We print the rand seed and allow tests to take a set seed. This allows us to use random generated data and still have deterministic results for reproducing failed cases.
Yep, this is a really useful approach, and I highly recommend anyone here who is thinking of trying this stuff out to take a note of the seed (or ensure it's printed) as the first time you realise you want to do this it's often too late!
I've used the same technique when running randomly generated traffic when testing telecom systems. Very useful to be able to re-run the same random sequence!
