Plesk: Apache-Server / PHP-FPM Tuning

Apache

In the following example, we change the Apache server settings to handle many visitors. To do this, we first run the following command:

apache2ctl -V | grep MPM

There can be two results: Prefork or Event

For Prefork modify the file /etc/apache2/mods-enabled/mpm_prefork.conf as follows:

nano /etc/apache2/mods-enabled/mpm_prefork.conf 

MaxRequestWorkers 400
ServerLimit 400

For Event, we modify the /etc/apache2/mods-enabled/mpm_event.conf file as follows:

nano /etc/apache2/mods-enabled/mpm_event.conf

MaxRequestWorkers 400
ServerLimit 400

Then we restart the Apache2 server:

systemctl restart apache2

Note: Under CentOs the configuration file must be generated first, e.g. with

nano /etc/httpd/conf.modules.d/mpm_event.conf

Restarting the Apache server also works slightly different

systemctl restart httpd.service

PHP-FPM

In the following example we change the PHP settings under Plesk to handle many visitors. First of all, we should make sure that the latest PHP version is used if possible. The execution should be done as FPM by Apache. Also the memory_limit should be chosen appropriately (256M / 512M). opcache.enable should be set to on. pm.max_children to 12 and pm to ondemand. Under additional directives the following can be entered:

opcache.enable=1
opcache.enable_cli=0
opcache.memory_consumption=512
opcache.interned_strings_buffer=32
opcache.max_accelerated_files=16229
opcache.max_wasted_percentage=10
opcache.revalidate_freq=0
opcache.validate_timestamps=1
opcache.revalidate_freq=0
opcache.fast_shutdown=0
opcache.enable_file_override=0
opcache.max_file_size=0
pm.process_idle_timeout=120s

Of course, the opcache module should be installed for this.

mod_pagespeed

Also, mod_pagespeed can be installed on Plesk under Extensions/Extensions. If an error occurs during the installation, the following command must be executed in the SSH console:

apt-get install -y sudo