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From: Mike Kienenberger <mkienenb@gmail.com>
Date: Tue, 13 Mar 2012 15:19:01 -0400
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 <CAM1yOjb71uAmapfysiyKr9mQX3MXWanBsJYXOaKzoW8ZK8nQ_Q@mail.gmail.com>
Subject: Re: Memory Usage Problem with Tomcat
To: user@cayenne.apache.org
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If you have almost no activity, why not set up a duplicate environment
running the same version of Tomcat and hit your application  using
JMeter or some other testing tool?

Or perhaps you can get sent the application http access.log file and
duplicate the exact series of requests that generated the problem in
your dev environment.

That said, Tomcat did often seem to have intrinsic memory issues,
which is another reason I stopped using a few years back.

Also, you might want to ask what the exact stacktrace is.   We've had
situations where it was a Tomcat permgen memory issue.   See this
article for details -- there are more details in the comments by
others:

http://www.mkyong.com/tomcat/tomcat-javalangoutofmemoryerror-permgen-space/

Again, a disclaimer as I haven't used Tomcat personally in a while,
although some of my colleagues continue to do so for development.  And
we don't run app servers using it.


On Tue, Mar 13, 2012 at 2:59 PM, Joe Baldwin <jfbaldwin@earthlink.net> wrot=
e:
> OK, I think that I may have run into this before. =A0The ultimate "soluti=
on" was to increase memory - however, I am concerned that may have been a q=
uick-fix and not a long-term fix.
>
> The problem is out of memory errors associated with tomcat heap.
>
> I have a webapp (powered primarily by cayenne). =A0The database has *very=
* little in it. =A0I am essentially serving data (via cayenne & tomcat) and=
 images (via tomcat).
>
> I have a private tomcat instance running on a webhost in a "shared" envir=
onment. =A0What this means is that I *absolutely* cannot attach a profiler.
>
> I am being told by the webhost IT people (who are not always accurate in =
their objectivity) that my app is leaking memory (badly), and that is what =
caused tomcat to crash.
>
> My intuition tells me that with almost no activity on the website (becaus=
e it is not live yet) and Cayenne memory management that I should be able t=
o manage memory well, but it is not the case.
>
> So, if my goal is to determine what the problem is, and if I simply incre=
ase heap size, won't I just be masking a potential problem? =A0i.e. if the =
app runs fine for a while, then mysteriously causes tomcat to run out of he=
ap space, then couldn't there be a memory leak?
>
> If there is a memory leak, and I don't see it on my development server, a=
nd I *can't* use a profiler on my webhost, then how do I get visibility int=
o the memory usage?
>
> Thanks
> Joe
>