How to add APC cache to Magento

May 10th, 2012

Warning: This post is 12 years old. Some of this information may be out of date.

The Alternative PHP Cache (APC) is a free and open opcode cache for PHP. It can help speed up your Magento installations.

First, install the PHP APC package (Assuming you are using Ubuntu as your web server):

sudo apt-get install php-apc

Now configure APC for use with Magento. Edit /etc/php5/conf.d/apc.ini:

    extension=apc.so
    apc.enabled = On
    apc.optimization  = 0
    apc.shm_segments = 1
    apc.shm_size = 512
    apc.ttl = 7200
    apc.user_ttl  = 720
    apc.num_files_hint = 1024
    apc.mmap_file_mask = /tmp/apc.XXXXXX
    apc.enable_cli = 1
    apc.cache_by_default  = 1
    apc.max_file_size = 10M
    apc.stat = 0
    #apc.include_once_override = 1

Once you have changed the apc.ini file you will need to restart the Apache Web Server:

service apache2 restart

Finally, configure Magento to use APC: Edit app/etc/local.xml and add the following:

    <global>
        ....
        <cache>
            <backend>apc</backend>
            <prefix>MAGE_</prefix>
        </cache>
    </global>

That's all there is to it. To check that APC is being used you can use the APC.php file as discussed in my post.