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From Erik Engbrecht <erik.engbre...@gmail.com>
Subject Re: Memory usage -> stability probs?
Date Tue, 23 Jun 2009 13:52:41 GMT
Here's a really useful reference:
http://java.sun.com/javase/technologies/hotspot/vmoptions.jsp*

*See the "debugging options" section toward the bottom.

On Tue, Jun 23, 2009 at 9:15 AM, David Pollak <feeder.of.the.bears@gmail.com
> wrote:

> Vassil & Erik -- lots of useful stuff in here... I wish I had know about
> these options when I was debugging the Actors memory retention problems...
> :-)
>
> On Tue, Jun 23, 2009 at 4:36 AM, Erik Engbrecht <erik.engbrecht@gmail.com
> >wrote:
>
> > -XX:+*HeapDumpOnOutOfMemoryError** **is also very useful for
> post-mortems.*
> >
> > On Tue, Jun 23, 2009 at 2:46 AM, Vassil Dichev <vdichev@apache.org>
> wrote:
> >
> > > > I added code that will dump memory information every 10 minutes.
> >  Please
> > > put
> > > > the new code live.  If it barfs, please send me the output (privately
> > is
> > > > better so we don't spam the list with a 10MB file)
> > > > I'm running an instance on my local box and will see if I can find
> > memory
> > > > leaks.
> > >
> > > This is cool, but I'm afraid we might need some extra info from the
> > > JVM. I'm not sure you can change the command-line or environment you
> > > use to start the application in Stax, but this should display detailed
> > > information for the Sun JVM.
> > >
> > > MAVEN_OPTS=-verbose:gc -XX:+PrintGCDetails -XX:+PrintClassHistogram
> > >
> > > and for extra debugging, you can turn on the built in profiler with
> > > the following options:
> > >
> > > -Xrunhprof:heap=sites,cpu=samples,doe=y
> > >
> > > It will make the JVM run even slower, but could really pinpoint where
> > > the problem was.
> > >
> > > As for thread dumps, they're even more useful if you encounter the
> > > 100% CPU issue, but we need to send a signal to the JVM, which I'm not
> > > sure you can do at all in a managed stax environment. There are
> > > solutions to trigger it programmatically, but you need to include a
> > > native library, which is another restriction we might not be able to
> > > overcome.
> > >
> > > All in all, it would be much better if we can reproduce it locally,
> > > where we can play with the application. I assume you couldn't set
> > > MAVEN_OPTS last time there was a problem, since there was no feedback.
> > > Monitoring an app for memory problems in a restricted environment is
> > > notoriously hard.
> > >
> > > Vassil
> > >
> >
> >
> >
> > --
> > http://erikengbrecht.blogspot.com/
> >
>
>
>
> --
> Lift, the simply functional web framework http://liftweb.net
> Beginning Scala http://www.apress.com/book/view/1430219890
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> Git some: http://github.com/dpp
>



-- 
http://erikengbrecht.blogspot.com/

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