As reported two weeks ago, we’re planning to deploy MediaWiki 1.18 to all wikis, starting today (Tuesday, October 4, 23:00-03:00 UTC). We have been running MediaWiki 1.18 on several wikis already, representing about 2% of our total traffic. A big thank you to the early adopter wikis; it was very helpful getting some real world testing prior to deploying to the other 98%.

Our deployment process works like this. During our four hour deployment window, we’ll be deploying to several wikis sequentially. Our tentative plan for today is deploying first to, then, then, and then probably a few more sequentially before deploying to the rest in bulk.  At the end of our window, we will be stopping deployment, even if we’re not done (scheduling a followup window if needed).

To report issues in real time (especially during the deployment window), IRC is the best venue; please join us in #wikimedia-tech on Freenode (web access). For those of you that are comfortable with Bugzilla and other development tools, we would love your help with confirming issues and getting appropriate issues filed in our bug tracker. If you don’t feel comfortable using Bugzilla, you can leave a message on the talk page of our announcement on meta. Our developers can keep track of issues much better when you use Bugzilla, so filing it there makes it more likely your problem will be noticed and eventually addressed.

Thanks for your patience!

Rob Lanphier
Director of Platform Engineering

Update: October 5 05:14 UTC – we didn’t get as far as we wanted, but we deployed to,,, and  We’re planning to have one more deployment window in a little less than 18 hours (October 5, 23:00-October 6, 03:00 UTC) to deploy to the remaining wikis.