Glossary

Backfill

Trigger skipped jobs (Treeherder terminology). Also refers to filling in missing data points from Perfherder's Graphs view.

Data point

Performance metric value visible in Perfherder's Graph view.

DOM Content Flushed (dcf)

This is a Mozilla proprietary extension and not part of the performance/navigation timing specification. It marks the completion of the first presentation flush after DOMContentLoaded. Internal Firefox metric activated by setting the preference dom.performance.time_to_dom_content_flushed.enabled to true.

Downstream

Alert triggered by a commit that originally happened on another repo and was merged into the current one after.

First Contentful Paint (fcp)

First Contentful Paint (FCP) measures the time from navigation to the time when the browser renders the first bit of content from the DOM.

First Non-Blank Paint (fnbpaint)

The timestamp of a shipped frame that contains the first paint to draw more than the document background. Has low value to a user, as this paint may be completely meaningless or useless. The first non-blank paint is often represented as "Start Render" in performance products.

Gecko profile

Definition needed

mitmproxy

Mitmproxy is a third-party open-source tool (found here in github) that allows the recording of a live web page and saving it as a playback archive. Using Mitmproxy's 'mitmdump' tool, the recorded page can be played back through a local proxy browser proxy; then browsing to the URL loads the page from the mitmproxy recording instead of the live site.

The Raptor performance testing framework uses Mitmproxy for Raptor page-load performance tests. Mitmproxy is available as a python mozbase/mozproxy module for import in any python project.

Noise (regarding performance tests)

Definition needed

Nudge

Definition needed

Perf Sheriff

Definition needed

Perfherder

Definition needed

Raptor

Raptor is a performance testing framework used for running browser page-load and browser benchmark tests. Raptor can run performance tests on Firefox desktop, Firefox android (Fennec, Geckoview example app, and the android components Reference Browser), and Google Chrome/Chromium. For more information please refer to the Raptor wiki page.

RelMan glossary

These terms are of use, especially when doing Performance sheriffing.

Retrigger

Any run of the same job on the same commit for the same repo triggered after the first one. Retriggers usually happen when the available datapoint in the graph are not enough for the sheriff to determine the culprit.

SETA

Definition needed

Talos

Definition needed

Treeherder

Definition needed

Time To First Interactive (ttfi)

Definition needed

R/b

Short name for retrigger/backfill.

WebPageTest

Definition needed