Make BucketedTimeSeries::rate() more accurate
Summary: Make rate() and countRate() more accurate when queried for a specific time range. Previously these functions divided the estimated sum/count by the entire time range specified. This underestimated the rate if we don't actually have data for the entire time period. (Since the sum computed only takes into account the time range for which we have data.) For example, if the timeseries duration was 60 seconds, but only 30 seconds of data had been entered so far, rate(now - 60, now) would underestimate the rate by half, since there was only 30 seconds worth of data available. The no-argument version of rate() did work correctly in that case. Test Plan: Added a new unit test for this behavior. Also fixed the existing rate test code, which had the same bug and expected the underestimated rate. Reviewed By: delong.j@fb.com FB internal diff: D778114
Showing
Please register or sign in to comment