Having long cache lifetimes and expire times has major advantages, which means that it’s important to use Varnish® with Drupal for performance improvements. However, when changes are made or new content is published, you don’t want to wait a long time for visitors (including non-authenticated users) to see the changes. In these cases, you should periodically purge your Varnish cache.
Select from the following methods to purge your Varnish cache:
The Acquia Purge module is the fastest and most convenient way to purge Varnish cache on Cloud Platform. Acquia Purge works within your Drupal application to clear Varnish cache on Cloud Platform and works with other modules to update caches and external caching layers.
For more information about installing and using Acquia Purge for Drupal 7, see Acquia Purge page on Drupal.org.
The Purge module clears URLs from reverse proxy caches like Varnish and also
http PURGE request to them. It works with the Cache Expiration
module to act on events that are likely to expire URLs from the proxy cache
and interact with Rules and Drush. This results in delivering faster content
updates to end users. Acquia Purge is recommended on Cloud Platform
because it has many of the same features, and the maintainers for Purge and
Acquia Purge work closely to ensure compatibility.
If you absolutely must purge a page manually from Cloud Platform, you can learn how to manually purge a page.
Cloud Hooks allow you to automate almost anything as part of your workflow actions. A Cloud Hook is a script in your code repository that Cloud Platform executes on your behalf when a triggering action occurs (for example, when a database, some code or some files are copied from one environment to the other). You can implement Cloud API Varnish cache clears as part of Cloud Hooks triggers. For example, when you are deploying code from the Development to the Staging.
Acquia strongly recommends that you use extreme caution when purging the Varnish cache on a production domain.
Although Acquia Purge is the preferred and safest method of cache purging, there are some other methods that you can use if necessary: