Information for: DEVELOPERS   PARTNERS

Updating Lightning

Lightning has a two-pronged update process. When initially installed, Lightning includes a useful, near-complete default configuration for your website, but after installation, all of that configuration is owned by your website. Since your website owns the configuration from that point on, Lightning cannot safely modify your website without potentially changing its behavior, or, in a worst-case scenario, causing data loss.

As it evolves, the Lightning default configuration can change, and in certain limited cases, Lightning will attempt to safely update configuration that it depends on. This configuration will usually be locked to prevent you from modifying it. Otherwise, Lightning will not modify your configuration, respecting the fact that your website owns it.

This set of behaviors, then, requires that you use the following process to update your Lightning installation.


Critical security updates, in general, can be accomplished without waiting for the Lightning distribution update. However, Acquia will attempt to update the distribution as quickly as possible after any security updates.

Before you begin

Depending on the modules or libraries included with an Lightning release, specific versions of Lightning may require additional configuration or upgrade steps. Before starting a version upgrade, to determine if your version requires these needed steps, see the Configuration updates section of the Lightning update instructions on GitHub.

You must follow any additional update instructions specific to your version of Lightning when upgrading your files and database.


After you ensure that you have addressed any additional requirements, if you previously used our Composer-based project template to install Lightning, complete the following steps to update your codebase’s installed version of Lightning:

  1. From a command prompt window, navigate to your your project: cd [/path/to/YOUR_PROJECT]

  2. Execute composer update to download updates to modules and libraries

  3. Perform any needed database updates by using one of the following methods:

    • Drupal user interface - Visit (where is the URL for your website) and follow the on-screen instructions.

    • Drush - Update your database manually from a command prompt window by using the following steps:

      1. Perform any needed database updates by executing the following command:

        drush updatedb --yes
      2. Clear and rebuild caches by executing the following command:

        drush cache-rebuild
  4. Perform any needed configuration Lightning updates by using the instructions from one of the following resources:

    • The manual update instructions listed in the Lightning release notes
    • The file included with Lightning