Install Munin (Monitoring Tool) on Ubuntu 14.10 (Utopic Unicorn) Server

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Munin the monitoring tool surveys all your computers and remembers what it saw. It presents all the information in graphs through a web interface. Its emphasis is on plug and play capabilities. After completing a installation a high number of monitoring plugins will be playing with no more effort.

Using Munin you can easily monitor the performance of your computers, networks, SANs, applications, weather measurements and whatever comes to mind. It makes it easy to determine "what's different today" when a performance problem crops up. It makes it easy to see how you're doing capacity-wise on any resources.

Munin uses the excellent ?RRDTool (written by Tobi Oetiker) and the framework is written in Perl, while plugins may be written in any language. Munin has a master/node architecture in which the master connects to all the nodes at regular intervals and asks them for data. It then stores the data in RRD files, and (if needed) updates the graphs. One of the main goals has been ease of creating new plugins (graphs).

Before installing munin you need to make sure you have Ubuntu 14.10 LAMP server is installed.

Now proceed with munin server using the following command from your terminal

sudo apt-get install munin

Once the package is installed, you only need to make a few changes to get your installation working.

Configuring Munin server

You need to edit the /etc/munin/munin.conf file

sudo vi /etc/munin/munin.conf

Change the following lines

Change 1

#dbdir /var/lib/munin
#htmldir /var/cache/munin/www
#logdir /var/log/munin
#rundir /var/run/munin

to

dbdir /var/lib/munin
htmldir /var/www/munin
logdir /var/log/munin
rundir /var/run/munin

Change 2

#tmpldir /etc/munin/templates

to

tmpldir /etc/munin/templates

Change 3

the server name on the line localhost.localdomain should be updated to display the hostname, domain name, or other identifier you'd like to use for your monitoring server

# a simple host tree
[localhost.localdomain]
address 127.0.0.1
use_node_name yes

to

[MuninMonitor]
address 127.0.0.1
use_node_name yes

Change 4

You need to edit the munin apache configuration

sudo vi /etc/munin/apache.conf

Change the following line in the starting of the file

Alias /munin /var/cache/munin/www

to

Alias /munin /var/www/munin

and

We also need to allow connections from outside of the local computer for this do the following changes

<Directory /var/cache/munin/www>
Order allow,deny
Allow from localhost 127.0.0.0/8 ::1
Options None

to

<Directory /var/munin/www>
Order allow,deny
#Allow from localhost 127.0.0.0/8 ::1
Allow from all
Options None

you will need to create the directory path that you referenced in the munin.conf file and modify the ownership to allow munin to write to it:

sudo mkdir /var/www/munin

sudo chown munin:munin /var/www/munin

Now you need to restart the munin and apache services using the following commands

sudo service munin-node restart

sudo service apache2 restart

It might take a few minutes to generate the necessary graphs and html files. After about five minutes, your files should be created and you will be able to access your data. You should be able to access your munin details at:

http://yourserver_ip_address/munin

Screenshots

If you get an error message in your browser similar to the following, you need to wait longer for munin to create the files

Forbidden

You don't have permission to access /munin/

Configure Remote Monitoring

Munin can easily monitor multiple servers at once.If you want to monitor remote servers you need to following this procedure.

First you need to install munin client package using the following commands

sudo apt-get install munin-node

Now you need to edit the munin-node.conf file to specify that your monitoring server is allowed to poll the client for information.

sudo vi /etc/munin/munin-node.conf

Search for the section that has the line "allow ^127\.0\.0\.1$". Modify the IP address to reflect your monitoring server's IP address.If your server ip is 172.30.2.100

allow ^\.172\.30\.2\.100$

Save and exit the file

You need to restart the munin client using the following information

sudo service munin-node restart

Now you need to login in to your munin server and edit the munin.conf file

sudo vi /etc/munin/munin.conf

Copy the following section and change the ip address to your remote server client ip address

[MuninMonitor]
address 127.0.0.1
use_node_name yes

to

[MuninMonitor]
address 172.30.2.101
use_node_name yes

Finall you need to restart the apache server using the following command

sudo service apache2 restart

Additional Plugins

The munin-plugins-extra package contains performance checks additional services such as DNS, DHCP, Samba, etc. To install the package run the following command from the terminal

sudo apt-get install munin-plugins-extra

Make sure you have install this package on both the server and node machines.

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