Safety in DTrace

What is one of the best features of DTrace? - that it's production ready. What it means? Well, Bryan Cantrill, one of the DTrace creators, has posted some background information about built-in (or should I write - architectured-in) safety in Dtrace. From my own user perspective, I must admit that this is one of the most important features of DTrace - I can safely use it in a production, and I have actually been doing it for almost 2 years. In practice using DTrace in a production proves to be so safe that I let our developers to use it on a production servers. And why is it so important to use tools like DTrace on a production systems? Well, most pressing problems occur while in a production and during peak hours. If you really want to find your bug quickly, find a bottleneck or some data flow characteristic, etc. you should be doing it at the place were a problem is - production. But you don't want to risk accidentally shutting down your application or entire system during peak hours, don't you? Without all these safety bulit-in DTrace still would be valuable software, but I wouldn't use it in a production so much if at all. When I'm talking to people about DTrace I always start talking about its safety in a first place.