So, to be fair to the xray people, what they have done meets a very specific set of use cases you can't meet with most other tracing tools (I haven't looked at

So, to be fair to the xray people, what they have done meets a very specific set of use cases you can't meet with most other tracing tools (I haven't looked at dtrace hard enough. at a glance, it looks like it would not meet several things, but dtrace is not a sane option for them for a variety of reasons). Past that, the mechanism used to do this, and the system itself, is not uncommon to build. I don't see any claims that say they think they've broken new ground. Just that they built it :)