Programs aren’t particularly useful when they can’t tell us things. Programs that say too much can be just as useless as programs that say nothing at all. Programs that say something in the wrong way can cause an undue burden.
“Logging v. Instrumentation” is a story on the last statement above. Logging is great as an event stream of actionable data, but not great for keeping track of the number of requests you had that day. Instrumentation, on the other hand, does a poor job of providing rich actionable event data, but it solves questions about utilization, saturation, and errors on your system fairly well.
There is much more to this argument as you’d imagine. If you monitor systems, I’d recommend considering this argument and solidifying your ideas about when to use logging and when to use instrumentation.