Memcached is a free, open-source, high-performance, distributed memory object caching system. It is mostly used to speed up the websites by caching data and objects in RAM to reduce the number of times an external data source (such as a database or API) must be read. It runs on Unix, Linux, Windows OS and Mac OS.
It is widely used by most popular websites such as YouTube, Reddit, Zynga, Facebook, Orange, Twitter and Wikipedia etc. In this article, let us setup Memcached on Debian 7 ‘Wheezy’.
Prerequisites
Before installing Memcached, make sure that your server is up-to-date.
Login as root user and perform the steps:
root@server:~# apt-get update root@server:~# apt-get upgrade
In addition, make sure that you have installed the following packages in your server:
root@server:~# apt-get install mysql-server php5-mysql php5 php5-dev php-pear
Install Memcached
Execute the following command to install Memcached:
root@server:~# apt-get install memcached
Now test Memcached service is started and running using the following command:
root@server:~# ps -eaf | grep memcached nobody 7148 1 0 15:09 ? 00:00:00 /usr/bin/memcached -m 64 -p 11211 -u nobody -l 127.0.0.1 root 7186 3190 0 15:13 pts/0 00:00:00 grep memcached
And also check the stats of Memcached using the following command:
root@server:~# echo "stats settings" | nc localhost 11211 STAT maxbytes 67108864 STAT maxconns 1024 STAT tcpport 11211 STAT udpport 11211 STAT inter 127.0.0.1 STAT verbosity 0 STAT oldest 0 STAT evictions on STAT domain_socket NULL STAT umask 700 STAT growth_factor 1.25 STAT chunk_size 48 STAT num_threads 4 STAT num_threads_per_udp 4 STAT stat_key_prefix : STAT detail_enabled no STAT reqs_per_event 20 STAT cas_enabled yes STAT tcp_backlog 1024 STAT binding_protocol auto-negotiate STAT auth_enabled_sasl no STAT item_size_max 1048576 STAT maxconns_fast no STAT hashpower_init 0 STAT slab_reassign no STAT slab_automove no END
Configure Memcached
The default configuration file of Memcached in Debian is /etc/memcached.conf:
root@server:~# nano /etc/memcached.conf
Change the RAM (ex. 128) and other values as per your requirement:
[...] # Start with a cap of 64 megs of memory. It's reasonable, and the daemon default # Note that the daemon will grow to this size, but does not start out holding t$ # memory -m 128 # Default connection port is 11211 -p 11211 [...]
For a best configuration practices, please refer here.
Save and exit the config file. Restart Memcached service to take effect the saved changes:
root@server:~# /etc/init.d/memcached restart
Now check the configuration stats of Memcached again using the following command:
root@server:~# echo "stats settings" | nc localhost 11211 STAT maxbytes 134217728 STAT maxconns 1024 STAT tcpport 11211 STAT udpport 11211 STAT inter 127.0.0.1 [...]
Install PHP-Memcached extension
Run the following command to start installing php-memcached extension:
root@server:~# pecl install memcache
You will see a output like this:
[...] Installing shared extensions: /tmp/pear/temp/pear-build-rootGAjS9y/install-memcache-2.2.7/usr/lib/php5/20100525+lfs/ running: find "/tmp/pear/temp/pear-build-rootGAjS9y/install-memcache-2.2.7" | xargs ls -dils 799913 4 drwxr-xr-x 3 root root 4096 Jul 27 16:20 /tmp/pear/temp/pear-build-rootGAjS9y/install-memcache-2.2.7 799917 4 drwxr-xr-x 3 root root 4096 Jul 27 16:20 /tmp/pear/temp/pear-build-rootGAjS9y/install-memcache-2.2.7/usr 799918 4 drwxr-xr-x 3 root root 4096 Jul 27 16:20 /tmp/pear/temp/pear-build-rootGAjS9y/install-memcache-2.2.7/usr/lib 799919 4 drwxr-xr-x 3 root root 4096 Jul 27 16:20 /tmp/pear/temp/pear-build-rootGAjS9y/install-memcache-2.2.7/usr/lib/php5 799920 4 drwxr-xr-x 2 root root 4096 Jul 27 16:20 /tmp/pear/temp/pear-build-rootGAjS9y/install-memcache-2.2.7/usr/lib/php5/20100525+lfs 798969 236 -rwxr-xr-x 1 root root 241444 Jul 27 16:20 /tmp/pear/temp/pear-build-rootGAjS9y/install-memcache-2.2.7/usr/lib/php5/20100525+lfs/memcache.so Build process completed successfully Installing '/usr/lib/php5/20100525+lfs/memcache.so' install ok: channel://pecl.php.net/memcache-2.2.7 configuration option "php_ini" is not set to php.ini location You should add "extension=memcache.so" to php.ini
Restart the Apache server using the following command:
root@server:~# /etc/init.d/apache2 restart
Now test the Memcached extension:
root@server:~# php -i | grep memcache /etc/php5/cli/conf.d/20-memcached.ini, memcached memcached support => enabled libmemcached version => 1.0.8 memcached.compression_factor => 1.3 => 1.3 memcached.compression_threshold => 2000 => 2000 memcached.compression_type => fastlz => fastlz memcached.serializer => php => php memcached.sess_binary => 0 => 0 memcached.sess_lock_wait => 150000 => 150000 memcached.sess_locking => 1 => 1 memcached.sess_prefix => memc.sess.key. => memc.sess.key. Registered save handlers => files user memcached
That’s it.
