Cloud Platform leverages a stack of technologies specifically tuned to the needs of high-availability enterprise Drupal. Key elements of the stack include:

• (Optional) Cloud Platform CDN for global cached content delivery (Fastly)

• Varnish® and Nginx on a pair of balancers

• Apache, Memcached, and APCu on one or more infrastructure

• Distributed file system

• MySQL on the database layer

• Code deployment using Git

When migrating to Cloud Platform, you must change your application’s code and configuration to leverage these components effectively. For example, to connect to your database on a Cloud Classic environment, you must include a file maintained by Acquia that points to the active database node, regardless of what environment the code is used in. If your primary database node becomes unavailable, this configuration redirects database queries to the secondary database node.

Your application may require additional changes to connect to Memcached or to leverage Varnish for improved performance.

Apart from these basic changes, some applications may require more effort to bring them in line with best practices. For example:

• Files in nonstandard locations (outside of sites/[site]/files)

• Modules that prevent Varnish from caching (for more information, see Modules to use with caution on Cloud Platform and Modules and applications incompatible with Cloud Platform)

• Complex .htaccess files

• Customizations of how Drupal interacts with the database

Any of these items may present challenges during onboarding.

Even if your application has been running without any issue on other hosting platforms, Acquia recommends you to ensure that all aspects of your application are fully compatible with Acquia’s platform. If you’re developing a new application, use Acquia’s tips to ensure that your build follows best practices from the beginning.

Ensuring compatibility with Cloud Platform