As the release of Drupal 9 approaches, organizations are starting to think about when to upgrade to Drupal 9. Quick Drupal adoption isn't automatic. Historically, it's taken years for some significant Drupal versions to gain traction. With a relatively short window between the Drupal 9 release and Drupal 8's end-of-life, however, organizations must move more quickly to adopt Drupal 9 or make other arrangements.
No penalty for early Drupal 9 adopters
A common strategy for many technology release cycles is to avoid the initial version of a major software release. Some organizations wait until one or more point releases after a new version, while others prefer to wait months or even years after a major version release for things like bug fixes, additional features, and helpful resources created by early adopters. In the Drupal world, this delay is often exacerbated by waiting for contributed modules to be compatible with the new version.
The nice thing about Drupal 9 is that there is no penalty for early adopters, so there's no reason to wait for a later version. The initial Drupal 9 version release introduces zero new features. Drupal 9.0 core code matches Drupal 8.9 core. The only differences between Drupal 9.0 and Drupal 8.8 or 8.9 are the removal of deprecated code and required upgrades to third-party dependencies.
The primary consideration is whether or not your favorite contributed modules have declared that they are Drupal 9 compatible. With past upgrades, waiting for contributed modules to be ready for the new Drupal version caused months or even years of delays. But the Drupal 9 upgrade path for contributed modules is relatively easy, so they should be able to adapt quickly. Many modules are already compatible, and others will need minimal changes.
When your code is ready
One of the core components of the Drupal 9 upgrade is the removal of deprecated code in Drupal 8. However, this means that when you're planning your release window, you'll need to schedule some time for the pre-work of auditing and refactoring deprecated code. If you've already been doing this, you may not need to pad your schedule to compensate for this work. We'll dive deeper into how to get your code ready in a future article.
In addition to scheduling time to address code deprecations, you'll also need to give yourself time to address any third-party dependencies that require newer versions in Drupal 9. When you're looking at when to upgrade to Drupal 9, you should do it after you've had a chance to resolve any third-party dependency updates that conflict with other things in your stack. If you've got a contrib module or custom code that requires an older version of a third-party dependency, but Drupal 9 calls for a newer version of that dependency, you'll need to make a plan and address this conflict before you upgrade to Drupal 9.
Consider other website work
Many organizations have traditionally used major Drupal version migrations as a time to plan overall website redesign projects, information architecture work, and other web development projects. Because the upgrade to Drupal 9 is more like a minor release than a major one, there's no need to deep dive into information architecture - there's no migration! That means your organization needs to establish a new strategy for these projects; we're working on an upcoming article to cover web development strategy for Drupal 9 for more insights around this.
If business logic dictates that your organization plan other web development projects for this year, make sure you give yourself time to complete the Drupal 9 upgrade before Drupal 8 reaches end-of-life in November 2021.
Take the availability of preferred partners and development teams into account
If you're planning to work with vendor partners, make sure you factor their availability into your project plan. With an upgrade window of slightly over a year between the release of Drupal 9 and the end-of-life of Drupal 8, some vendor partners may have limited availability, especially if yours is a larger project. Planning ahead helps to ensure you can work with your preferred partners; otherwise, you might add the stress of working with a new partner into the mix.
At the same time, don't forget about internal initiatives such as serving multiple stakeholders. For example, doing new feature development for content editors while simultaneously maintaining an up-to-date platform consistent with your organization's security policies can mean a dance to prioritize development resources to meet everyone's priorities and deadlines. While this complicates the release planning process, it's essential to consider these factors when determining the timing of upgrading to Drupal 9.
We dipped our toes into these considerations in Drupal 8 Release Planning in the Enterprise, and hope to release an updated version of this article soon for Drupal 9 release planning.
Missing the Drupal 9 upgrade window
To summarize, you should upgrade to Drupal 9 earlier rather than later. But what if your site can't upgrade to Drupal 9 before Drupal 8 reaches end-of-life? Unlike Drupal 7, Drupal 8 does not have an extended support program. The upgrade from Drupal 8 to Drupal 9 is such a minor replatforming effort compared to prior versions that the decision was made not to offer an extended support program for Drupal 8.
Support will continue through November 2021 for sites upgraded to 8.9.x, but support for that version ends when that Drupal 8 end-of-life date arrives. Older Drupal 8.x versions will cease getting support before that date; 8.7.x stops getting security support as of June 3, 2020, and security support ends for Drupal 8.8.x on December 2, 2020.
Long-term, your organization needs a plan to upgrade to Drupal 9, or to consider other options. A future article in this series offers more information about what that plan might look like.
Thanks to the Lullabot team for contributing to this article and to Dachary Carey for drafting it.