When developing applications, there are tasks that are resource-intensive or that do not change during a session. It is important to cache this data.

APCu uses RAM to store data. Configuration information is available here here.

installations :

sudo apt install php8.1-apcu

use:

#Sauvegarde
apcu_store($key_APCu, self::$cacheAPCu, 3600);
#Recuperation des données.
apcu_fetch($key_APCu);

Configuration:
Edit the file : /etc/php/8.1/fpm/conf.d/20-apcu.ini

Tip:
To determine the path to a PHP configuration file, you can display the phpinfo() page. (under Drupal /admin/reports/status/php).