In T180036: Instrument time to first user link interaction, we added an additional piece of data to every event sent by the EventLogging instrumentation that would allow us to identify the typical time to first link interaction on a page, accurate to less than 1 ms. We did this because the timestamps available to us from the server-side were only accurate to the second (see T179426#3741809 onwards).
In T178500: Stop sending data for Page Previews enwiki and dewiki A/B test (again), the EventLogging instrumentation was disabled. Obviously, we need to enable it.
- This is as simple as setting $wgPopupsEventLogging = true in the config for English and German Wikipedia only.
- The logging should be disabled eight days after enabling it. (We want to collect a full week's worth of data, allowing, as last time, an additional day for the initial change to propagate.)
- Notify Analytics Engineering of the date and time that the instrumentation was enabled so that they can drop data that they've already collected with broken timestamps (see T182000: Popups timestamp field contains multiple types for more detail).
Done in T181493#3830489.