Dear Wikitechians,
On *Wednesday March 1st*, the SRE team will run a planned data center
switchover, moving all wikis from our primary data center in Virginia to
the secondary data center in Texas. This is an important periodic test of
our tools and procedures, to ensure the wikis will continue to be available
even in the event of major technical issues in our primary home. It also
gives all our SRE and ops teams a chance to do maintenance and upgrades on
systems in Virginia that normally run 24 hours a day.
The switchover process requires a *brief read-only period for all
Foundation-hosted wikis*, which will start at *14:00 UTC on Wednesday March
1st*, and will last for a few minutes while we execute the migration as
efficiently as possible. All our public and private wikis will be
continuously available for reading as usual, but no one will be able to
save edits during the process. Users will see a notification of the
upcoming maintenance, and anyone still editing will be asked to try again
in a few minutes.
CommRel has already begun notifying communities of the read-only window. A
similar event will follow a few weeks later, when we move back to Virginia.
This is currently scheduled for *Wednesday, April 26th*.
If you like, you can follow along on the day in the public
#wikimedia-operations channel on IRC (instructions for joining here
<https://meta.wikimedia.org/wiki/IRC/Instructions>). To report any issues,
you can reach us in #wikimedia-sre on IRC, or file a Phabricator ticket
with the *datacenter-switchover* tag (pre-filled form here
<https://phabricator.wikimedia.org/maniphest/task/edit/form/1/?projects=Datacenter-Switchover&subscribers=Clement_Goubert>);
we'll be monitoring closely for reports of trouble during and after the
switchover. (If you're new to Phab, there's more information at
Phabricator/Help.) The switchover and its preparation are tracked tracked
in Phabricator Task T327920 <https://phabricator.wikimedia.org/T327920>
On behalf of the SRE team, please excuse the disruption, and our thanks to
everyone in a number of departments who've been involved in planning this
work for the past weeks. Feel free to reply directly to me with any
questions.
Thank you,
--
Clément Goubert (they/them)
Senior SRE
Wikimedia Foundation