TLDR: The new "Excimer UI" option in WikimediaDebug generates flame graphs on-demand! Open this example to browse a profile I captured earlier from Wikipedia's Main Page.

To learn what this feature is, why we built it, and when you might use it; read this week's post on the Techblog:

https://techblog.wikimedia.org/2023/06/08/flame-graphs-arrive-in-wikimediadebug/ 

If you haven't already, install WikimediaDebug via Firefox Browser Add-ons or Chrome Web Store.

1. Navigate to an article on Wikipedia.

2. Set the widget to "On" with the "Excimer UI" option checked.

3. Reload the page.

A profile link is now appended to the WikimediaDebug popup. Click it!

Excimer can instrument pageviews, edits, search suggestions from the MediaWiki API, JavaScript loading (ResourceLoader load.php), and anything else served by MediaWiki from a WMF domain name—including Commons, Wikidata, and mediawiki.org.

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Timo Tijhof,

Principal Engineer,

Performance Team,

Wikimedia Foundation.