Once the session tick instrument https://gerrit.wikimedia.org/r/c/mediawiki/extensions/WikimediaEvents/+/619479 is merged in we want to activate it on an initial set of wikis (via stream configuration) on the beta cluster for testing. This involves adding the appropriate entries in wmf-config/InitialiseSettings-labs.php:

• deploymentwiki
• testwiki

Then later we can roll it out on, say, hawwiki (Hawaiian Wikipedia) in production via wmf-config/InitialiseSettings.php.

And by then we'll have sampling configs and can deploy to all wikis via 'default' but set it to sample 0.01% sessions (for example).