PHP7.2 Migration Guide

PHP 5.6 no longer supported

WordPress is written in PHP and version 5.6 recently reached end of life. This means that security updates are no longer being issued and therefore potential vulnerabilities could be found which will remain unpatched going forward.

We will soon be retiring servers with unsupported PHP versions.

Upgrading your website to PHP 7.2 is therefore a priority.

Migrating your site to PHP 7.2

You will need to carry out the following steps:

1. Reduce the TTL on your live domain names down to 1 hour - do this a few days before completing step 10 to allow time for the TTL propagation to take effect.
2. Reset all file permissions. This can be done using the Pendeo Plugin within WP-Admin, or using our Control Panel > Tools section.
3. Update WordPress Core to version 5.1 (WP version 5.2+ requires PHP7.2). *
4. Review the PHP Errors log for your website and fix any errors.
5. Download, install and run the plugin "PHP Compatibility Checker". Run a compatibility check for PHP7.2.
6. Update your wp-config.php to define('DB_HOST', 'mysql-cluster1');
7. Review any issues found by the compatibility checker. Confirm that these issues are resolved by updated versions of your plugins and theme. TIP review the suppliers' change logs. For any plugins / theme for which the compatibility checker finds errors, you have two options:
   1. If the item has an upgrade which makes it compatible with php7.2 - temporarily deactivate the plugin whilst you complete the upgrade.
   2. If the item is not fixed or compatible with 7.2 you'll need to find an alternative solution. In any case, you must deactivate the item permanently.
8. View your site temporarily on PHP7.2 - see below for instructions. Click through each page and check that everything works as expected. NB if you have deactivate plugins in step 7, some functionality will not work as expected.
9. When you are sure everything is working OK, remove your local hosts entry (created in step 8)
10. Update DNS to point to the new PHP7.2 host.
11. Wait for the DNS to propagate - test that your local environment has the updated record before proceeding.
12. Take a backup and also download the wp-content/plugins and wp-content/theme directory via sFTP.
13. Update WordPress Core to the latest version *
14. Review the PHP Errors log for your website and fix any errors.
15. Browse the site and check that it works.
16. Repeat steps 13 to 15 for all plugins and then for your theme.
17. Re-activate any temporarily deactivated plugins from step 7 - repeat steps 14 to 15.
18. Migration complete.
19. [optional] Change your TTL back to its previous setting.

* It's possible that updating your theme, plugins and/or WordPress core version will cause your site to break. Follow the instructions below about 'Resolving Errors'