Server Monitoring With munin And monit

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Submitted by falko (Contact Author) (Forums) on Thu, 2006-04-20 20:10. :: Monitoring

This is a "copy & paste" HowTo! The easiest way to follow this tutorial is to use a command line client/SSH client (like PuTTY for Windows) and simply copy and paste the commands (except where you have to provide own information like IP addresses, hostnames, passwords,...). This helps to avoid typos.

Server Monitoring With munin And monit

Version 1.0
Author: Falko Timme <ft [at] falkotimme [dot] com>
Last edited 04/20/2006

In this article I will describe how to monitor your server with munin and monit. munin produces nifty little graphics about nearly every aspect of your server (load average, memory usage, CPU usage, MySQL throughput, eth0 traffic, etc.) without much configuration, whereas monit checks the availability of services like Apache, MySQL, Postfix and takes the appropriate action such as a restart if it finds a service is not behaving as expected. The combination of the two gives you full monitoring: graphics that lets you recognize current or upcoming problems (like "We need a bigger server soon, our load average is increasing rapidly."), and a watchdog that ensures the availability of the monitored services.

Although munin lets you monitor more than one server, we will only discuss the monitoring of the system where it is installed here.

This tutorial was written for Debian Sarge, but the configuration should apply to other distributions with little changes as well.

I want to say first that this is not the only way of setting up such a system. There are many ways of achieving this goal but this is the way I take. I do not issue any guarantee that this will work for you!

1 Current Situation

Our system's hostname is server1.example.com, and we have a web site www.example.com on it with the document root /var/www/www.example.com/web.

2 Install And Configure munin

To install munin on Debian Sarge, we do this:

apt-get install munin munin-node

Next, we must edit the munin configuration file /etc/munin/munin.conf. We want munin to put its output into the directory /var/www/www.example.com/web/monitoring, therefore we change the value of htmldir, and we want it to use the name server1.example.com instead of localhost.localdomain in the HTML output, therefore we replace localhost.localdomain with server1.example.com. Without the comments, the changed file looks like this:

vi /etc/munin/munin.conf

dbdir   /var/lib/munin
htmldir /var/www/www.example.com/web/monitoring
logdir /var/log/munin
rundir /var/run/munin

tmpldir /etc/munin/templates

[server1.example.com]
address 127.0.0.1
use_node_name yes

Next we create the directory /var/www/www.example.com/web/monitoring and change its ownership to the user and group munin, otherwise munin cannot place its output in that directory. Then we restart munin:

mkdir -p /var/www/www.example.com/web/monitoring
chown munin:munin /var/www/www.example.com/web/monitoring
/etc/init.d/munin-node restart

Now wait a few minutes so that munin can produce its first output, and then go to http://www.example.com/monitoring/ in your browser, and you see the first statistics. After a few days this could look like this:

(This is just a small excerpt of the many graphics that munin produces...)

3 Password-Protect The munin Output Directory (Optional)

Now it is a good idea to password-protect the directory /var/www/www.example.com/web/monitoring unless you want everybody to be able to see every little statistic about your server.

To do this, we create an .htaccess file in /var/www/www.example.com/web/monitoring:

vi /var/www/www.example.com/web/monitoring/.htaccess

AuthType Basic
AuthName "Members Only"
AuthUserFile /var/www/www.example.com/.htpasswd
<limit GET PUT POST>
require valid-user
</limit>

Then we must create the password file /var/www/www.example.com/.htpasswd. We want to log in with the username admin, so we do this:

htpasswd -c /var/www/www.example.com/.htpasswd admin

Enter a password for admin, and you're done!


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Submitted by terryhobart (registered user) on Fri, 2011-12-02 22:36.
I run mysql as a local service with the port closed. How do I configure monit for that?
Submitted by Bjoern (not registered) on Mon, 2009-02-09 03:05.

Hi there,
 another good monitoring tool in my opinion is Zabbix. Though there are plenty around, this is very interesting:
 http://en.wikipedia.org/wiki/Comparison_of_network_monitoring_systems
 Cheers

Submitted by Anonymous (not registered) on Thu, 2006-06-22 22:08.
hi, i agree that by default that the .htaccess file didn't work on Debian Sarge. Instead i just copied what was in the file to the main configuration (apache2.conf) and enclosed it in a < Directory > container e.g. < Directory /var/www/www.example.com/web/monitoring > AuthType Basic AuthName "Password Required" AuthUserFile /var/www/www.example.com/.htpasswd limit GET PUT POST require valid-user < /limit > < /Directory > and then I follwed the remaining steps to make the .htpasswd file and it worked perfectly! Thanks for the great Howto!
Submitted by Anonymous (not registered) on Tue, 2006-05-09 13:41.
It would be nice if you also provided the links to the official sites of the applications...
Submitted by admin (registered user) on Wed, 2006-05-10 10:37.
Submitted by Anonymous (not registered) on Mon, 2006-05-08 17:21.
Another application that does all this easily is www.bixdata.com. Plus it also runs on windows if you need to monitor that.
Submitted by Anonymous (not registered) on Mon, 2006-05-08 03:52.

Dont you need to get apache to work with this? I had to edit conf.d/xxxx.conf in order to get /monitoring/ to link.

eg.,

Alias /monitoring/ /var/www/www.xxxx.dyndns.org/web/monitoring/
#ScriptAlias /monitoring/ /var/www/www.xxxx.dyndns.org/web/monitoring/
<Directory /var/www/www.xxxx.dyndns.org/web/monitoring/>
Options Indexes MultiViews FollowSymLinks
AllowOverride None
Order allow,deny
Allow from all
</Directory>

</VirtualHost>

Then it worked fine, unless I have missed something???

regards

Submitted by Anonymous (not registered) on Mon, 2010-05-24 19:00.
 Also uncomment the following lines:
 
       AuthUserFile /etc/munin/munin-htpasswd
AuthName "Munin"
AuthType Basic
require valid-user
 
Save and close
 
sudo htpasswd -c /etc/munin/munin-htpasswd admin
 
sudo service apache2 restart
 
 Done!
Submitted by Anonymous (not registered) on Sun, 2006-04-23 20:39.

Excellent, and straightforward tutorial.

Remember that the munin logs are located in /var/log/munin/

It can be a while before new graphs are generated. The default configuration will fail.

Submitted by Anonymous (not registered) on Sun, 2006-04-23 12:42.

Munin works just fine out of the box.

But yo must consider when graphing the cpu temp, it rises by 4C at the time munin is running, on a P3 1GHz.

My workaround is to check cpu temp 1min before munin runs an put into a clear text file :)