Install APC
yum install php-pear php-devel httpd-devel pcre-devel gcc make pecl install apc
Enable APC
vim /etc/php.d/apc.ini extension=apc.so apc.enabled=1 apc.max_file_size=5M apc.num_files_hint=10000 apc.user_entries_hint=10000 apc.shm_size=256M apc.stat=0 apc.ttl=86400
Setup APC Admin Page
cp /usr/share/pear/apc.php /var/www/vhosts/myhelper/htdocs/apc.php
vim /var/www/vhosts/myhelper/htdocs/apc.php
defaults('ADMIN_USERNAME','myhelper');
defaults('ADMIN_PASSWORD','123456');
Restart Apache
/etc/init.d/httpd graceful
Clear APC Cache
<?php apc_clear_cache(); ?>
Reference:
http://www.agileapproach.com/blog-entry/howto-install-pecl-apc-cache-centos-without-xampp/
http://www.tipsandtutorials.net/centos-6-install-apc.html