Re: [thredds] TDS4 Memory settings: PermGen?

• To: THREDDS community <thredds@xxxxxxxxxxxxxxxx>
• Subject: Re: [thredds] TDS4 Memory settings: PermGen?
• From: Rich Signell <rsignell@xxxxxxxx>
• Date: Wed, 26 Aug 2009 11:50:43 -0400

THREDDS Folk

To my chagrin, I just noticed that I asked a PermGen question to
support-thredds just two months ago, and Ethan's reply is here:

http://mailman.unidata.ucar.edu/support/help/MailArchives/thredds/msg01334.html

Basically I guess the message is to not use the "reload" on THREDDS too many
times and to periodically restart Tomcat?

But I'm still wondering whether setting -XX:MaxPermSize=256m in JAVA_OPTS
(up from the default 64m) might help delay the problem (meaning I have to
restart Tomcat less frequently).   I guess I'll find out over the next few
weeks...

-Rich


On Wed, Aug 26, 2009 at 11:27 AM, Rich Signell <rsignell@xxxxxxxx> wrote:

> THREDDS folk,
>
> I see that these is a TDS tutorial updated August 6 at:
>
> http://www.unidata.ucar.edu/Projects/THREDDS/tech/tutorial/index.html
>
> In the section on "Installing Java and Tomcat" I see that it's recommended
> to create a setenv.sh script in the <tomcat>/bin directory with these
> options:
>
> JAVA_OPTS="-Xmx256m -Xms256m -server -Djava.awt.headless=true"
>
>
>
>
> I've noticed that on our TDS4 installations, I often get a "PermGen" error
> which causes tomcat to hang.    On this page:
>
> http://confluence.atlassian.com/display/CONF29/Fix+Out+of+Memory+errors+by+Increasing+Available+Memory#FixOutofMemoryerrorsbyIncreasingAvailableMemory-PermGenSpaceParameters
>
> I read:
>
> Heap space memory errors will contain only a java.lang.OutOfMemoryError.
> If you get the error message: java.lang.OutOfMemoryError: PermGen spacethis 
> means that you have exceeded Java's fixed 64Mb block for loading class
> files. You will need to add the argument -XX:MaxPermSize=256m to
> JAVA_OPTS, in addition to any argument you use to set the heap size.
> PermGen Space Parameters
>
> JAVA_OPTS="-Xms128m -Xmx1024m -XX:MaxPermSize=256m
> -Djava.awt.headless=true "
>
> So I've set this my setenv.sh file for my Tomcat installation to read:
>
> JAVA_OPTS="-Xms128m -Xmx1024m -server -XX:MaxPermSize=256m
> -Djava.awt.headless=true "
>
> I have no idea yet whether this will help, as I just added the MaxPermSize
> parameter today.   Anybody else have experience with PermGen problems
> running TDS4 and know if this should help or how to avoid in the first
> place?
>
> Thanks,
> Rich
> --
> Dr. Richard P. Signell   (508) 457-2229
> USGS, 384 Woods Hole Rd.
> Woods Hole, MA 02543-1598
>
>


-- 
Dr. Richard P. Signell   (508) 457-2229
USGS, 384 Woods Hole Rd.
Woods Hole, MA 02543-1598

• Follow-Ups:
  • Re: [thredds] TDS4 Memory settings: PermGen?
    • From: John Graybeal

• References:
  • [thredds] TDS4 Memory settings: PermGen?
    • From: Rich Signell