We have a business transaction configured, where we have a result measure which returns us the number of times a certain method has been called. Now we'd like to now how many of these calls were actually slower than 50 ms.
What's the best approach to tackle this?
You can calculate that number on the calculate result section. So you will have a column with slower than 50ms per method. I'm guessing this way you can count those ocurences, with no need to calculate over a calculation...
You're referring here to the result section within the business transaction window, where the result measures are set/created. Not sure how you would do that to accomplish what you are suggesting.
Because or you chose the method invocation, which gives you the number of times it has been called or you chose the method time metrics. Please do elaborate on how you would take only the ones above a certain thresholds into account for the count measure (by preference in one BT).
You can count the events using the method time metrics...Just with the count (response time count) aggregation you will have the number of that method that go beyond 50ms.
Hope this is what you need!