Altering values in settings.php with hooks¶

Conditionally increasing memory limits¶

Certain pages on your websites may require increased memory limits to function properly. To increase the memory limit on your websites, use the following script:

<?php
/**
* Sets a higher memory limit for admin/structure/menu which frequently
* needs an unusually high amount of memory to load, due to complexity.
* For additional examples of changing memory limits for pages on
* your websites, see
* https://support-acquia.force.com/s/article/360004542293-Conditionally-increasing-memory-limits
*/

if (strpos($_GET['q'], 'admin/structure/menu/') === 0) {
   ini_set('memory_limit', '700M');
}

For additional examples, see Examples of conditional memory limit changes.

Enabling memcache¶

To enable memcache on your Site Factory websites:

• Contact your Technical Account Manager or Account Manager to discuss your subscription’s hardware needs.

• Install the Memcache API and Integration module to your codebase.

• Modify the following script to provide the necessary configuration details:

$conf['cache_backends'][] = '<path to the memcache.inc file>';
$conf['cache_default_class'] = 'MemCacheDrupal';
$conf['cache_class_cache_form'] = 'DrupalDatabaseCache';

• For complete information about enabling memcached, see Enabling Memcached on Cloud Platform.

Importing a configuration directory¶

To import configuration values into an Site Factory website, edit the following script to point to the directory (or directories) where your configuration values are stored:

$settings['config_sync_directory'] = 'your/config/sync/directory/path'
$settings['config_vcs_directory'] = 'your/config/vcs/directory/path'

For earlier versions of Drupal 8, use the following code:

<?php
/**
*  Set vcs and sync dirs to writable directories above docroot.
*/
$config_directories['vcs'] = '../config/default';
$config_directories['sync'] = '../config/default';

If the config directory does not already exist, you must create it in the same folder containing your docroot directory, as in this example:

/docroot/
config/default/

Drupal 7 cache lifetime per website¶

To conditionally set the cache lifetime of each website in your Site Factory subscription to individual values, and disallowing any value of fewer than 5 minutes, download this example acsf-cache-lifetime.php script.

New Relic monitoring¶

To enable New Relic monitoring in a multisite environment, like Site Factory, create a post-settings.php script named new_relic.php containing the following code, replacing current_app_name with the name of your application:

if (extension_loaded('newrelic')) {
$env = 'local';

if (isset($_ENV['AH_SITE_ENVIRONMENT'])) {
 $env = $_ENV['AH_SITE_ENVIRONMENT'];
}

global $_acsf_site_name;
newrelic_set_appname("<current_app_name>.$env.$_acsf_site_name; <current_app_name>.$env", '', 'true');
}

Storing credentials outside of version control¶

If you must store sensitive credentials outside of your codebase, you can create a secrets.settings.php file and then make its contents available to Drupal with a post-settings.php hook (as described in Storing sensitive information outside of your codebase). By doing so, sensitive credentials are not kept in your database backups or your version control repository, allowing you to distribute database backups or grant repository access to team members who must not possess sensitive credentials.

Avoiding database deadlocks¶

You can minimize database deadlocks by changing the transaction isolation (tx_isolation) variable from the MySQL default of REPEATABLE-READ to READ-COMMITTED by creating both a pre-settings.php hook script and a post-settings.php hook script.

First, create a pre-settings.php hook script containing the following line:

$conf['acquia_hosting_settings_autoconnect'] = FALSE;

Next, download this example acsf-hook-tx-isolation.php script to create a post-settings.php hook script.

For more information, see Fixing database deadlocks in the Acquia Support Knowledge Base.