Switching from MPM Worker to Event with PHP-FPM

Question

CentOS 7, Apache 2.4, FPM/FastCGI, MariaDB

My 512M VPS is eating up memory with one development WordPress site, so I'm hoping this will lead me down a path of better tuning; if not, please inform.

I am attempting to switch from MPM Worker to MPM Event but am receiving the following error upon Apache restart:

AH00526: Syntax error on line 31 of /etc/httpd/conf.d/php.conf:
Invalid command 'php_value', perhaps misspelled or defined by a module not included in the server configuration

/etc/httpd/conf.modules.d/00-mpm.conf

# Select the MPM module which should be used by uncommenting exactly
# one of the following LoadModule lines:

# prefork MPM: Implements a non-threaded, pre-forking web server
# See: http://httpd.apache.org/docs/2.4/mod/prefork.html
#LoadModule mpm_prefork_module modules/mod_mpm_prefork.so

# worker MPM: Multi-Processing Module implementing a hybrid
# multi-threaded multi-process web server
# See: http://httpd.apache.org/docs/2.4/mod/worker.html
#
#LoadModule mpm_worker_module modules/mod_mpm_worker.so

# event MPM: A variant of the worker MPM with the goal of consuming
# threads only for connections with active processing
# See: http://httpd.apache.org/docs/2.4/mod/event.html
#
LoadModule mpm_event_module modules/mod_mpm_event.so

vhost:

<VirtualHost *:80>

    ServerName localhost

    ProxyPassMatch ^/(.*\.php(/.*)?)$ unix:/var/run/php-fpm/php-fpm.sock|fcgi://127.0.0.1:9000/var/www/html

    DocumentRoot /var/www/html
    <Directory /var/www/html>
        Options All -Indexes
        AllowOverride All
        Require all granted
    </Directory>

    ErrorLog /var/log/httpd/localhost_error.log
    CustomLog /var/log/httpd/localhost_access.log combined

</VirtualHost>

/etc/httpd/conf.d/php.conf

#
# Cause the PHP interpreter to handle files with a .php extension.
#
<FilesMatch \.php$>
    SetHandler application/x-httpd-php
</FilesMatch>

#
# Allow php to handle Multiviews
#
AddType text/html .php

#
# Add index.php to the list of files that will be served as directory
# indexes.
#
DirectoryIndex index.php

#
# Uncomment the following lines to allow PHP to pretty-print .phps
# files as PHP source code:
#
#<FilesMatch \.phps$>
#    SetHandler application/x-httpd-php-source
#</FilesMatch>

#
# Apache specific PHP configuration options
# those can be override in each configured vhost
#
php_value session.save_handler "files"
php_value session.save_path    "/var/lib/php/session"

Solution

Found that I needed to make the final lines of my php.conf conditional.

<IfModule mpm_prefork_module>
#
# Apache specific PHP configuration options
# those can be override in each configured vhost
#
php_value session.save_handler "files"
php_value session.save_path "/var/lib/php/session"
</IfModule>

Comments

[mustafa]

what if you really need these values? There must be another solution to set these variables

[Nemo]

The usual recommendation is to move them to php.ini, I believe.