Comments on: APC Cache Considerations for Virtual Hosting Environments

By: Chris Gilligan

Chris Gilligan — Tue, 13 May 2014 14:10:50 +0000

In reply to Albert. benchmarks for mod_php vs mod_fcgid

By: Albert

Albert — Tue, 13 May 2014 11:29:17 +0000

I see how this can be used on a small scale with fewer accounts. Do you know of any server benchmarks for mod_php vs mod_fcgid?

By: Chris Gilligan

Chris Gilligan — Fri, 09 Mar 2012 16:11:41 +0000

In reply to dave.

Dave, you are correct about the filename conflicts. I’ve removed that paragraph. I did have some issues that appeared to be due to cross-account caching.

I also agree that FastCGI consumes more memory than mod_php. However, my servers have plenty of RAM and few virtual domains and are optimized for speed instead of number of clients.

For my needs, servers & clients, and ease of use, APC + mod_fcgid makes sense, and in my experience it is fast and stable. I formerly deployed eAccelerator or Xcache with mod_php, but I prefer fcgid on my current deployed servers. I prefer to tweak apc settings per virtual host, and to run scripts as the virtual server owner/user for ease of administration and allocation of resources.

I don’t have hundreds or thousands of virtual hosts on my servers, just 10 or so per server, and some sites require different php extensions, so in my case it does make sense to run fcgid and have separate php.ini files for each virtual domain.

I have not yet used the mod_php and htaccess method, but will try it on a testbed to see if it provides any benefits.

I would be interested to see objective benchmarks for servers running APC and multiple WordPress installations for mod_php vs mod_fcgid.

By: dave

dave — Thu, 08 Mar 2012 19:02:49 +0000

THIS IS ALL REALLY BAD ADVICE… you really shouldn’t be running PHP as FCGID unless you absolutely have to (mod_php is faster). If someone is thinking about using APC to speed up their pages, they definitely should NOT switch to FCGID just so they can use APC. That would just make their server SLOWER. (Whether they use Virtualmin to do that or if you configure it manually, either way it’s the same thing, and it’s a bad idea).

The “conflicts if scripts are named the same” problem does not exist. (APC caches based on the full file path).

When running a shared virtual server with mod_php, you can install APC, but configure how it is used for each server using .htaccess and setting APC flags, such as filters. Google “apc htaccess” for info on how to do this properly.