I found Lambda Probe for Tomcat a useful tool for fine tuning memory usage. It's free (GPL) and a fairly painless install. http://www.lambdaprobe.org <http://www.lambdaprobe.org/>
Setup tips. To enable memory/processor monitoring you will need to add -Dcom.sun.management.jmxremote to your Java Options, which is easily accessed via Tomat5w.exe tomcat properties tool. When you login in use the username admin and password the same as you use with arsystem web tool. Using the probe I instantly found the default 64mb of memory used up and about 540mb virtual disk in use. I've now given it a 1GB of 4GB and now of course no virtual disk is in use. The only other time I've had memory issues is when testing active links that loop or active links that run on an interval time. The memory errors are so bad that Tomcat crashes. Graham ________________________________ From: Action Request System discussion list(ARSList) [mailto:[EMAIL PROTECTED] On Behalf Of Joe D'Souza Sent: 03 October 2007 21:15 To: arslist@ARSLIST.ORG Subject: Re: Tomcat Using Full CPU on Win2003 I can almost bet I heard somewhere (possibly Remedy Support), a few versions ago (I think during V5 days), that allocating about 4 MB per expected concurrent web user is a fair algorithm to arrive at the expected web server memory usage. I can't see how that might have changed significantly since V5. To be on the safe side I would add another 25% to that figure. Joe D'Souza -----Original Message----- From: Action Request System discussion list(ARSList) [mailto:[EMAIL PROTECTED] Behalf Of Kemes, Lisa Sent: Wednesday, October 03, 2007 12:16 PM To: arslist@ARSLIST.ORG Subject: Re: Tomcat Using Full CPU on Win2003 ** I created a ticket with BMC and they looked at the logs and said that we needed to increase our Java Heap size to 1GB. We have a Windows 2003 Mid Tier server with 2GB of RAM (7.0.1 Patch 3) and there are other apps on this server, so 1GB seemed a little excessive, so I asked "Is there a formula to figure what size the Java Heap should be?" They replied: There is no formula for calculating the heap size. The default heap size on Tomcat is 64mb.Our recommendation to increase the heap size is based on the error we're seeing in the Tomcat log. For large applications such as ITSM 6 we recommend a heap size of 512mb and for larger applications such as ITSM 7, we recommend 1G. Well, we don't have ITSM 6 or 7, just AR System and Mid Tier. We've increased to 128MB so far. But my question is, does anyone have a formula or an idea of what the heap size should be? Also, does anyone have their Tomcat performance or logs monitored to notify when it's over the heap size (when the log says: Java.lang.OutOfMemory: Java Heap Space)? Lisa __20060125_______________________This posting was submitted with HTML in it___ Please consider the environment before printing this e-mail or its attachments. -------------------------------------------------------- This e-mail (and any attachments) contains information, which is confidential and intended solely for the attention and use of the named addressee(s). If you are not the intended recipient you must not copy, distribute or use it for any purpose or disclose the contents to any person. If you have received this e-mail in error, please notify us immediately at [EMAIL PROTECTED] The information contained in this e-mail (and any attachments) is supplied in good faith, but the sender shall not be under any liability in damages or otherwise for any reliance that may be placed upon it by the recipient. Any comments or opinions expressed are those of the originator not of NTT Europe Ltd. unless otherwise expressly stated. NTT Europe Limited is a company registered in England and Wales with company number 2307625. Registered Address: NTT Europe Ltd. 3rd Floor, Devon house, 58-60 St. Katharine's Way, London, E1W 1LB, UK. Telephone +44-20-7977-1000. Facsimile +44-20-7977-1001. Website Link: http://www.ntteurope.com _______________________________________________________________________________ UNSUBSCRIBE or access ARSlist Archives at www.arslist.org ARSlist:"Where the Answers Are"
