All,

We will be proceeding with the datacenter switchover plan this coming Tuesday (Jan 22, 2013), unless we discover some unexpected and insurmountable issues in our tests between now and then.

During the 8-hour migration window on the 22nd, 23rd and 24th (from 17:00 UTC to 01:00 UTC hours / 9am to 5pm PST), there would be times (lasting about 30 minutes) where the site would be set to "read-only" mode, to facilitate master database switchovers from one datacenter to another. While the site should be available to readers, no new contents could be created, edited or uploaded.

We are aware of the inconvenience and we have put together plans to minimize such annoyances, e.g., automating much of the procedures, mitigating known risks, and performing tests to identify issues prior to deployment. Given the scale and complexity of this migration, we do realize not all operational impact is predictable. Some users could experience intermittent site unavailability and/or performance issues unfortunately.

You can follow the migration on chat.freenode.net http://irc.freenode.net (and not irc.freenode.org as mentioned in previous email) in the #wikimedia-operations channel.

Thanks, CT Woo

---------- Forwarded message ---------- From: Ct Woo ctwoo@wikimedia.org Date: Fri, Jan 11, 2013 at 12:07 PM Subject: Update on Ashburn data center switchover / migration – target date is week of 1/22/13 To: Wikimedia developers wikitech-l@lists.wikimedia.org, Development and Operations Engineers engineering@lists.wikimedia.org

All,

The Migration team is in the last lap on completing the remaining tasks to ready our software stack and Ashburn infrastructure for the big switchover day.

Per my last update,http://lists.wikimedia.org/pipermail/wikitech-l/2012-October/063668.html with the Fundraising activity behind us now, the team has scheduled the *week of 22nd January*, 2013 to perform the switchover. We are going to block a 8-hour migration window on the *22nd, 23rd and 24**th*. During those periods, *17:00 UTC to 01:00 UTC hours (9am to 5pm PST*), there will be intermittent blackouts and they will be treated as 'planned' outages. You can follow the migration on irc.freenode.org in the #wikimedia-operations channel.

The team is putting the finishing touches to the last few tasks and we will make the final Go/No decision on 18th Jan, 2013. An update will send out then. For those interested in tracking the progress, the meeting notes are captured on this wikitech pagehttp://wikitech.wikimedia.org/view/Eqiad_Migration_Planning#Improving_Switchover .

*Please note that we will be restricting code deployment during that week, allowing only emergency and critical ones only.*

Thanks.

CT Woo