> When there are no tall tent poles I switch to invocation count Oh, yes! It's so useful to keep an eye on invocation counts. For example, one "problematic" s

> When there are no tall tent poles I switch to invocation count Oh, yes! It's so useful to keep an eye on invocation counts. For example, one "problematic" service in a team I managed was being analyzed by an engineer on my team. He was focused on % time culprits, but I spied a highly suspicious entry a fair ways down the list taking many, many orders of magnitude more invocations than anything else. Off I went to have a look... It turns out the original dev had meant to put a blocking call in in the code, but had gotten mixed up and used a polling version instead. (Both were non-obviously named and signature interchangeable. Sigh.) The baseline CPU hit in the perf run wasn't significant, but in context of this service, it produced a very severe performance cliff characteristic under high site load. A one-line change corrected that error, and suddenly the operations team stopped talking about that service (with evil glares ;-) at every opportunity.