGen size, when is enough enough? Is there a reason why we are only encountering the problem after increasing the heap size?
We as yet have not changed the default PermGen sizes so they are as
default (64m max?) as we want to understand what is going on before we
start increasing things across the board.
I guess my question boils down to a few things:
1/ Do we have a problem? A leak? What is a good stratery for detecting this leak? Or is it a known problem solved with a larger PermGen space?
2/ If more PermGen space is the answer how can we estimate the requirements?
Any info would be great,
Cheers,
Mik.
