We (they) were playing with this in the THREDDS class, and if I was
keeping up correctly, increasing the size of the MaxPermSize had some
delaying effect in some cases. The delaying effect didn't seem that
significant to me, and wasn't all that predictable from what I saw.
Yeah, the message was restart Tomcat relatively often compared to the
number of reloads, especially if you're on a production server.
John
On Aug 26, 2009, at 8:50 AM, Rich Signell wrote:
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 space this 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
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John Graybeal
Marine Metadata Interoperability Project: http://marinemetadata.org
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