APC doesn't cache -> PHP + mod_fastcgi + Apache + suEXEC + CentOS 5.7

Question

I'm having trouble with APC working correctly. I've installed the following packages on my CentOS 5.7 VPS:

• httpd.i386 - 2.2.3-53.el5.centos.3
• php.i386 - 5.2.10-1.el5.centos
• mod_fastcgi.i386 - 2.4.6-1.el5.rf

My /etc/httpd/conf.d/fastcgi.conf file looks like this:

<IfDefine FASTCGI>
LoadModule fastcgi_module modules/mod_fastcgi.so

FastCgiConfig -idle-timeout 20 -maxClassProcesses 1
FastCgiWrapper On

<Location "/cgi-bin/php-fastcgi">
   Order Deny,Allow
   Deny from All
   Allow from env=REDIRECT_STATUS
   Options ExecCGI
   SetHandler fastcgi-script
</Location>

AddHandler php5-fcgi .php
AddType application/x-httpd-php .php
Action php5-fcgi /cgi-bin/php-fastcgi
</IfDefine>

---

Virtualhost for one of the websites looks like this:

<VirtualHost XXX.XXX.XXX.XXX:80>
    ServerName example.com
    ServerAlias www.example.com
    DocumentRoot /home/user/public_html
    ErrorLog logs/example.com-error_log
    CustomLog logs/example.com-access_log common

SuexecUserGroup user user
ScriptAlias /cgi-bin/ "/var/www/cgi-bin/"

<Directory "/home/user/public_html">
    Options +ExecCGI
    AddHandler php5-fastcgi .php
    Action php5-fastcgi /cgi-bin/php.fcgi
    Order allow,deny
    Allow from all
</Directory>

<Directory "/home/user/public_html/cgi-bin">
                AllowOverride None
                Options +FollowSymLinks +SymLinksIfOwnerMatch
                Order allow,deny
                Allow from all
</Directory>

</VirtualHost>

---

And my fastcgi script in /var/www/cgi-bin/php.fcgi looks like this:

#!/bin/sh

PHP_FCGI_CHILDREN=4
export PHP_FCGI_CHILDREN
PHP_FCGI_MAX_REQUESTS=1000
export PHP_FCGI_MAX_REQUESTS

umask 0022
exec /usr/bin/php-cgi

---

APC is configured only with the following directives (everything that is not mentioned, of course, inherits the default values):

extension=apc.so
apc.enabled=1
apc.shm_size=32M
apc.ttl=0
apc.file_update_protection=2
apc.stat=1
apc.rfc1867=1
apc.mmap_file_mask=/tmp/apc.XXXXXX

---

My PHP aplications work without any problems, but APC doesn't do the cacheing. For example, if I access the apc.php file to see the cache stats I can see that APC uptime is on every page refresh only 1 second.

I suppose that cause of this problem would be FastCGI spawning more than one php-cgi process, but there is FastCgiConfig -idle-timeout 20 -maxClassProcesses 1 in fastcgi.conf which should limit spawning to only one process. :-/

Am I missing something or did I maybe misconfigured something?

Edit: I forgot to mention, Apache is running as worker MPM.

Answer 1

You're much better off doing this with PHP-FPM than PHP-CGI.