If you are a user of the adds-changes (so-called "incremental") dumps, read
on.
All dumps use database servers in our eqiad data center. For the past
month, the wiki projects have used primary database masters out of our
codfw data center; on one of these days, a number of revisions did not
replicate properly to eqiad for about 50 minutes. This was not discovered
until we switched back to using the database servers in eqiad as primary
masters.
The date that replication was broken was September 13th. Because dumps use
eqiad database servers, the adds-changes dumps published on that date are
also missing that data.
We suggest that if you are using adds-changes dumps for a local mirror, you
import the next regular run of xml/sql dumps, starting on Oct 20th (for
current revisons only) or Nov 1st (for full history), which should contain
the missing revisions.
For more information on this incident, you may follow:
https://phabricator.wikimedia.org/T206743
Ariel