Microservices require distributed debugging; distributed debugging requires distributed tracing. Just imagine, as I've been trying to push forwards in my own Ph.D. work, that you could debug a process across microservices. This is why we want this; possibly, done a bit more resiliently and thoroughly than the original OP.
…or, I guess Barbara Liskov in 1987, with Argus. And yet, we still seem to debug programs interactively in isolation. Perhaps it’s because all of those systems assumed a system developed in isolation, that didn’t evolve independently and weren’t implemented in different programming languages communicating through different network protocols instead of function/method invocations.
