1. install php apc
yum install php-pear
yum install php-devel
yum install httpd-devel
yum install gcc
yum install make
yum install pcre-devel
pecl install apc
echo "extension=apc.so" > /etc/php.d/apc.ini
/etc/init.d/httpd restart
2. Install PHP extension for Memcache:
3. Install PHP extension for Memcached
yum install libmemcached-devel
yum install php-pecl-memcached
add zend.enable_gc = 1 into php.ini