How to force reloading php.ini file?

To force a reload of the php.ini you should restart apache.

Try sudo service apache2 restart from the command line. Or sudo /etc/init.d/apache2 restart

TL;DR; If you're still having trouble after restarting apache or nginx, also try restarting the php-fpm service.

The answers here don't always satisfy the requirement to force a reload of the php.ini file. On numerous occasions I've taken these steps to be rewarded with no update, only to find the solution I need after also restarting the php-fpm service. So if restarting apache or nginx doesn't trigger a php.ini update although you know the files are updated, try restarting php-fpm as well.

To restart the service:

Note: prepend sudo if not root

Using SysV Init scripts directly:

/etc/init.d/php-fpm restart        # typical/etc/init.d/php5-fpm restart       # debian-style/etc/init.d/php7.0-fpm restart     # debian-style PHP 7

Using service wrapper script

service php-fpm restart        # typicalservice php5-fpm restart       # debian-styleservice php7.0-fpm restart.    # debian-style PHP 7

Using Upstart (e.g. ubuntu):

restart php7.0-fpm         # typical (ubuntu is debian-based) PHP 7restart php5-fpm           # typical (ubuntu is debian-based)restart php-fpm            # uncommon

Using systemd (newer servers):

systemctl restart php-fpm.service        # typicalsystemctl restart php5-fpm.service       # uncommonsystemctl restart php7.0-fpm.service     # uncommon PHP 7

Or whatever the equivalent is on your system.

The above commands taken directly from this server fault answer

You also can use graceful restart the apache server with service apache2 reload or apachectl -k graceful. As the apache doc says:

The USR1 or graceful signal causes the parent process to advise the children to exit after their current request (or to exit immediately if they're not serving anything). The parent re-reads its configuration files and re-opens its log files. As each child dies off the parent replaces it with a child from the new generation of the configuration, which begins serving new requests immediately.