Integrating APC (Alternative PHP Cache) Into PHP5 (Fedora 8 & Apache2)

Version 1.0
Author: Falko Timme

This guide explains how to integrate APC (Alternative PHP Cache) into PHP5 on a Fedora 8 system (with Apache2). APC is a free and open PHP opcode cacher for caching and optimizing PHP intermediate code. It's similar to other PHP opcode cachers, such as eAccelerator and XCache.

I do not issue any guarantee that this will work for you!


1 Preliminary Note

I have tested this on a Fedora 8 server with the IP address where Apache2 and PHP5 are already installed and working. I'll use Apache's default document root /var/www/html in this tutorial for demonstration purposes. Of course, you can use any other vhost as well, but you might have to adjust the path to the info.php file that I'm using in this tutorial.


2 Checking PHP5's Current State

First, before we install APC, let's find out about our PHP5 installation. To do this, we create the file info.php in our document root /var/www/html:

vi /var/www/html/info.php

Afterwards, we call that file in a browser:

As you see, we have PHP 5.2.4 installed...

... but APC isn't mentioned anywhere on the page:


3 Installing APC

APC is a PHP extension that can be installed using PECL. PECL comes with the php-pear package, so we install that now:

yum install php-pear

Furthermore we must install some APC dependencies so that PECL can build APC:

yum install php-devel httpd-devel
yum groupinstall 'Development Tools'
yum groupinstall 'Development Libraries'

Now that all dependencies are installed, we can install APC as follows:

pecl install apc

[[email protected] ~]# pecl install apc
downloading APC-3.0.18.tgz ...
Starting to download APC-3.0.18.tgz (115,957 bytes)
.........................done: 115,957 bytes
47 source files, building
running: phpize
Configuring for:
PHP Api Version:         20041225
Zend Module Api No:      20060613
Zend Extension Api No:   220060519
 1. Use apxs to set compile flags (if using APC with Apache)? : yes

1-1, 'all', 'abort', or Enter to continue: 


Libraries have been installed in:

If you ever happen to want to link against installed libraries
in a given directory, LIBDIR, you must either use libtool, and
specify the full pathname of the library, or use the `-LLIBDIR'
flag during linking and do at least one of the following:
   - add LIBDIR to the `LD_LIBRARY_PATH' environment variable
     during execution
   - add LIBDIR to the `LD_RUN_PATH' environment variable
     during linking
   - use the `-Wl,--rpath -Wl,LIBDIR' linker flag
   - have your system administrator add LIBDIR to `/etc/'

See any operating system documentation about shared libraries for
more information, such as the ld(1) and manual pages.

Build complete.
Don't forget to run 'make test'.

running: make INSTALL_ROOT="/var/tmp/pear-build-root/install-APC-3.0.18" install
Installing shared extensions:     /var/tmp/pear-build-root/install-APC-3.0.18/usr/lib/php/modules/
running: find "/var/tmp/pear-build-root/install-APC-3.0.18" -ls
1996900    4 drwxr-xr-x   3 root     root         4096 Apr  8 16:32 /var/tmp/pear-build-root/install-APC-3.0.18
1996959    4 drwxr-xr-x   3 root     root         4096 Apr  8 16:32 /var/tmp/pear-build-root/install-APC-3.0.18/usr
1996960    4 drwxr-xr-x   3 root     root         4096 Apr  8 16:32 /var/tmp/pear-build-root/install-APC-3.0.18/usr/lib
1996961    4 drwxr-xr-x   3 root     root         4096 Apr  8 16:32 /var/tmp/pear-build-root/install-APC-3.0.18/usr/lib/php
1996962    4 drwxr-xr-x   2 root     root         4096 Apr  8 16:32 /var/tmp/pear-build-root/install-APC-3.0.18/usr/lib/php/modules
1996958  432 -rwxr-xr-x   1 root     root       435950 Apr  8 16:32 /var/tmp/pear-build-root/install-APC-3.0.18/usr/lib/php/modules/

Build process completed successfully
Installing '/usr/lib/php/modules/'
install ok: channel://
configuration option "php_ini" is not set to php.ini location
You should add "" to php.ini
[[email protected] ~]#

Now that APC is installed, we create the configuration file /etc/php.d/apc.ini. We must at least add the line in there; all other configuration options are optional. You can find a list of all available configuration options on

vi /etc/php.d/apc.ini

That's it. Restart Apache, and you're done:

/etc/init.d/httpd restart

Afterwards, open info.php again in a browser:

You should now see APC mentioned on the page which means it has successfully been integrated and is working as expected:


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5 Comment(s)

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By: Tierno Bah

Your step-by-step guide is right on the money. Even thoug my server is quite capable of displaying file upload progress using APC RFC1867, my Drupal configuration was complaining about the lack of uploadprogress. Luckily, I found your howto page. I'am glad I did.

Upon restarting Apache on Linux/Fedora 10 (apachectl graceful), everything is OK.

Thanks for taking the time to put this help file together.

By: Martin X. Moleski, SJ

I'm a new root admin slowly climbing a LOT of learning curves.

First, I can't thank you and all of the other open source or free software packages enough. You are absolutely amazing people!

This tutorial worked splendidly.

Two quirks for me:

1. When I first set up the server, php.ini was in /etc. Then I cooked up my own version of PHP and the new location of the active php.ini file changed to /opt/php5/lib/php.ini. I was pounding away at etc/php.ini with no results. :o(

2. Even though the active php.ini file says that dynamic extensions are loaded automatically if they have an .ini file in /etc/php.d, and even though I put an apc.ini in that folder, APC did not get loaded. I had to get the right php.ini file and add the line from the make output ( Then I got the expected result from phpinfo.php.

Linux 2.6.24-19-xen #1 SMP Sat Jul 12 00:15:59 UTC 2008 x86_64
PHP Version 5.2.8
Server version: Apache/2.2.9 (Unix)


Marty (nearly clueless newbie)
"It is good to be root"

By: Jay Daugherty

Worked fine and dandy for me, too... thanks much for taking the time to do it... my system seemed to hang when running the transaction test portion of the install when groupinstalling the Development Libraries, but I just let it run and eventually it finished.

 Thanks again!

By: Kit Barker

Thanks for taking the time to post this.

 It saved me a lot of time!

By: Anonymous

Great post, very helpful.
Thank you so much.