Install PHP APCu on Plesk

2 minutes read

Install APCu extension on the server

Update the PHP versions to the versions that are required by your system. Using a SSH connection, run the following commands:

On CentOS/AlmaLinux

yum install plesk-php83-devel plesk-php84-devel zlib-devel gcc
/opt/plesk/php/8.3/bin/pecl install apcu
/opt/plesk/php/8.4/bin/pecl install apcu

On Ubuntu

apt update
apt install plesk-php83-dev plesk-php84-dev zlib1g-dev gcc make
/opt/plesk/php/8.3/bin/pecl install apcu
/opt/plesk/php/8.4/bin/pecl install apcu

Enable the APCu PHP module

After installation, the new extension must be enabled. This can be done by using the Plesk UI in Tools & Settings > PHP Settings > php.ini

Plesk UI Screenshot

Add (or uncomment) for the following line :

extension=apcu.so

Restart the web server

Then restart the web servers to make sur that the new configurations have been read:

On CentOS/AlmaLinux

service httpd restart

On Ubuntu

service apache2 restart

Setting APCu cache size

Edit the php.ini file to specify the size of the cache (default is 32M). This can be done by using the Plesk UI in Tools & Settings > PHP Settings > php.ini.

apc.shm_size = 512M

Using APCu with Wordpress

You can use APCu cache in Wordpress to speed up loading time considerably. It will cache Transients in memory (instead of in database), resulting in better loading times. This is possible with W3 Total Cache plugin. Look for the Object Cache settings.

W3 Total Cache screenshot