Re: Debugging my Connector/J based Tomcat Servlet

Op vrijdag, 10 juli 2009 18:08 schreef Niklas Saers <[email protected]>:
> 
> On Jul 10, 2009, at 5:29 PM, Simon Ohlmer wrote:
> 
> > Sorry for asking more questions but what is the version of the JVM/ > Tomcat? Do you run System.gc() at the finish of the servlet  
> > execution? Have you monitored the amount of times the gc is  
> > executing (memmory graph)?
> 
> No problem at all. :-)  Java 1.5.0 with Tomcat 5.0.something (don't  
> remember just now). I don't run System.gc() ever, I let the servlet do  
> that. How should I monitor the amount of times the GC runs?
> 
> Cheers
> 
>     Nik
> 
>  

Get the pid of the Tomcat process with jps. Tomcat is called BootStrap in that list, because that is the name of the main-class of Tomcat. Than run this command. Substitude the pid for <pid>.
jstat -gc -h 10 -t <pid> 10s

The column FGC (I think) shows the number of Full GC's that happened. The column OC and OU show the Old Capacity and Old Use and that is probably where your classes are in.

Greetings,

Ronald.