Today we celebrate two numbers: 25% lower latency for ATS backend requests at the p75, and up to 1000X reduction of ATS disk read latency at the p999.
Deploying HTTP/2 support to the Wikimedia CDN significantly changed how browsers negotiate and transfer data during the page load process. We found regressions in performance during the transition and are sharing the lessons we learned.
We built an efficient sampling profiler for PHP. It runs continually in production on live requests, and generates trace logs and flame graphs.
WikimediaDebug is a set of tools for debugging and profiling MediaWiki web requests in a production environment. WikimediaDebug can be used through the accompanying browser extension, or from the command-line. This post highlights changes we made to WikimediaDebug over the past year, and explains more generally how its capabilities work.
Looking back at our ups and downs.
Here is how we measure and interpret load times on Wikipedia. Let’s also look at what real-user metrics are, and how percentiles work.