Roger, A thread dump/stack trace of all the threads in the Tomcat JVM is one way to see whats happening. It will show what is happening in detail - and may even highlight some problems. It does take a bit of study to understand what you are seeing. Here is an article I use that covers both Windows and *nix: http://java.sun.com/developer/technicalArticles/Programming/Stacktrace/index .html
HTH - Richard > -----Original Message----- > From: Varley, Roger [mailto:[EMAIL PROTECTED] > Sent: Tuesday, December 06, 2005 6:05 AM > To: users@tomcat.apache.org > Subject: Performance problems > > Hi > > We're running Tomcat 4.1.31 under Win NT with 5 individual > web-apps. Most of the time every thing is fine. However, > intermittently the CPU usage of the JVM (java.exe) leaps from > it's normal 4-5% to 70-80% and stays there until we shut down > Tomcat and restart it. The problem is that this jump is > impossible to predict, sometimes we'll see it within a couple > of weeks of a restart, sometimes it will take two to three > months before it happens. I am quite happy to accept that > this is almost certainly an obscure problem within one of the > web-apps rather than a Tomcat error, but I thought that I > would post this on the off chance someone has seen similar > symptoms. Is there a tool/profiler that can be attached to a > running JVM when we see this problem that will let us see the > state of the JVM at the time. > > Regards > Roger > > > ______________________________________________________________ > ____________ > This e-mail and the documents attached are confidential and > intended solely for the addressee; it may also be privileged. > If you receive this e-mail in error, please notify the sender > immediately and destroy it. > As its integrity cannot be secured on the Internet, the Atos > Origin group liability cannot be triggered for the message > content. Although the sender endeavours to maintain a > computer virus-free network, the sender does not warrant that > this transmission is virus-free and will not be liable for > any damages resulting from any virus transmitted. > ______________________________________________________________ > ____________ > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
