The purge module clears URLs from reverse proxy caches like Varnish, Squid or Nginx by issuing an http PURGE request to them. It works in conjunction 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 allows delivering content updates faster to end users.

Requirements

• One or more reverse proxy caches like Varnish (recommended), Squid or Nginx that point to your webserver(s).
• Varnish needs a modification to its configuration file. See this section in the Varnish chapter of the Drupal handbook
• Squid needs to have purging enabled in its configuration.
• Nginx needs an extra module and configuration. See the installation hints below and the included the README.txt
  
  Also see this issue #1048000: nginx support
  for more background info and compiling/installation hints
• A cachable version for Drupal 6. This can be an official Drupal 6 release with a patch applied or use Pressflow, a cachable friendly fork of Drupal. Drupal 7 works out of the box.
• PHP with curl enabled. The Purge module uses curl for issuing the http PURGE requests.
• Purge requires the expire module

Installation

• Unpack, place and enable just like any other module.
• Navigate to Administration -> Site configuration -> Purge settings
• Set your proxy URL(s) like http://localhost or http://192.168.1.23:8080 http://192.168.2.34:8080
• If your using nginx you need to specify the purge path and the get method in
  
  your proxy setting like this:
  http://192.168.1.76:8080/purge?purge_method=get
• If your using the Acquia Dev Cloud or the Acquia Managed Hosting servcies you'll need to configure like: http://yousite.com/?purge_method=ah I recommend you use the platform specific module Acquia Purge instead to overcome limitations in Acquia Purge 1.x. These will be addresses in a sustainable way in the upcoming 2.x branch of Purge.
• Optional: Install Rules for advanced cache clearing scenarios or Drush for command line purging. Both are supported through the expire module.

Roadmap

The 1.x versions of Drupal 6 and Drupal 7 will not longer receive new features, just bugfixes and are believed to be stable.

The 7.x-2.x branch will be the place where new features will be developed. The Drupal 6 branch may receive backports of some new features but most likely not all of them, depending on demand and community involvement. Some of the new 2.x features we're thinking about:

• New configuration interface
• Proxy settings auto discovery
• Dropping hard dependency on Expire and Curl library
• More request handlers besides concurrent curl requests.
• Wildcard purge url's including purging of whole domains.
• Your feature here

See #1826926: Purge 2.x roadmap and progress
for more details and status updates.