users@glassfish.java.net

Re: Endless growing and shrinking heap

From: Ryan de Laplante <ryan_at_ijws.com>
Date: Thu, 06 Nov 2008 10:26:22 -0500

This might be normal since the same thing is happening on my dev box
GlassFish


Ryan de Laplante wrote:
> Hi,
>
> I have attached a few screenshots that show some disturbing behavior.
> I'm trying to investigate why our app server (SJSAS 9.1 UR2) ran out
> of heap space twice, exactly two weeks apart. The first screenshot
> shows that the used heap grows linearly until it hits the maximum,
> then is garbage collected? The second screenshot shows Timer threads
> being created and destroyed a few seconds later endlessly. That
> might explain why the heap dump I took during the last "out of heap
> space" error was only 122 MB when the max heap was set to 512 MB at
> the time.
>
> The third screenshot shows that my application has many timers, but
> each of them have a name. So, I know that the timers being created
> endlessly are not my own timers.
>
> I have changed the -Xmx setting in domain.xml and restarted:
>
> <jvm-options>-Xmx1024m</jvm-options>
>
> There were two places that listed JVM options so I changed them both.
> The graph in VisualVM shows the heap maxing out around 500 MB so it
> looks like that option didn't take effect.
>
> Presently the Windows 2003 Server task manager says the java.exe
> process is using "589,148 K". I read that as 575 MB.
>
>
> Thanks,
> Ryan