.. include:: ../../common/global.rst

Memcache
========

The following documentation describes how to configure the `Memcache API and
Integration <https://www.drupal.org/project/memcache>`__ (Memcache)
module for Drupal 8. The Memcache module provides an API for using
Memcached and the PECL Memcache or Memcached libraries with Drupal and
provides backends for Drupal's caching and locking systems. The most
complete and up to date documentation is included with the module, in
the `README.txt
<http://cgit.drupalcode.org/memcache/tree/README.txt?h=8.x-2.x>`__
file.


.. _blt-memcache-ac-acsf:

Acquia Cloud and Acquia Cloud Site Factory
------------------------------------------

To enable memcache integration in a Cloud hosting environment, ensure the
`acquia/memcache-settings Composer package
<https://github.com/acquia/memcache-settings>`__ is installed. If this package
is present, Acquia BLT will include the relevant settings files to enable
memcache integration. No additional setup or configuration is required.

.. _blt-memcache-local-dev:

Local Development
-----------------

The below has been tested with DrupalVM as configured through
Acquia BLT's ``blt vm`` command, but should also work for most
CI environments where the memcache back end is ``localhost`` on port ``11211``.

Add the below statements to an environment's ``local.settings.php`` to
use memcache as the default back end for Drupal's caching and locking
systems. The memcache module does not need to be enabled with the
snippet below, but may need to be if this configuration is removed. Note
that the below configuration explicitly overrides the default bins for
the discovery, bootstrap, and configuration cache bins because Drupal core
permanently caches these static bins by default.

.. code-block:: text

   // Include a unique prefix for each local Drupal installation.
   if ($is_local_env) {
     $settings['memcache']['key_prefix'] = $site_dir;
   }

   require DRUPAL_ROOT . "/../vendor/acquia/blt/settings/memcache.settings.php";

.. Next review date 20200423