Following on from I4f653bba, since the schema and statsvInstrumentation
modules are similar, let's group/rename them:
schema -> instrumentation/eventLogging
statsvInstrumentation -> instrumentation/statsv
Change-Id: Ic59e0da7d4917f6733fd090f15d3c269af863f05
... from the statsvInstrumentation module so that the bucketing logic
can be shared with other instrumentation modules.
Change-Id: I5732fa539a3911939fa85fa88c102fa8dcfa5613
The setup and teardown hooks on QUnit.module are deprecated on the
latest versions.
See https://api.qunitjs.com/QUnit/module
mw-node-qunit supports them but we shouldn't be using them.
Bug: T160406
Change-Id: I32c07f22d01d16449a6e37f46ff20c577a1f14c6
For logging to work:
1. $wgWMEStatsdBaseUri needs to point to a valid statsv endpoint,
e.g. 'https://en.wikipedia.org/beacon/statsv'.
2. $wgPopupsStatsvSamplingRate needs to be set. Note that the codebase
already contains the EventLogging functionality, which is configured
separately. Separately configuring different logging mechanisms
allows us to avoid sampling mistakes that may arise while choosing
one or the other. For example, let's say we want to use EventLogging for
10% of users and statsv for 5%. We'd sample all users into two
buckets: 50/50. And then we'd have to set the sampling rates as
20% and 10% respectively, only because of the bucketing above. To avoid
this kind of complications, separate sampling rates are used for each
logging mechanism. This, of course, may result in situations where a
session is logged via both EventLogging and statsv.
3. The WikimediaEvents extension needs to be installed. The extension
adds the `ext.wikimediaEvents` module to the output page. The
logging functionality is delegated to this module.
Notable changes:
* The FETCH_START and FETCH_END actions are converted to a timed action.
* The experiments stub used in tests has been extracted to the stubs
file.
Logged data is visualized at
https://grafana.wikimedia.org/dashboard/db/reading-web-page-previews
Bug: T157111
Change-Id: If3f1a06f1f623e8e625b6c30a48b7f5aa9de24db
