The DNS recursor servers which are used from inside Cloud VPS and Toolforge to resolve both internal and external hostnames to IP address were not functional from approximately 2019-09-09T00:51 UTC to 2019-09-09T01:35 UTC. During this time, most (if not all) DNS lookups would have returned a "SERVFAIL" response. The issue appears to be resolved now.
We will share more information about what happened and how the problem was corrected when we are sure that doing so will not cause additional issues.
Bryan, on behalf of the Cloud VPS admin team
cloud-announce@lists.wikimedia.org