The mission of Wikimedia Performance is for our sites to transcend socioeconomic barriers around reliable and fast access to find and contribute knowledge. We provide tools and expertise to empower developers, and directly inform or undertake high-yield engineering projects. [1][2]
The below is a periodic introduction and summary of recent changes to our guides. If you haven't read these before, or if it's been more than six months, I recommend taking a fresh look. Especially if you work on frontend or backend components in a MediaWiki extension or MediaWiki core.
== Current best practices ==
The practices guides help set direction. Use them to guide new developments, or to identify areas for improvement in current code. If you're short on time, focus on the "Getting started" section atop each guide.
* The introduction details the principles that drive our platform's architecture, and how to get the most out of it.
* Changed: The CSS "@embed" optimisation is now only recommended for very small icons (up to 0.3KB). The guide explains why and how.
* New "Getting started" section, with pointers to specific chapters for detailed guidance.
* Rewritten "Shared resources" chapter, now with a more accessible explanation of MySQL deadlocks and how to avoid them.
* Update "Multi-datacenter deployment" guidance. (No changes are needed to existing code.) We first adopted Multi-DC practices in 2015. WANObjectCache and JobQueue interfaces have gotten simpler since. Cross-DC purges and job queuing "just work", with no awareness or responsibility on calling code. MediaWiki now automatically pins a browser to the primary DC for a few seconds after publishing an edit. This allowed us to remove cross-DC complexity around the
ChronologyProtector.
== Measuring ==
The new "measure" guides help assess performance of existing code, and can help iterate development of proposed changes.
Frontend includes browser dev tools and continuous monitoring through dedicated perf testing infrastructure:
Backend includes flame graphs, benchmarking, and automatic Grafana stats if you adopt WANObjectCache:
== More ==
The above guides and an overview of datasets, tools, recommended Grafana dashboards, and infrastructure diagrams are available at:
On behalf of the Performance Team,
-- Timo Tijhof.