Is it possible to upgrade Apache to the latest versions from OS update ?
Parallels Plesk Panel versions 7.x and 8.x uses its own Plesk Apache service that serves Control Panel. Parallels Plesk Panel 9.x uses sw-cp-server for serving Control Panel. System Apache which serves users' websites is a part of the operating system distributive and can be updated freely.
In Parallels Plesk Panel version 7.x it is required to replace file /usr/sbin/suexec manually after upgrading of Apache package. You may use the following commands for to replace:
~# cp /usr/local/psa/suexec/psa-suexec /usr/sbin/suexec
~# chown root:apache /usr/sbin/suexec
~# chmod 4510 /usr/sbin/suexec
Where /usr/local/psa is $PRODUCT_ROOT_D.
NOTE: in Parallels Plesk Panel older than 7.5.4 psa-suexec is placed in /usr/sbin/psa-suexec.
In versions 8.x and 9.x Parallels Plesk Panel places a trigger that replaces suexec after upgrading of Apache package. On CentOS the trigger looks like the following:
cp -f /usr/local/psa/suexec/psa-suexec /usr/sbin/suexec
chown root:apache /usr/sbin/suexec
chmod 4510 /usr/sbin/suexec
In Parallels Plesk Panel 8.x, 9.x it is not required to replace /usr/sbin/suexec after upgrading of Apache package.