Incident report here: https://wikitech.wikimedia.org/wiki/Incident_documentation/20151022-EventLogging

Basically, select max(timestamp) from any of the tables listed in that incident report returns October 22nd on dbstore1002, and a more recent time on dbstore2002.

There's an additional confusion here because analytics-store seems to refer to two different things in two different places (dbstore1002 and dbstore2002 are both referred to by that name, but data is consumed by WMF from dbstore1002)