To enable Memcached on your website hosted by Cloud Platform, you must install the Memcache API and Integration module in your codebase, and configure the module for use.
When configuring your website to use Memcached, be aware of the following considerations:
- Do not edit the
memcache_key_prefix
ormemcache_servers
settings, as Cloud Platform adds the correct values in Acquia-specific code defined by the Acquia require line, or otherwise available by default on Cloud Next. Altering these values can cause unexpected behavior. - If your website uses either automated testing or the
memcache_admin
submodule, you must enable the Memcache API and Integration module. Although the current Drupal version does not require you to enable the module, Acquia recommends you to enable the module to receive notifications about module updates. - For more information about stampede protection and database locking, see Enabling stampede protection and moving locks into memory.
Configuration for the current Drupal version
For Memcached to function, you must provide additional configuration code that enables autoloading, and identifies Memcached as an alternative cache back-end.
To configure your website for Memcached, make the following changes to your codebase, depending on your subscription type:
Configuration for Drupal 7
If you are installing the module on a Drupal 7 website, you must enable the module before modifying settings.php
, or you will receive a ServiceNotFoundException:
error message.
To configure your Drupal 7 website for Memcached, make the following changes to your codebase, depending on your subscription type:
Allocating memory to Memcached
Using binary protocol
Disabling auto-enablement of Memcached on Cloud Next
To disable Memcache integration with Drupal on Cloud Next, you can follow either of the following options:
Set the Memcache memory limit value to 0 through the Cloud Platform user interface or the Acquia Cloud API. This disables the Memcache service for every Drupal instance running within that environment.
Access the Drupal site’s
settings.php
file and add thedefine('AH_NO_MEMCACHE_INCLUDE', 1);
statement. This only controls the automatic injection of the Memcache integration code, and is independent from turning the Memcache service on or off. If you use this method, you must do the following. If you do not do these steps, the system might use Memcache with non-recommended configurations, thereby causing issues.Disable the Drupal memcache module.
Remove any integration code that adds the Memcache support from your
settings.php
file.