Comment by kiitos

> Tracing every http 200 at 10k req/sec is not something you should be doing

You don't know if a request is HTTP 200 or HTTP 500 until it ends, so you have to at least collect trace data for every request as it executes. You can decide whether or not to emit trace data for a request based on its ultimate response code, but emission is gonna be out-of-band of the request lifecycle, and (in any reasonable implementation) amortized such that you really shouldn't need to care about sampling based on outcome. That is, the cost of collection is >> the cost of emission.

If your tracing system can't handle 100% of your traffic, that's a problem in that system; it's definitely not any kind of universal truth... !