User blog:Brandon Rhea/Fandom is upgrading to MediaWiki 1.37 as part of our commitment to keeping the platform up to date

Last month, we announced a number of initiatives that we’re working on here at Fandom to kick off 2022. One of those announcements was that we will be upgrading the platform MediaWiki 1.33 to MediaWiki 1.37, and today I’m excited to walk you through some of the details. The big headline is that the upgrade is going to begin in March! And also, that not much will change. This should be a fairly easy update, especially when you compare how massive of an upgrade the transition to the Unified Community Platform (UCP) was.

In this I’ll get into the details of why it’s so different from UCP, what the rollout timeline is, and what you can expect to see in terms of some minor changes here and there.

What is a MediaWiki upgrade?
Let’s start with the basics. A MediaWiki upgrade means updating to the most recent version of MediaWiki that’s available via the Wikimedia Foundation, which maintains the software that powers Fandom. Think of it like an iPhone or Android update. Every once in a while, your phone asks you to download and install software updates that bring (hopefully) improvements to your phone, security updates, and more. The same is true of MediaWiki. This is our version of a software update.

I mentioned how this would be different from the transition to UCP, so let me explain why for a second using that phone metaphor. Prior to UCP, the Fandom platform was using a heavily modified instance of MediaWiki 1.19, a version of the software which the Wikimedia Foundation had not supported since 2015. Because ours was so modified, it meant we couldn’t keep up to date with the Foundation by upgrading MediaWiki as new versions were released. To do so would’ve broken the site. Some of you might remember the last time we updated MediaWiki pre-UCP, in 2012. It was a massive undertaking that took months to be able to roll out, and the rollout came with a lot of bugs because of all those modifications we made and the custom platform elements that had to be supported along with the update.

Because we were so out of date, the transition to UCP wasn’t like a regular phone update. Normally if you keep up to date with your phone updates, the changes are very minor. Because it’s minor changes here and there. But the transition from UCP was like going from an iPhone 4 to an iPhone 13. It’s a massive set of changes all at once, and it can be pretty overwhelming to have to learn how it works.

This is not that. The benefit of being on UCP now is that we will be able to regularly update MediaWiki, with our intention being to do so about once per year, and avoid massive changes in one big update. So you can rest easy knowing that this will be pretty straightforward this time around!

What are the benefits of upgrading?
Aside from what I already mentioned, there’s plenty of benefits. But hey, you don’t just have to take my word for it. Fandom community members asked for MediaWiki upgrades for years, leading us to the UCP project, and Gamepedia wikis were regularly updated pre-merger. So why not hear from some community members too?

Technobliterator is a long-time admin for the Final Fantasy and Ratchet & Clank wikis. He’s about as hardcore a wiki editor as I’ve ever seen. And what he told me was that “Keeping up-to-date with new MediaWiki software has been extremely beneficial to us. The last update brought great quality-of-life improvements, such as the ability to rename categories or the edit links on WhatLinksHere, that greatly improved the lives of those working on site maintenance. Happy to see the platform continue to stay with the times!”

ProfessorTofty is a long-time editor on the Harry Potter Wiki and Wookieepedia, and a Wiki Specialist on the Community Activations team, so he’s got years worth of experience in how to create content on Fandom and what tools are needed to do so. Tofty told me that “As the foundation upon which Fandom editing is built, it's important to keep MediaWiki up to date so that the platform stays fresh and relevant. For years, Fandom ran on an outdated version of MediaWiki, forcing patchwork solutions to problems and hindering growth. By staying with the latest updates, it helps to streamline the process, ensuring both that problems and bugs can be responded to more quickly and that new features can be easily implemented.”

Like Tofty, Fearless Diva is also a Wiki Specialist and a long-time admin, primarily on the Pretty Little Liars Wiki. What they told me was that, “I have been an editor at Fandom since 2011, and over the years I have seen things that have worked on the platform, and others that haven't or that they needed to be retooled. This upcoming MediaWiki Upgrade is much needed, and will in turn help Fandom editors as a whole get more practice in using the newer/or updated tools. While I understand change can be hard for some, it's better, in the long run, to stay up to date with the upgrades.”

You can also look back on a previous blog from 2020 about the importance of upgrading MediaWiki.

How will the upgrade happen?
We’re planning on rolling out the upgrade in a series of stages, with the goal of having the top 5,000 wikis (which is the vast majority of site traffic) upgraded by the beginning of April. Our engineers have been working behind the scenes since the end of 2021 on a test upgrade, to make sure that everything could go as smoothly as possible and that they could use a test version to inform the plan for how to roll out this update to the community.

The stages are as follows:


 * Stage 1: Community Testing. In this stage, the goal is to have a selection of test wikis and wiki clones rigorously tested and working well on MediaWiki 1.37. We'll have a code freeze, that way we're not adding changes to 1.33 that we'd have to then rebuild in 1.37. Wiki Representatives and staff members will thoroughly test the test wikis and wiki clones in order to find any bugs or other areas we need to improve. And in doing so, we'll identify the list of changes to CSS and HTML that will affect wiki customizations and then share that with the community, especially Dev Wiki where script updates might need to happen. We'll also have a list of wikis we plan to release the upgrade to first.
 * Stage 2: First Rollout. By the end of March, we’ll have migrated the first test communities to 1.37 to make sure the process is running well. Throughout this process, wikis will be manually migrated and then tested afterward, and we have the ability to rollback any migration fairly easily in the event that something isn’t working well. We’ll migrate a variety of wikis, beginning with small ones and increasing the size and complexity of the wikis as we go. At some point in this process, we will also switch the Create New Wiki flow to 1.37.
 * Stage 3: Top 5k Wikis Migrated. By the end of April, the goal is to have the top 5,000 wikis on 1.37. This larger update batch will begin at the end of March. By then, we’ll have spent time testing on the first set of wikis that migrate over and won’t start this larger migration until we’re confident in the results of Stage 2.
 * Stage 4: Long Tail Migrations. Throughout the spring, we’ll automatically migrate the remainder of wiki traffic to 1.37. Our goal is that by the beginning of May, MediaWiki 1.33 is no longer serving any traffic on Fandom.

Of course, exact dates for these might change as we continue in the testing and development process, which is pretty normal for any rollout like this. Prior to the migration of wikis from 1.33 to 1.37, a banner will appear across the site informing the community of the upcoming change along with a link to a help page explaining what changes to expect.

Upcoming code freeze
In order to focus on the new instance of MediaWiki and maintain efficient internal development processes, we will be instituting a code freeze beginning February 28th and wikis will remain in the code freeze until they are migrated onto the 1.37 version of the platform. This means that new code generally won’t be introduced onto the platform during that period of time. However, we will of course be available to fix any critical bugs or make any essential changes to the code that we need to during that time.

What’s changing in the upgrade?
We wanted to keep this staff blog high level, so a detailed list is what that help page I just mentioned is for! If you click on this link, you can find an overview of the changes that have come in each version of MediaWiki since 1.33 so you can know what to expect. Like I said before, we’ll also be working on a detailed list of CSS, HTML, and other potential changes that could impact community customizations so Wiki Representatives and admins can work on that ahead of time.

One thing I wanted to call out explicitly as not changing is the site’s design. While there may be minor visual tweaks here and there due to extension updates between the different versions of MediaWiki, the site’s skins&mdash;FandomDesktop and FandomMobile, part of last year’s Unified Consumer Experience (UCX) project&mdash;are NOT changing.

If you have any questions about the rollout or upcoming changes, feel free to reach out to your Wiki Representative, to Special:Contact, or post them here and we’d be happy to answer them in the comments!