Activate mod_filter in Apache on CentOS

When you install Apache HTTP on CentOS, mod_filter is not enabled by default then if you try to use some of its directives an error like this is raised: "Invalid command 'FilterDeclare', perhaps misspelled or defined by a module not included in the server configuration", so to resolve the above error is enough to add the following line to the httpd.conf.

Install Alternative PHP Cache in CentOS

APC is a cache system which stores compiled PHP code, also allows to store user data allowing the web server to serve a greater number of requests per second, it's a worth noting that a wrong configuration of it can slow the response process, so it is important to adjust the cache parameters until finding the proper performance.