Using a benchmarking tool to test the limits of your apache server will help you prepare for upgrades.
cPanel adds in an exclusion for all packages named httpd* (any files starting with httpd) to prevent accidentally overwriting apache.
SSH into your server.
Edit /etc/yum.conf and remove the entry httpd* from the Exclude line
vi /etc/yum.conf exclude=bind-chroot courier* dovecot* exim* filesystem httpd* mod_ssl* mydns* mysql* nsd* php* proftpd* pure-ftpd* spamassassin* squirrelmail*
Once the entry has been removed, save the config file and exit.
Run the following command to install ab.
yum install httpd-tools
Make sure to go back into the /etc/yum.conf and add httpd* back to the exclude list, otherwise you risk breaking your cpanel installation.
SSH into your server (or if you are using a desktop open a terminal)
Run the following command to install ab.
sudo apt-get install apache2-utils
Once you have the program installed, you can run a stress test against a domain name.
WARNING: Do not use this against a site you do not control as it will be considered an attack.
Here is an example of a stress test that will simulate 100 users simultaneously making accessing a website.
ab -c 100 -n 100 -r http://example.com/
You can check the manual for ab to find out more information about it's options.