LCache

This module provides a combination L1/L2 cache using a combination of APCu as L1 with a database as L2 (and for coherency management among the L1 caches).

Currently only supported on Pantheon, but there's nothing that inherently relies on anything Pantheon-specific.

Upstream library: https://github.com/lcache/lcache

Usage

1. Upload the module to your site. a. If using Composer to manage your site's modules:

   composer require drupal/lcache
   

   b. If not using Composer:

   drush dl lcache
   cd sites/all/modules/lcache
   composer install --no-dev
   

   c. If you are pushing to a remote location (e.g. Pantheon) you will need to force-commit the 'vendor' directory so that the core lcache library is pushed along with the module:

   git add --force vendor
   git push origin master
   

2. Install the module (so Drupal creates the database schema).

3. Configure settings.php to use the cache:

   $conf['cache_backends'][] = 'sites/all/modules/lcache/lcache.cache.inc';
   $conf['cache_default_class'] = 'LCache';
   // The 'cache_form' bin must be assigned to non-volatile storage.
   // And if you use page cache, you probably don't want it in LCache.
   $conf['cache_class_cache_form'] = 'DrupalDatabaseCache';
   $conf['cache_class_cache_page'] = 'DrupalDatabaseCache';
   

With Composer Manager

Composer Manager is not officially supported for use with LCache, but there are reports of it working properly by adding the following early (before LCache is included) in settings.php:

require_once DRUPAL_ROOT . '/sites/all/modules/composer_manager/composer_manager.module';
composer_manager_register_autoloader();