2 ms·
I think there's times when using a max makes sense and times when using a percentile makes sense. For measurements that are entirely within my own infrastructu
by philbo 4y ago
I think there's times when using a max makes sense and times when using a percentile makes sense.
For measurements that are entirely within my own infrastructure, I'll always use the max. Outliers there are my responsibility and I want to fix them asap.
For measurements that originate from clients, I'll always use percentiles. There you're measuring the internet, which means people on patchy wifi connections or someone who's train just went through a tunnel. The max will always be spiky and there's nothing you can do about it.
- kqr 4y agoYou may (or may not!) be conflating summary statistics with signal filtering here. For latencies as experienced by interactive users, the tail of the distribution (very high percentiles including maximum) are the summary statistics that matter, period. It sounds like in your case the data is a mixed distribution of both non-actionable garbage and actionable signals, and if you could filter out the actionable, you would benefit from looking at the tail of that distribution. However, the best way you have of filtering out the garbage currently is to filter out the central portion of the mixed distribution. This comes with some false negatives and false positives, and may (or may not!) be the ideal filter in your case. It would be interesting to try to find out!