PHP 8.1 Migration

The following is a copy of

PHP Migration

As originally presented at the Drupal Community Meeting (7th April 2022), PHP 7.x is reaching end-of-life November 28 2022. This is the default approach by the PHP Group, actively supporting each release branch for two years following its initial stable release. During these two years, bugs and security issues are fixed and released accordingly. Once the two year period of active support is finished, each branch is then supported for an additional year for critical security issues only.

Currently, CERN uses PHP version 7.4, whose support ends November 28 2022.

In preparation of Drupal 10, CERN is moving directly to PHP 8.1.

Who does this impact?

In short:

  1. If your website relies on the CERN Drupal Distribution, no action is necessary.

  2. If your website utilises custom modules, you must take action.

If you are unsure as to whether or not your website uses custom modules, please confirm that:

  • You, or anyone on your team, has not created and configured a dedicated composer project; and
  • the custom modules list has an empty modules.

If you do have custom modules installed, you must ensure that the version you have installed is compatible with Drupal >= 9.4.0 and PHP 8.1. This can be verified by viewing the dedicated release page of each individual module. If, for instance, you are using a local installation of better_exposed_filters (see, version 8.x-5.2 works with Drupal ^8.8 || ^9, whereas version 6.0.1 works with Drupal ^9 || ^10. In this instance, you must ensure that you are using version 6.0.1. In general, it always a good idea to use the newest available release of a module that is not an alpha or beta release. Please refer to this guide in order to update your modules.

I am impacted, what now?

It is first and foremost important to accentuate how custom modules are your responsibility. This means anything not in the CERN Drupal Distribution, i.e. custom (self-authored or modified) and community contributed modules. In all cases, you must

  1. Ensure compatibility with PHP 8.1;
  2. ensure compatibility with Drupal 9.4 / 10.x;

as well as

  1. ensure continued maintenance.

We recommend the following resources to ensure compatibility:

If you have any questions, please refer to the Drupal Community Forum.

Migration Process

The following steps outline the migration process to PHP 8.1.

  1. A clone of your website, e.g., will automatically be created in a PHP 8.1 environment as

Once the clone is up and running, you will receive a notification (e-mail via the Notifications Service) with a direct link to your newly created clone. The steps outlined on this page will be included in the e-mail, too.

  1. You must then validate that your website looks and functions as expected.

This means browsing through some of your pages and verifying that it behaves as it should. If you are utilising different content types, and perhaps have customised pages, we recommend checking at least one of each type. Please remember to check both as an authenticated and anonymous user to ensure permissions remain unchanged.

The next step depends on whether you use custom modules or not.

Sites without custom modules

  1. If your website does not utilise any custom modules, it is expected to function correctly. However, kindly note that a small selection of modules previously included in the CERN Drupal Distribution has been discontinued due to no compatible releases being available. If you relied on any of these modules, you website should still work, but some functionality will no longer be available. If something unexpected does not work, or it someone looks or behaves weirdly, please submit a SNOW ticket.

If everything looks correct, no further action is needed.

On 14 November, your production website will be upgraded automatically.

The preview site will automatically be deleted.

Sites with custom modules

  1. If your website utilises custom modules, you must ensure compatibility.

Website preview is compatible

If your preview website is already compatible, no other action is necessary. This scenario likely means you are already actively upgrading your custom modules: We appreciate you doing this, and encourage you to continue this practice to ensure your website remains secure and compatible moving forward. By 14 November, your production website will be upgraded, and approximately two weeks later, the clone will automatically be deleted.

Website preview is not compatible

If your preview website is not fully compatible, or lacks some functionality, you most likely need to update one or more custom modules. You must then work on the clone to ensure compatibility as your production website does not yet run in a PHP 8.1 environment. Kindly refer to this guide to learn how to update modules. If you face any problems doing this, please post on the Drupal Community Forum, or submit a ticket.

You will have two weeks, until 14 November to fix your website, before the automated upgrade to PHP 8.1 happens. If this time is not sufficient you can request for an extension until 28 November.

This action must be done before 14 November.

:warning: New content added to your production website is not automatically mapped to the clone website after its creation!

Upgrading modified website previews to production

  1. If you did not add new content to the primary during the migration period, but you made changes to the clone/preview to ensure compatibility with PHP 8.1, We recommend the following approach: Before the deadline to upgrade ends (either the default two weeks, or 28 November, if you requested an extension), go to the Webservices Portal and promote the clone to primary by clicking the Set as primary env toggle. We consider the migration period to begin on 24 October until the deadline of the upgrade.

  2. You added new content to the primary, and also made changes to the preview instance.

In this instance, there is no automated flow.

We recommend you either:

2.a) copy the new content to the preview instance before upgrading as mentioned above in Upgrading custom previews to production, point 1., or
2.b) create a new clone via Add environment, choose release v9.4-2 and copy the changes you performed to your clone/preview to the new environment instance just created.

Once that is done promote it to primary as mentioned above in Upgrading custom previews to production, point 1.. When the deadline is reached, if your production site is already running the v9.4-2, you do not need to perform any other action. Approximately two weeks after, we will cleanup all migration related resources, and upgrade all other environments as well.

Hello, when trying to access the link provided for my website:](
I get this message:
The website encountered an unexpected error. Please try again later.
Should I simply wait and try again? Or is there something else?


All our sites break with an error thrown by “CERN components” module, opened tickets.

Hi Roberto

Thanks for flagging. We are investigating.


Hi Marton

Thanks for flagging. We are investigating.


Thank you. Would it be possible to postpone this upgrade?

You are notifying users 5 working days in advance of a breaking change.

Hi Marton

It is possible to request an extension if necessary. However, kindly note that we first gave a heads-up regarding the need to ensure PHP 8.1 compatibility back in our Drupal Community Meeting in April, and again in our Community Meeting last month. That said, if errors are caused by CERN-official modules, these are naturally not on you. Could you please provide a couple of websites on which you are seeing this error?

Thank you!

There is no actionable item on “giving heads up” in a presentation that you will upgrade to a new version of Php several months later. Also, as we have expressed quite expicitly in the community meeting, you cannot expect hundreds of website owners Cern-wide to attend community meetings just to make sure their website will stay online.

The concrete notification, with the preview was sent out minutes ago, even though you write “You will have two weeks…to fix your website”.

Answering your question, the broken websites are:

Hi Marton

Thanks for forwarding the two websites; we are investigating. I am happy to hear that the financeclub seems to be functioning correctly! I appreciate where you are coming from in regards to giving a heads-up, but as outlined repeatedly throughout our documentation, past community meetings and e-mails, the need to ensure your website is compatible applies especially to those who chooses to customise their website beyond the functionality offered via the CERN Drupal Distribution.

Any website is a living and breathing piece of software; both from a security perspective and a usability perspective. Choosing to install community-contributed modules means assuming responsibility for ensuring continued compatibility. Sticking with the CERN Drupal Distribution allows you a hands-off, carefree approach insofar that the Web Team assumes responsibility of the included modules. In this instance, it seems as though you and Roberto are both impacted by the same error from our CERN Components module. We apologise for the inconvenience and are actively working on applying a patch. No action will be necessary on your part to receive this, and we expect to have it up shortly.

Thank you!

Hi @rperruzz and @maarton!

We have bumped CERN Components to version 3.0.5 to address the issue you have reported. The patch is being rolled out automatically and will be applied to your website(s) within the next 30 minutes. Please refresh caches accordingly. Thanks for reporting, and apologies for the inconvenience.



Thank you for the upgrade. It did not fix the issue but I’ll update the SNOW ticket to take the discussion offline.

Hi Marton

I can access just fine; which error are you seeing?


Thank you for the follow up, please see the SNOW ticket with screenshots and details. (Any content, for example this throws error)

Hi Marton

This is a separate issue, but one we have identified and rectified now. Updates are currently being rolled out and will be applied, like the prior one, automatically without any action necessary from your end. If you continue to experience issues on your website, please ping me directly on Mattermost as we may need to boot up a local copy for faster testing. The handful of websites we tested locally before pushing out did not exhibit this behaviour.


Hi, we have also encountered the an unexpected error message caused by CERN components module:
Is this something similar to the issue above?

Hi Jiahui

That is a different issue, but an issue nonetheless. Thank you for flagging. We have already applied a patch for this and are preparing to roll this out as well. I am including ams02 with Marton’s molflow for our local testing as both websites exhibited behaviour we did not catch during our internal tests.

Thank you!

Hi @maarton and @jiwei

We have pushed another update that addresses both the issues you have reported.