Are there any monitoring tools in JRun?

I don't know anything about JRun, but I think that you can use any external profiler tools like the one mentioned in this answer: http://www.jguru.com/faq/viewquestion.jsp?EID=407939.

I personally use OptimizeIt! (www.optimizeit.com) with Tomcat and Resin. The other one mentioned is JProbe (www.jprobe.com)