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Enabling Memcached on Cloud Platform

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 or memcache_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 Acquia 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 Drupal 9 doesn’t require you to enable the module, Acquia recommends enabling 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.

Important

Be sure to test any of the procedures provided by this documentation page on a non-production environment before implementing them on your production environment.

Configuration for Drupal 9

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:

Note

For environments running on Acquia Cloud Next technologies, steps 2 and 3 aren’t required because Memcache configuration logic is included automatically. To exclude this logic on your environments, add the following line to your settings.php file:

define('AH_NO_MEMCACHE_INCLUDE', 1);

  1. Download the Memcache API and Integration module, and then add the module to your codebase in the modules/contrib/memcache directory.

  2. Download cloud-memcache-d8+.php, and then add it to your codebase in the sites/default directory.

  3. For each website that requires Memcached, edit the Cloud Platform database require line in settings.php with a PHP include() or require() statement, similar to the following example:

    if (file_exists('/var/www/site-php')) {
       require('/var/www/site-php/mysite/mysite-settings.inc');
    
       // Memcached settings for Acquia Hosting
       if (file_exists(DRUPAL_ROOT . '/sites/default/cloud-memcache-d8+.php')) {
          require(DRUPAL_ROOT . '/sites/default/cloud-memcache-d8+.php');
       }
    }
    
  4. Rebuild caches by running the following command, replacing [example.com] with the domain name of your website:

    drush cr --uri=[example.com]
    
  5. Truncate all cache_ tables in the database for the website.

Memcache is now enabled for your website. If you need assistance, contact Acquia support.

  1. Download the Memcache API and Integration module and add the module to your codebase in the modules/contrib/memcache directory.

  2. Download acsfd8+.memcache.settings.php, and then add it to the factory-hooks/post-settings-php directory. For more information about the post-settings-php hook, see Altering values in settings.php with hooks.

  3. Rebuild caches by running the following command, replacing [example.com] with the domain name of your website:

    drush cr --uri=[example.com]
    
  4. Truncate all cache_ tables in the database for the website.

Memcache is now enabled for your website. If you need assistance, contact Acquia support.

For Acquia BLT users

BLT users that continue to experience issues should submit a ticket to the Acquia BLT issue queue.

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.

Note

For Drupal 7 environments running on Acquia Cloud Next technologies, step 2 isn’t required because Memcache configuration logic is included automatically. To exclude this logic on your environments, add the following line to your settings.php file:

define('AH_NO_MEMCACHE_INCLUDE', 1);

To configure your Drupal 7 website for Memcached, make the following changes to your codebase, depending on your subscription type:

  1. Download the Memcache API and Integration module, and then add the module to your codebase in the sites/all/modules/contrib/memcache directory.

  2. Download cloud-memcache-d7.php, and then add the contents of the file to your website’s settings.php file, after the Acquia database require line.

  3. Clear caches by running the following command, replacing [example.com] with the domain name of your website:

    drush cc all --uri=[example.com]
    
  4. Truncate all cache_ tables in the database for the website.

Memcache is now enabled for your website. If you need assistance, contact Acquia support.

  1. Download the Memcache API and Integration module, and then add the module to your codebase in the sites/all/modules/contrib/memcache directory.

  2. Download acsfd7.memcache.settings.php, and then add it to the factory-hooks/post-settings-php directory. For more information about the post-settings-php hook, see Altering values in settings.php with hooks.

  3. Edit the file, modifying the following lines if they do not correspond to the location of the Memcache API and Integration module in your codebase:

    $conf['cache_backends'][] = 'sites/all/modules/contrib/memcache/memcache.inc';
    
    $conf['lock_inc'] = 'sites/all/modules/contrib/memcache/memcache-lock.inc';
    
  4. Clear caches by running the following command , replacing [example.com] with the domain name of your website:

    drush cc all --uri=[example.com]
    
  5. Truncate all cache_ tables in the database for the website.

Memcache is now enabled for your website. If you need assistance, contact Acquia support.

Allocating memory to Memcached

Acquia Cloud Platform Enterprise

For environments running on Acquia Cloud Next technologies, you can adjust the memory allocated to Memcached by navigating to the Environment Settings page of the Acquia Cloud Platform user interface and selecting the Advanced tab.

For environments running on the Acquia Cloud Classic infrastructure, you must contact Acquia Support to request that your Memcached memory allocation be modified. Larger amounts of memory can be allocated to Cloud Classic environments with dedicated Memcached infrastructure. Contact your Acquia account team for more information about this advanced configuration.

Acquia Cloud Platform Professional

To allocate memory to Memcached on Cloud Platform Professional and enable it to run, use the following procedure:

  1. Sign in to the Cloud Platform user interface and select your application, and then select the environment.

  2. In the left menu, click Servers.

  3. In the card for the web infrastructure, click the Configure link.

    The Cloud Platform user interface displays the Configure link

  4. In the Memcached memory (MB) field, enter the amount of memory to allocate to Memcached. A value of 64 MB is the default value for applications running on Cloud Platform, but you may increase the value depending on the needs of your application.

  5. Click Save.