Background

Readers Web have run numerous A/B tests for Page Previews and will be reporting their results as part of T182315: Write and publish report on enwiki and dewiki a/b test analysis for page previews. The EventLogging instrumentation may have been the cheapest way to record the new "page interactions" metric but has was discarded as a solution while discussing T182414: [Spike] How can we measure seen page previews with as high a degree of accuracy as possible? (see the notes).

The A/B testing code EventLogging instrumentation is now redundant and only increases the size and complexity of the codebase.

AC

• The A/B testing code is removed from the codebase.t
• The EventLogging instrumentation is removed from the codebase.
• The configuration is tidied up:
  • $wgPopupsAnonsExperimentalGroupSize is removed.
  • …