On the 28th of January 2016 all Wikimedia MediaWiki APIs had 2 short outages. The outage is documented on Wikitech here.
The outage didn’t have much of an impact on most projects hosted by Wikimedia. However due to most Wikidata editing happening through the API, even when using the UI, the project basically stopped for roughly 30 minutes.
Interestingly there is an unusual increase in the edit rate 30 minutes after recovery.
I wonder if this is everything that would have happened in the gap?