Preserve page cache

The module customizes Drupal's page cache to disable tag based invalidation (of the page cache only).

When reverse proxy or CDNs without tag-based cache invalidation rules are in used, other (time-based, url-based) purging strategies must be applied. In that scenario it's beneficial to keep the internal page cache of Drupal active just as external caches, so that in case of external cache misses (e.g. due to cache size constraints or per-region caches) the page can be served from Drupal's cache again.

The module is achieving this by not setting cache tags when writing cache entries, so caches are not invalidated by different cache tags but only expire after a certain time.

The module comes with one exception: It keeps the node:{ID} cache tag for node pages, so those are invalidated on updates immediately.

Contribute

• Reach out at #drunomics-contribute @ the Drupal Slack!