Install APC (Alternative PHP Cache) in RHEL/CentOS 6/5 & Fedora 20-12

APC (Alternate PHP Cache) is an free and open source cache for PHP code. The main goal of this module is to provide robust framework for caching and optimizing PHP code.

Install PHP APC in Linux
Install and Enable PHP APC in Linux

The instructions provided here shows how to install and enable APC caching for PHP on RHEL 6.5/6.4/6.3/6.2/6.1/6/5.8/5.6, CentOS 6.5/6.4/6.3/6.2/6.1/6/5.8/5.6 and Fedora 20,19,18,17,16,15,14,13,12 using PECL command to download from the repositories.

Install Dependency Packages for APC

First, we need to install required packages called pecl, phpize and apxs commands, to install APC using YUM package manager tool.

yum install php-pear php-devel httpd-devel pcre-devel gcc make

Install APC Using PECL

Now we have all the needed packages to install APC. Here we use PECL command to install it. Please select default settings when asked.

pecl install apc
Sample Output :
WARNING: channel "" has updated its protocols, use "pecl channel-update" to update
downloading APC-3.1.9.tgz ...
Starting to download APC-3.1.9.tgz (155,540 bytes)
.................................done: 155,540 bytes
54 source files, building
running: phpize
Configuring for:
PHP Api Version:         20090626
Zend Module Api No:      20090626
Zend Extension Api No:   220090626
config.m4:180: warning: AC_CACHE_VAL(PHP_APC_GCC_ATOMICS, ...): suspicious cache-id, must contain _cv_ to be cached
../../lib/autoconf/general.m4:1974: AC_CACHE_VAL is expanded from...
../../lib/autoconf/general.m4:1994: AC_CACHE_CHECK is expanded from...
config.m4:180: the top level
config.m4:180: warning: AC_CACHE_VAL(PHP_APC_GCC_ATOMICS, ...): suspicious cache-id, must contain _cv_ to be cached
../../lib/autoconf/general.m4:1974: AC_CACHE_VAL is expanded from...
../../lib/autoconf/general.m4:1994: AC_CACHE_CHECK is expanded from...
config.m4:180: the top level
Enable internal debugging in APC [no] :
Enable per request file info about files used from the APC cache [no] :
Enable spin locks (EXPERIMENTAL) [no] :
Enable memory protection (EXPERIMENTAL) [no] :
Enable pthread mutexes (default) [yes] :
Enable pthread read/write locks (EXPERIMENTAL) [no] :

Enable APC PHP Extension

Run the following command to enable APC extension in Apache configuration.

echo "" > /etc/php.d/apc.ini

Restart Apache Service for APC

Restart the Apache service to take new changes.

service httpd restart
/etc/init.d/httpd restart

Verify APC Installation

Create a file phpinfo.php in Apache web root directory. For example /var/www/html/phpinfo.php.

# vi /var/www/html/phpinfo.php

Add the following code to it. save and close.


// Show all information, defaults to INFO_ALL


Open any browser and type the following URL. You will see APC enabled configuration similar to below.

PHP APC Extension
PHP APC Configuration Screen

Enable PHP APC administration

To enable APC administration panel, copy the following file.

cp /usr/share/pear/apc.php /var/www/html/

Now open the file apc.php with VI editor.

# vi /var/www/html/apc.php

Now set the username and password in the file apc.php as shown below.

defaults('ADMIN_USERNAME','apc');       // Admin Username
defaults('ADMIN_PASSWORD','Set-Password-Here');  // Admin Password - CHANGE THIS TO ENABLE!!!

Type the following URL in the browser. You will get administration panel of APC.


Some screenshots of APC Administration panel for your reference.

Vies Host Stats
APC View Host Stats
APC View Host Stats Overview
System Cache Entries
APC System Cache Entries
APC System Cache Entries Overview
User Cache Entries
APC User Cache Entries
APC User Cache Entries Overview
APC Login Screen
APC Admin Login
APC Admin Login Screen
APC Version Check
APC Version Check
APC Version Check Overview

Upgrade APC using PECL

To upgrade, just execute following command it will download and upgrade APC.

pecl upgrade apc

Uninstall APC using PECL

If you like to remove it, then simple type the following command to uninstall APC completely from the system.

pecl uninstall apc
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29 thoughts on “Install APC (Alternative PHP Cache) in RHEL/CentOS 6/5 & Fedora 20-12”

  1. Hi Ravi. Thanks for publishing this. I was able to use your instructions to install APC on my server’s default PHP version without a problem. However, I’m running a few other versions of PHP on the same server, and I’d like to use it on one of those, specifically PHP 5.6.35.

    I installed that with Plesk and the path to the php.d directory is /opt/plesk/php/5.6/etc/php.d. I tried placing the apc.ini file there, but that didn’t work. I also tried adding the directive “” directly to that PHPs php.ini file. It’s still not running.

    Do you have any advice to get this working?

    • @James,

      I suggest you to compile APC for your PHP 5.6 version to /opt/plesk/php/5.6/etc/php.d directory.. This is the only solution, I think.

  2. Hello,

    I am working on one of my client’s project which loads up very very slowly. I was going through the possible fix and came across below one but not sure whether this would work or not. Can somebody help?

    How to fix – Page Cache Test (Server Side Caching)

    In order to pass this test, you are advised to use a caching mechanism for your pages. There are three methods which can be used to caching your web pages:

    Alternative PHP caching
    – Alternative PHP Cache (APC) is an open source framework which caches data using intermediate PHP code. Most web programmers who are familiar with the PHP programming language can easily set up Alternative
    PHP Cache for your site.
    – Quickcache is a lightweight page caching solution which was formerly known as jpcache. Quickcache caches the page output rather than compiling the PHP page, making it a superior version of page caching to the Alternative PHP caching. Quickcache can be quickly downloaded from their website and can reduce your page load time up to 80%.
    WP Super Cache
    – If you have a WordPress website, WP Super Cache can be installed within seconds and without no programming knowledge.

    Mary Rax


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