X-Trace and Andy, sitting in a tree...
Yeah, if I could marry X-Trace, I probably would.
Matei and I worked on X-Tracing Hadoop last year. See the project page here: http://radlab.cs.berkeley.edu/wiki/Projects/X-Trace_on_Hadoop
And right now, I am working with some other X-Trace folks on a CS270 project involving X-Trace graph processing that some of y'all might find interesting. The very earliest version of our project proposal (which will hopefully turn into a full blown project report over the next four weeks) is available for a quick read here: http://docs.google.com/Doc?id=dswvrwj_125hj6fh2dn