In this how to i will describe how to install memcached on your server with PHP Extension.  memcached is a high-performance, distributed memory object caching system, generic in nature, but intended for use in speeding up dynamic web applications by alleviating database load. My server is running CentOS 5.3 with CPanel.

1) Install memcached.

Enable rpmforge respository to install latest memcached rpm using yum.

For i386 / i686

rpm -Uhv http://apt.sw.be/redhat/el5/en/i386/rpmforge/RPMS/rpmforge-release-0.3.6-1.el5.rf.i386.rpm

For x86_64

rpm -Uhv http://apt.sw.be/redhat/el5/en/x86_64/rpmforge/RPMS//rpmforge-release-0.3.6-1.el5.rf.x86_64.rpm

Use yum to install memcached

yum -y install memcached

As soon as memcached installation completed, edit options for memcached in /etc/sysconfig/memcached to meet your need.

vi /etc/sysconfig/memcached

PORT=”11211″                #define on which port to urn
USER=”nobody”           #same as apache user
MAXCONN=”1024″     #maximum number of connections allowed
CACHESIZE=”64″         #memory used for caching
OPTIONS=”"                   #use for any custom options

Save the file. All options can be seen by using following command

memcached -h

Start memcached

/etc/init.d/memcached start
Starting Distributed memory caching (memcached):           [  OK  ]

to check the running status of memcached

/etc/init.d/memcached status
memcached (pid 6475) is running…

and

netstat -anp | grep 11211
tcp  0  0 :::11211    :::*  LISTEN      6475/memcached
udp 0  0 0.0.0.0:11211  0.0.0.0:* 6475/memcached

2) Install PHP Extension.

Download and install latest stable memcache version from PECL.

cd /usr/src
wget http://pecl.php.net/get/memcache-2.2.5.tgz
tar zxvf memcache-2.2.5.tgz
cd memcache-2.2.5
phpize
./configure
make
make install

memcache.so will be install in php modules directory, now enable memcache.so extension in php.ini

To find out your php.ini location, execute following command

php -i | grep php.ini
Configuration File (php.ini) Path => /usr/local/lib
Loaded Configuration File => /usr/local/lib/php.ini

vi /usr/local/lib/php.ini

extension = “memcache.so”

save the file and restart httpd server.

/etc/init.d/httpd restart

To check is memcache extension loaded in php, execute following command.

php -i | grep memcache
memcache
memcache support => enabled
memcache.allow_failover => 1 => 1
memcache.chunk_size => 8192 => 8192
memcache.default_port => 11211 => 11211
memcache.default_timeout_ms => 1000 => 1000
memcache.hash_function => crc32 => crc32
memcache.hash_strategy => standard => standard
memcache.max_failover_attempts => 20 => 20
Registered save handlers => files user sqlite memcache
PWD => /usr/src/memcache-2.2.5
_SERVER["PWD"] => /usr/src/memcache-2.2.5
_ENV["PWD"] => /usr/src/memcache-2.2.5

This information can also be seen using phpinfo().

If you have question please comment.