How To Install Memcached on Ubuntu 16.04

## Overview

Overview  

Memcached (pronounced: mem-cash-dee) is a free, high performance, distributed memory object caching system.

Memcached can be use for any caching usage but mostly used by dynamic web application to reduce database load. We can also cache API calls and page rendering.

In this tutorial we’ll learn how to install Memcached on Ubuntu 16.04 (LTS) Xenial Xerus. Previously we already learn [how to install memcached on Ubuntu 14.04][1]

Prerequisites  

This tutorial assumes you have a fresh install of Ubuntu server 16.04. You can also follow this tutorial on any Ubuntu 16.04 flavors. Using Ubuntu server will give minimalist installation of Ubuntu.

Install Memcached  

Let’s update our base system to latest update using command below.

sudo apt-get update
sudo apt-get upgrade

Install memcached by running command below

sudo apt-get install memcached

That’s it, memcached installed. Now let’s check whether memcached already started and listen to specific port.

Run netstat and find memcached process.

$ sudo netstat -naptu | grep memcached
tcp        0      0 127.0.0.1:11211         0.0.0.0:*               LISTEN      3125/memcached  
udp        0      0 127.0.0.1:11211         0.0.0.0:*                           3125/memcached  

Or we can also run run netstat and find memcached default port 11211

$ sudo netstat -naptu | grep 11211
tcp        0      0 127.0.0.1:11211         0.0.0.0:*               LISTEN      3125/memcached  
udp        0      0 127.0.0.1:11211         0.0.0.0:*                           3125/memcached

We can also use ss as replacement of netstat to check where memcached listen.

ss -4n state listening | grep 11211
tcp    0      128    127.0.0.1:11211                      *:*

We can check memcached service status by running command below. This is sysv compatible service command.

ubuntu@ubuntu-xenial:~$ sudo service memcached status
● memcached.service - memcached daemon
   Loaded: loaded (/lib/systemd/system/memcached.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2017-10-09 02:24:57 UTC; 53s ago
 Main PID: 2351 (memcached)
   CGroup: /system.slice/memcached.service
           └─2351 /usr/bin/memcached -m 64 -p 11211 -u memcache -l 127.0.0.1

Oct 09 02:24:57 ubuntu-xenial systemd[1]: Started memcached daemon.

Since Ubuntu 16.04 already use systemd, we can also systemctl command to check memcached service status.

$ sudo systemctl status memcached
● memcached.service - memcached daemon
   Loaded: loaded (/lib/systemd/system/memcached.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2017-10-09 02:24:57 UTC; 1min 4s ago
 Main PID: 2351 (memcached)
   CGroup: /system.slice/memcached.service
           └─2351 /usr/bin/memcached -m 64 -p 11211 -u memcache -l 127.0.0.1

Oct 09 02:24:57 ubuntu-xenial systemd[1]: Started memcached daemon.

Configuring Memcached  

Now we have memcached running let’s learn how to configure memcached. Memcached comes with two configuration files.

• /etc/default/memcached
• /etc/memcached.conf

We can enable or disable memcached on boot by changing parameter on /etc/default/memcached file. The default value on this file is

ENABLE_MEMCACHED=yes

To disable memcached on boot we need to change the line above to

ENABLE_MEMCACHED=no

Now let’s check /etc/memcached.conf configuration file.

Memcached Logging on Ubuntu 16.04  

Memcached’s logging directive is skipped by systemd-memcached-wrapper. This script located in /usr/share/memcached/scripts/systemd-memcached-wrapper. In this scipt you can find line: