The following collection of patches are useful performance and scalability tweaks that can be applied to Drupal websites. This collection will continue to grow, and is being maintained as a reference page for our online performance and scalability book. As new versions of Drupal are released, updated version of these patches will be added to this page.

To learn more about how these patches work, where they came from, and if they've been merged upstream, you can click the readme link following each patch's brief description. We welcome all feedback, and suggestions for other patches that should be included in this collection.

• CDN
  Patch Drupal core to serve static content from a CDN. This patch will serve user-uploaded files (if using public downloads), CSS files, JavaScripts, and theme images from a CDN. [readme]
  [6.0] [6.1] [6.2] [6.3] [6.4]

• drupal_lookup_path
  Optimize a database query in drupal_lookup_path to not count all rows in the url_alias table on each page load. Useful for websites with a large url_alias table and a transactional database, on which the original query is showing up in the slow query log. [readme]
  [6.0] [6.1] [6.2] [6.3] [6.4]

• drupal_to_js
  If using PHP 5.2 or later (as required by Drupal 7+), drupal_to_js() can be simplified by using PHP's built-in json_encode() function. [readme]
  [6.0] [6.1] [6.2] [6.3] [6.4]

• external pagecache
  Serve anonymous pages directly from a cache without accessing the database. Requires that sessions and the page cache be managed externally, such as by memcache, and that aggressive caching is enabled. [readme]
  [5.7] [5.8] [5.9] [5.10]