[Wikimedia Announcements] Wikimedia sites to move to primary data center in Ashburn, Virginia. Disruption expected.

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[Wikimedia Announcements] Wikimedia sites to move to primary data center in Ashburn, Virginia. Disruption expected.

Guillaume Paumier
[Apologies for cross-posting; this concerns all Wikimedia projects]


Posted today on the Wikimedia Tech Blog:
https://blog.wikimedia.org/2013/01/19/wikimedia-sites-move-to-primary-data-center-in-ashburn-virginia/

Wikimedia sites to move to primary data center in Ashburn, Virginia

Next week, the Wikimedia Foundation will transition its main technical
operations to a new data center in Ashburn, Virginia, USA. This is intended
to improve the technical performance and reliability of all Wikimedia
sites, including Wikipedia.

Engineering teams have been preparing for the migration to minimize
inconvenience to our users, but major service disruption is still expected
during the transition. Our sites will be in read-only mode for some time,
and may be intermittently inaccessible. Users are advised to be patient
during those interruptions, and share
information<https://meta.wikimedia.org/wiki/Wikimedia_maintenance_notice>in
case of continued outage or loss of functionality.

The current target windows for the migration are January 22nd, 23rd and
24th, 2013, from 17:00 to 01:00 UTC (see other
timezones<http://www.timeanddate.com/worldclock/fixedtime.html?msg=Wikimedia+data+center+migration&iso=20130122T17&ah=8>on
timeanddate.com).

Wikimedia sites have been hosted in our main data center in Tampa, Florida,
since 2004; before that, the couple of servers powering Wikipedia were in
San Diego, California. Ashburn is the third and newest primary data center
to host Wikimedia sites.

A major reason for choosing Tampa, Florida as the location of the primary
data center in 2004 was its proximity to founder Jimmy Wales’ home, at a
time when he was much more involved in the technical operations of the
site. In 2009, the Wikimedia Foundation’s Technical Operations team started
to look<https://blog.wikimedia.org/2009/04/07/wmf-needs-additional-datacenter-space/>for
other locations with better network connectivity and more clement
weather. Located in the Washington, D.C. metropolitan area, Ashburn offers
faster and more reliable connectivity than Tampa, and usually fewer
hurricanes.

The Operations team started to plan and prepare for the Virginia data
center in Summer 2010. The actual build-out and racking of servers at the
colocation facility started in February 2011, and was followed by a long
period of hardware, system and software configuration. Traffic started to
be served to users from the Ashburn data center in November 2011, in the
form of CSS and JavaScript assets (served from “bits.wikimedia.org“).

We reached a major milestone in February 2012, when caching servers were
set up to handle read-only requests for Wikipedia and Wikimedia content,
which represent most of the traffic to Wikipedia and its sister sites. In
April 2012, the Ashburn data center also started to serve media files (from
“upload.wikimedia.org“).

Cacheable requests represent about 90 percent of our traffic, leaving 10
percent that requires interaction with our web (Apache) and database
(MySQL) servers, which are still being hosted in Tampa. Until now, every
edit made to a Wikipedia page has been handled by the servers in Tampa.
This dependency on our Tampa data center was responsible for the site
outage in August
2012<https://blog.wikimedia.org/2012/08/06/wikimedia-site-outage-6-august-2012/>,
when a fiber cut severed the connection between our two locations.

Starting next week, the new servers in Ashburn will take on that role as
well, and all our sites will be able to function fully without relying on
the servers in Florida. The legacy data center in Tampa will continue to be
maintained, and will serve as a secondary “hot failover” data center:
servers will be in standby mode to take over, should the primary site
experiences an outage. Server configuration and data will be synchronized
between the two locations to ensure a transition as smooth as possible in
case of technical difficulties in Ashburn.

Besides just installing newer hardware, setting up the data center in
Ashburn has also been an opportunity for architecture overhauls, like
incremental improvements of the text storage
system<https://blog.wikimedia.org/2011/11/18/nobody-notices-when-its-not-broken-new-database-servers-deployed/>,
and the move to an entirely new media storage
system<https://blog.wikimedia.org/2012/02/09/scaling-media-storage-at-wikimedia-with-swift/>to
keep up with the growth of the content generated and curated by our
contributors.

Wikimedia’s technical infrastructure aims to be as open and collaborative
as the sites it powers. Most of the configuration of our
servers<https://blog.wikimedia.org/2011/09/19/ever-wondered-how-the-wikimedia-servers-are-configured/>is
publicly accessible, and the Wikimedia
Labs <https://blog.wikimedia.org/2012/04/16/introduction-to-wikimedia-labs/>initiative
allows contributors to test and submit improvements to the
sites’ configuration files.

The Wikimedia Foundation currently operates a total of about 885 servers,
and serves about 20 billion page views a month, on a non-profit budget that
relies almost entirely on donations from readers.
--
Guillaume Paumier
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