TL;DR: * c1.labsdb (labsdb1001.eqiad.wmnet) is down due to hardware issues * *.labsdb are pointing to c3.labsdb (labsdb1003.eqiad.wmnet)
The physical server behind c1.labsdb (labsdb1001.eqiad.wmnet) experienced a hard drive failure around 2017-11-01T03:30 UTC. This failure is preventing the MySQL service on that host from starting. The *.labsdb service names that were pointed at that server have been updated to point to c3.labsdb (labsdb1003.eqiad.wmnet) instead.
See https://phabricator.wikimedia.org/T179464 for more information and additional updates.
Expect slower than normal performance as all traffic is handled by a single server. Now would be a great time to update the configuration for your tools to use the new database cluster [0][1].
[0]: https://phabricator.wikimedia.org/phame/post/view/70/new_wiki_replica_server... [1]: https://wikitech.wikimedia.org/wiki/Wiki_Replica_c1_and_c3_shutdown
Bryan