Is http://wikitech.wikimedia.org/wiki/EventLogging what you're looking for?

I think that's a good place to start, and to be explicit, from stat1 you can look at the live event logging stream like this:

zsub vanadium.eqiad.wmnet:8600

We wanted to feed this into hadoop at some point to handle larger streams.  So Arthur, let us know if you need that :)