Simon Holywell

Installing APC and Memcached for PHP Sessions on Redhat

Installing APC on Redhat is as simple as:

[user@server directory]# yum install php-pecl-apc

APC should now be ready to run on your server.  Try running the following command to verify it is setup; you should get something in response like mine:

[user@server directory]# php -r ‘phpinfo();’ | grep ‘apc’
apc
MMAP File Mask => /tmp/apc.s5jA6w
apc.cache_by_default => On => On
apc.coredump_unmap => Off => Off
apc.enable_cli => On => On
apc.enabled => On => On

<…SNIP…>

Now lets move onto installing Memcached, which again is very simple:

[user@server directory]# yum install memcached
[user@server directory]# /etc/init.d/memcached start

The PHP Memcached module can be installed through YUM as well:

[user@server directory]# yum install php-pecl-memcache

Now to configure PHP to use Memcached to store the session information we need to edit our /etc/php.d/memcache.ini file and jump to the bottom of the file where we uncomment the following lines by removing the preceeding semicolon (‘;’):

; Options to use the memcache session handler

; Use memcache as a session handler
;session.save_handler=memcache
 ; Defines a comma separated of server urls to use for session storage
;session.save_path=”tcp://localhost:11211?persistent=1&weight=1&timeout=1&retry_interval=15″

So that it now looks like this:

; Options to use the memcache session handler

; Use memcache as a session handler
session.save_handler=memcache
 ; Defines a comma separated of server urls to use for session storage
session.save_path=”tcp://localhost:11211?persistent=1&weight=1&timeout=1&retry_interval=15″

That just leaves us to restart the Apache/HTTPd process:

[user@server directory]# /etc/init.d/httpd restart

You are now up and running with Memcached PHP sessions and APC served PHP.