En l'instant précis du 13/06/07 14:35, paul womack s'exprimait en ces termes: > I'm just trying to do some simple profiling > on an app running under tomcat 4. > > I've enabled profiling using: > JAVA_OPTS="-Xrunhprof:cpu=samples,depth=40,thread=y"; export JAVA_OPTS > and am successfully getting a java.hprof.txt file > when tomcat is stopped. (after a 70 second > run, with a perl script hammering away > via http) > > On analysing the file with jperfanal > http://jperfanal.sourceforge.net/JPerfAnal_manual.html > > I was intially completely confused. > > Then I realised than tomcat > is (to say the least) multi-threaded, > and went to use the tool's thread analyses. > > In terms of recorded "ticks", the most important > thread is "main", with 9666 ticks, closely The main thread is the startup tomcat thread. It does various stuff like, i think, responding to shutdown hook, and, most important, starting up your application. It has lots of ticks because the startup of your tomcat is what took you the most time. You should hammer your applicaiton during more than 70 second to have a correct behaviour of cpu usage. initialization stuff from main takes a bit of time (from a few seconds for empty tomcat to 1 or 2 minutes with big applications) but occurs only once per life of jvm.
> followed by: > > TP-processor4 (9470 ticks) > I think they handle various connections of tomcat before dispatching them to http-thread, modjk thread or alike. But not sure. > After this I get a list of > http10722-processor<N> threads, with ticks > running down from 4580 -> 487 > > all other threads have very few "ticks". > > On examining function profiles for these threads, > it is clear that the http threads are actually "my application" > doing useful (IMHO) work. yes, it's the work of application responding to request + time spend by tomcat to parse request and direct it to correct webapplication > > Can anyone outline to me what the main() and TP-processor > threads are doing? > > I'd be happy to be pointed at relevant doc, but I've searched > and read stuff for the last hour without really moving > forward in my understanding. > > BugBear > > > --------------------------------------------------------------------- > To start a new topic, e-mail: users@tomcat.apache.org > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
