yes pls follow leon's advice and compare your thread dumps so you can determine TC thread activity and coordinate that to the webapp's resource activity
I would look at minHeap, maxHeap and stack parameters from %JAVA_OPTS% a 2004 post http://forums.sun.com/thread.jspa?messageID=10055131 says it best The default stack size is 256K on UNIX and on 32-bit Windows operating systems. To set Stack size java -XX:NewSize=128m -XX:MaxNewSize=128m -XX:SurvivorRatio=8 -Xms512m -Xmx512m 1. Setting the New generation heap size -XX:NewSize Use this option to set the New generation Java heap size. Set this value to a multiple of 1024 that is greater than 1MB. As a general rule, set -XX:NewSize to be one-fourth the size of the maximum heap size. Increase the value of this option for larger numbers of short-lived objects. Be sure to increase the New generation as you increase the number of processors. Memory allocation can be parallel, but garbage collection is not parallel. 2. Setting the maximum New generation heap size -XX:MaxNewSize Use this option to set the maximum New generation Java heap size. Set this value to a multiple of 1024 that is greater than 1MB. 3. Setting New heap size ratios -XX:SurvivorRatio The New generation area is divided into three sub-areas: Eden, and two survivor spaces that are equal in size. Use the -XX:SurvivorRatio=X option to configure the ratio of the Eden/survivor space size. Try setting this value to 8, and then monitor your garbage collection. 4. Setting minimum heap size -Xms Use this option to set the minimum size of the memory allocation pool. Set this value to a multiple of 1024 that is greater than 1MB. As a general rule, set minimum heap size (-Xms) equal to the maximum heap size (-Xmx) to minimize garbage collections. 5. Setting maximum heap size -Xmx Use this option to set the maximum Java heap size. Set this value to a multiple of 1024 that is greater than 1MB. pay attention to MaxHeap, MinHeap, StackSize and set your GC's to mark and sweep for discarded blocks HTH Martin Gainty ______________________________________________ Disclaimer and confidentiality note Everything in this e-mail and any attachments relates to the official business of Sender. This transmission is of a confidential nature and Sender does not endorse distribution to any party other than intended recipient. Sender does not necessarily endorse content contained within this transmission. > Subject: CPU utilization and Tomcat 5.5.20 > Date: Fri, 3 Oct 2008 14:29:23 -0500 > From: [EMAIL PROTECTED] > To: users@tomcat.apache.org > > We are running Tomcat 5.5.20 with jvm 1.5.0_14. Tomcat utilization goes > to 100 percent being used by Tomcat. Any ideas why the utilization would > go so high. Thanks. _________________________________________________________________ Want to do more with Windows Live? Learn “10 hidden secrets” from Jamie. http://windowslive.com/connect/post/jamiethomson.spaces.live.com-Blog-cns!550F681DAD532637!5295.entry?ocid=TXT_TAGLM_WL_domore_092008
