What are the preffered plugins for monitoring and analyzing the performance of a Rails app? I'm looking for both database/query analyzers and the rest of the stack if possible, though not necessarily all in one plugin. Which ones do you recommend? ( Bonus points for free ones :)
For example, this one looks spify.
This gives info on query analyzers in Rails
http://ronnyml.wordpress.com/2008/07/03/query-analyzer-for-rails/
RAWK I have used to get performance reports emailed to me at regular intervals. It works by analyzing the rails production logs and has always done well for me.
I recently learned about Scout from their article about rails monitoring, but I haven't had a chance to try it out yet, looks promising!
+1 for new relic.
Also consider five runs, I haven't played with it, but it appears to have a loopback mode for development mode, vs's new relics production mode
Derek here from Scout - we've added deep Rails instrumentation as a plugin. This means you'll get a breakdown of where the request time is spent (db,rendering,other) as well as optimization suggestions for slow MySQL queries.
You can play with the instrumentation on our free plan
Screenshot: http://img.skitch.com/20090513-fe4mnaqn5e7i3nsde5qdwrr6k5.png
