Found the solution: to know which PID to "kill -3" for, use ps -ef --forest to detect the parent thread which has the *most* child threads. Then the thread dump shows in catalina.out.
This is where I found the answer: http://groups-beta.google.com/group/weblogic.developer.interest.performance/ browse_thread/thread/336d16199150720f/40be68d56007a1ea?q=periodic+%22thread+ dumps%22+linux+%22kill+-3%22#40be68d56007a1ea Guillaume > -----Original Message----- > From: Guillaume Lahitette [mailto:[EMAIL PROTECTED] > Sent: 15 March 2005 11:34 > To: Tomcat Users List > Subject: RE: Over 1000 threads running in production > > > Tim, > > Thank you. This is very helpful. > > I've tried kill -3 <pid> (following a google hit: > http://www.findarticles.com/p/articles/mi_m0MLW/is_3_3/ai_11449528 > 1/print) but can't see the thread dump in catalina.out nor > localhost_log....txt files. What did I miss (this is Linux)? > > If you could share your perl / grep / wc scripts, that would > surely jumpstart me and give me some ideas! Thanks in advance. > > Cheers, > Guillaume > > > > -----Original Message----- > > From: Tim Funk [mailto:[EMAIL PROTECTED] > > Sent: 15 March 2005 11:03 > > To: Tomcat Users List > > Subject: Re: Over 1000 threads running in production > > > > > > Take periodic thread dumps and read them. perl, grep, and wc are > > your friends > > to parse the data without going insane. > > > > The thread dumps should give you a general idea of who created them. > > > > -Tim > > > > Guillaume Lahitette wrote: > > > Hello Tomcat'oids, > > > > > > This is Tomcat 4.1.26 on Linux with JDK 1.4.1_03, load balanced > > accross 2 servers by a BigIP device. User base is around 50. > > > > > > Our operations team discovered over 1000 java threads running > > on each production server. It appears that about 20 threads are added > > > to this count every hour. > > > > > > Can someone clarify: > > > a.. how are threads open? Is it 1 thread per HTTP request? > > Can I monitor this / gather more details? > > > b.. how and when are threads "closed"? garbage collected? > > > c.. are threads re-used / pooled? > > > d.. how to tune the number of threads Tomcat uses appropriately? > > > e.. Any known issues with our setup? > > > Any other recommendations, best practices and war stories are > > greatly appreciated! > > > > > > Many thanks in advance. > > > Guillaume > > > > > > > --------------------------------------------------------------------- > > 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]
