MediaWiki 1.17/Wikimedia deployment

MediaWiki is the software that runs Wikipedia and all the Wikimedia wikis.

An upgrade to a newer version of MediaWiki (1.17) is scheduled during two deployment windows in the next week
 * (Done) First wave – This wave was Friday, February 11, 6:00 UTC – 12:00 UTC (10pm PST Thursday, February 10 in San Francisco). This first wave was on limited set of wikis.  See Wikimedia Techblog post about the deployment for more information.
 * Second wave – Wednesday February 16 (between 6:00 UTC – 12:00 UTC) – most wikis. We'll be deploying more debug code and deploy to as many wikis as we can without overloading the site.

The most visible change for Wikimedia users will be the deployment of ResourceLoader. The upgrade took place at 13:00, but was rollbacked again due to issues with the servers.

ResourceLoader optimizes the use of JavaScript in MediaWiki, speeding up delivery of JavaScript by compressing it sometimes, and cutting down on the amount of unused JavaScript that gets delivered to the browser in the first place.

The installation of ResourceLoader may cause compatibility issues with existing JavaScript code. If you maintain JavaScript code on your home wiki, please see the documentation linked at ResourceLoader to make sure it continues to work with ResourceLoader.

The tech team have been doing their best to make the upgrade go smoothly, but some issues may arise. Please help us solve them by reporting them (see below).

Thank you for your support and your understanding.

What to do if you encounter an issue

 * Wait a few minutes; the tech team may be already aware of the issue and working on it.
 * Join the #wikimedia-tech channel on Freenode.
 * If you have an IRC client, use this direct link: #wikimedia-tech
 * Otherwise, see IRC or use Freenode's webchat platform.
 * If you encounter an issue after the upgrade, please report it on our bug tracker.

More information

 * New two-part schedule for 1.17 deployment - Announcement of the second deployment attempt on the Wikimedia Tech blog
 * Draft release notes for MediaWiki 1.17.