Profiling PHP in production at scale
We built an efficient sampling profiler for PHP. It runs continually in production on live requests, and generates trace logs and flame graphs.
Tag: web performance
Web performance case study: Wikipedia page previews
Preview popups are common and requires careful scripting and styling; they can generate useful learning about performance as a reference for other front-end tasks.
Impact of using HTTP connection pooling for PHP applications at scale
This post explores the challenges of running PHP applications at a large scale and discusses the effect of using Envoy on MediaWiki applications.
Wikimedia’s CDN up to 2018: Varnish and IPSec
The 1st of a 3 part series that will describe some of the changes, which included replacing Varnish with Apache Traffic Server (ATS) as the on-disk HTTP cache component of the CDN.
How we contributed Paint Timing API to WebKit
The story of how we decided to commission the implementation of Paint Timing API, a feature that lets us observe web performance from an end-user perspective. This web browser feature tells us at what point in time content started to appear on the screen for a visitor.
Measuring the performance of Wikipedia visitors’ devices
We have been collecting microbenchmark scores for over a year. This lets us see the long-term evolution of our audience as a whole. The information gives us an idea of how fast device/operating system/browser environments improve on their own.
WikimediaDebug v2 is here!
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.
Wikipedia’s JavaScript initialisation on a budget
This week saw the conclusion of a project that I’ve been shepherding on and off since September of last year. The goal was for the initialisation of our asynchronous JavaScript pipeline (at the time, 36 kilobytes in size) to fit within a budget of 28 KB – the size of two 14 KB bursts of Internet packets.
Tracking down slow event handlers with Event Timing
We’re taking part in the ongoing Event Timing Chrome origin trial, in order to experiment with that API early and give feedback to its designers.
Performance perception: Correlation to RUM metrics
When we set out to ask Wikipedia visitors their opinion of page load performance, our main hope was to answer an age-old question: which RUM metric matters the most to users? And more interestingly, which ones matter the most to our users on our content.