When deploying MediaWiki 1.35.0-wmf.18 to Group 2 wikis on Thursday, there
was a serious incident which took down all wikis for several minutes and
resulted in a rollback to wmf.16.
My current understanding is that attempting to deploy wmf.18 again is
likely to cause another severe outage. The train remains blocked until the
root cause of the outage is identified.
Investigation is ongoing. Details and further updates will be posted on the
status tracking task for wmf.18[1] and some background on the investigation
has been documented in the incident report[2].
[1]
https://phabricator.wikimedia.org/T233866
[2]
https://wikitech.wikimedia.org/wiki/Incident_documentation/20200206-mediawi…