When I asked for tools to profile Rails apps, someone pointed at DTrace. Since I work on MacOSX stations and deploy on OpenSolaris, it is a valid way to go. But I have little kn
This is probably way too late to be useful, but Adam Leventhal's DTrace boot camp presentation is great for getting started:
http://blogs.oracle.com/roller/resources/ahl/dtrace_course.2005.8.18.pdf
You can also try the "dtrace toolkit" it has scripts for lots of monitoring purposes to give you a kick start.
Also you can attach X-Code's "Instruments" to any process. After this gives you a general idea of your app you can give a try to write your own scripts
I did a 35 min video and showed some DTrace starter examples that you can find here: http://cocoasamurai.blogspot.com/2008/05/dtrace-for-cocoa-developers.html which were intended for introducing DTrace to Cocoa Developers, but it can work for anybody really
I found that reading dtrace version of the usual admin monitoring tools of Mac OS X was a great help truss
-> dtruss
. There are at least a dozen different scripts that you can read. (Most begining by "d".)
There also is /Developer/Applications/Instruments.app
which is a graphical app which generates dtrace scripts.
Also, Wikipedia's DTrace page has loads of links which should help.
Watch the Brian Cantrill DTrace video. This is a great demo-based talk and Cantrill is one of the DTrace creators.
http://video.google.com/videoplay?docid=-8002801113289007228