Software has evolved tremendously over the past twenty years, but unfortunately the way that we both reason about and measure performance has barely changed. It’s time to stop thinking about software performance as a single number and see it as a shape. In this talk, I’ll present the case for why the industry’s approach to measuring real-time performance needs to evolve from using averages and percentile estimates to unsampled histograms. Latency histograms provide clear visualizations of the statistical modes of production systems and explain variances in performance with greater precision than past approaches. I’ll illustrate this with side-by-side examples of multi-modal histograms and traditional percentile time series statistics.

Daniel “Spoons” Spoonhower is a co-founder at LightStep, where he’s building performance management tools for modern software systems. Previously, Spoons spent almost six years at Google where he worked on developer tools as part of both Google’s internal infrastructure and Cloud Platform teams. He has published papers on the performance of parallel programs, garbage collection, and real-time programming. He has a PhD in programming languages from Carnegie Mellon University but still hasn’t found one he loves.