Today we switched MediaWiki from our eqiad datacenter to codfw. In total
there was 1 minute 57 seconds of read-only time, which is basically what
we were aiming for.
We really only had one user-facing issue in that tr.wikivoyage.org
inaccessible for a few minutes because of a typo.
<https://phabricator.wikimedia.org/T260297> tracks making sure it
doesn't happen again.
Other than that, there's not much to report, it went pretty smoothly.
The rest of the bugs/issues filed as a result of today's switchover are
at <https://phabricator.wikimedia.org/T281515#7185775>, most are related
to improving the automation around the switch itself.
We've noticed that MediaWiki in codfw is slightly faster, most likely
because of newer hardware. Now that eqiad isn't serving traffic, we plan
on installing new hardware there too:
Thanks to everyone who participated in today's switchover and for all
the efforts and work ahead of time to make today so smooth.
We will be switching back to eqiad sometime in August, more details to
come as we get closer.