Munin ubuntu

The Linode Manager provides some basic monitoring of system resource utilization, which includes information regarding Network, CPU, and Input/Output usage over the last 24 hours and 30 days. While this basic information is helpful for monitoring your system, there are cases where more fine-grained information is useful. For instance, if you need to monitor memory usage or resource consumption on a per-process level, a more precise monitoring tool like Munin might be helpful.

Munin is a system and network monitoring tool that uses RRDTool to generate useful visualizations of resource usage. The primary goal of the Munin project is to provide an easy to use tool that is simple to install and configure and provides information in an accessible web based interface. Munin also makes it possible to monitor multiple “nodes” with a single installation.

Before installing Munin, we assume that you have followed our getting started guide. If you are new to Linux server administration, you may be interested in our introduction to Linux concepts guide, beginner’s guide and administration basics guide. Additionally, you’ll need to install a web server such as Apache in order to use the web interface.

Installing Munin

Make sure your package repositories and installed programs are up to date by issuing the following commands:

The Munin system has two components: a master component often referred to as simply “munin,” and a “node” component, or “munin-node,” which collects the data and forwards it to the master node. In Lucid, you need to install both the and packages if you wish to monitor the Linode you plan to use as the primary Munin device. To install these packages, issue the following command:

On all of the additional machines you administer that you would like to monitor with Munin, issue the following command:

The machines that you wish to monitor with Munin do not need to run Ubuntu. The Munin project supports monitoring for a large number of operating systems. Consult the Munin project’s installation guide for more information installing nodes on additional operating systems.

Configuring Munin

Munin Master Configuration

The master configuration file for Munin is . This file is used to set the global directives used by Munin, as well as the hosts monitored by Munin. This file is large, so we’ve opted to show the key parts of the file. For the most part, the default configuration will be suitable to your needs.

The first section of the file contains the paths to the directories used by Munin. Note that these directories are the default paths used by Munin and can be changed by uncommenting and updating the path. When configuring your web server with Munin, make sure to point the root folder to the path of .

File: /etc/munin/munin.conf

There are additional directives after the directory location block such as , which shows Munin where to look for HTML templates, and others that allow you to configure mail to be sent when something on the server changes. These additional directives are explained more in depth on the munin.conf page of the Munin website. You can also find quick explanations inside the file itself via hash () comments. Take note that these global directives must be defined prior to defining hosts monitored by Munin. Do not place global directives at the bottom of the file.

The last section of the file defines the hosts Munin retrieves information from. For a default configuration, adding a host can be done in the form shown below:

File: /etc/munin/munin.conf

For more complex configurations, including grouping domains, see the comment section in the file, reproduced below for your convenience:

File: /etc/munin/munin.conf

Munin Node Configuration

The default file contains several variables you’ll want to adjust to your preference. For a basic configuration, you’ll only need to add the IP address of the master Munin server as a regular expression. Simply follow the style of the existing line if you’re unfamiliar with regular expressions.

File: /etc/munin/munin-node.conf

The above line tells the munin-node that the master Munin server is located at IP address . After updating this file, restart the . In Ubuntu, use the following command:

Web Interface Configuration

You can use Munin with the web server of your choice, simply point your web server to provide access to resources created by Munin. By default, these resources are located at .

If you are using the Apache HTTP Server you can create a Virtual Host configuration to serve the reports from Munin. In this scenario, we’ve created a subdomain in the DNS Manager and are now creating the virtual host file:

File: /etc/apache2/sites-available/stats.example.org

If you use this configuration you will want to issue the following commands to ensure that all required directories exist, and that your site is enabled:

Now restart the server so that the changes to your configuration file can take effect. Issue the following command:

You should now be able to see your site’s statistics by appending to the end of your IP address (e.g. .) If you don’t see any statistics at first, be sure to wait for Munin to update; Munin refreshes every 5 minutes.

In most cases you will probably want to prevent the data generated by Munin from becoming publicly accessible. You can either limit access using rule based access control so that only a specified list of IPs will be permitted access, or you can configure HTTP Authentication to require a password before permitting access. You may want to examine Munin’s example Apache configuration file at . In addition to protecting the virtual host, also ensure that the munin controls are also protected on the default virtual host (e.g. by visiting where is the IP address of your server.)

More Information

You may wish to consult the following resources for additional information on this topic. While these are provided in the hope that they will be useful, please note that we cannot vouch for the accuracy or timeliness of externally hosted materials.

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monitoringubuntu

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Introduction

Munin is a system, network, and infrastructure monitoring application that provides information in graphs through a web browser. It is designed around a client-server architecture and can be configured to monitor the machine it’s installed on (the Munin master) and any number of client machines, which in Munin parlance, are called Munin nodes.

In this article, we’ll install and configure Munin to monitor the server it’s installed on and one node. To install Munin on multiple nodes, just follow the instructions for creating a node on each system.

Prerequisites

• Two Ubuntu 14.04 Droplets. One of the servers will be the Munin master. The other will be the Munin node.
• For each Droplet, a non-root user with sudo privileges

All the commands in this tutorial should be run as a non-root user. If root access is required for the command, it will be preceded by . Initial Server Setup with Ubuntu 14.04 explains how to add users and give them sudo access.

Step 1 — Installing Required Packages

We will start working on the Munin master first. Before installing Munin, a few dependencies need to be installed.

Though Munin can function with most popular Web servers like Nginx and Lighttpd, it is, by default, designed to work with the Apache Web server. So be sure that Apache is installed and configured on the Munin master. If it’s not already installed, do so using:

To ensure that the dynazoom functionality, which is responsible for zooming into the generated graphs, work properly on click, install the following:

After installing those two packages, the module should be enabled. To double-check, type:

The output should be:

If the output is blank, then it’s not enabled. You may then enable it using:

When executing the command, you can ignore the following warning:

Apache will still work with Munin with this warning.

The rest of the configuration that will make graph zooming work properly will be covered in Step 3.

Step 2 — Installing Munin on the Munin Master

Installation packages for Munin are available in the official Ubuntu repository, so they can be installed using the distribution’s package manager. In this step, you’ll install the Munin master package. The version in the repository is the latest stable release.

To install it to monitor the server it’s installed on, type:

Step 3 — Configuring the Munin Master

Munin’s main configuration file and other files required for it to function are in the directory and its sub-directories. In this step, we’ll modify the main configuration file for the Munin master and its Apache configuration .

The main configuration file is made up of at least two sections — a global and at least one host section. Optionally, there can be a group section. Host and group sections start with their respective names in square brackets. This file contains variable definitions, directives that govern how Munin monitors servers and services, and which servers to monitor.

To begin, open the main configuration file:

Look for these lines and uncomment them — remove the # sign that precedes them. The dbdir stores all of the rrdfiles containing the actual monitoring information; htmldir stores the images and site files; logdir maintains the logs; rundir holds the state files; and tmpldir is the location for the HTML templates. Be sure to change the htmldir from to your web directory. In this example, we’ll be using :

/etc/munin/munin.conf

Since the does not exist, let’s create and chown it so that it’s owned by the system user:

Finally, in , look for the first host tree. It defines how to access and monitor the host machine. It should read:

/etc/munin/munin.conf

Change the name of that tree to one that uniquely identifies the server. This the name that will be displayed in the Munin web interface. In this example, we’ll be using MuninMaster, but you could also use the server’s hostname:

/etc/munin/munin.conf

That’s all for the configuration file, so save and close it.

Within the same directory, the next file we’ll be modifying is , which is Munin’s Apache configuration file. It is sym-linked to , which, in turn, is sym-linked to . To start modifying it, open it with :

At the very top of the file, modify the first line so that it reflects the htmldir path you specified in and created previously. Based on the directory path used in this article, it should read as follows, which makes it so you can access Munin’s web interface by appending munin to the server’s IP address or domain hosted on the server:

/etc/munin/apache.conf

Next, look for the Directory section, and change the directory to . Also comment out (or delete) the first four lines and then add two new directives so that it reads:

/etc/munin/apache.conf

Look for the penultimate location section, comment out or delete the first two lines and add two new ones so that it reads:

/etc/munin/apache.conf

Do the same to the last location section:

/etc/munin/apache.conf

Save and close the file. Then restart Apache and Munin.

You may now access Munin’s web interface by pointing your browser to server-ip-address/munin

Step 4 — Adding a Node to Munin Master

In this step, we’ll show how to add a remote server (or node) to the Munin master so that you can monitor it within the same web interface. This involves modifying the Munin master’s configuration file to specify a host tree for the node. Then, you will need to install the Munin node package on the node and modify its configuration file so that it can be monitored by the Munin master.

Let’s start with the Munin node — the second Ubuntu Droplet you created.

Log into the Munin node, update the package database and install the Munin node package:

After the installation has completed successfully, the node’s configuration file should be in the directory. Open it with :

Towards the middle of the file, look for an allow ^127.0.0.1$ line and modify it so that it reflects the IP address of the Munin master. Note that the IP address is in regex format, so assuming that the master server’s IP address is 123.46.78.100, the line should read as follows:

Save and close the file. Then restart the Munin:

Back on the Munin master, open the main configuration file:

All we need to do in this file is insert a host tree for the (remote) node. The easiest approach to that is to copy and modify the host tree of the master. Be sure to replace node-ip-address with the IP address of the node you are adding:

/etc/munin/munin.conf

Save and close the file. Then restart Apache:

Munin checks for new nodes every 5 minutes. Wait a few minutes, and then reload the Munin master’s web interface. You should see an entry for the node. If you don’t see it yet, try again in 5 minutes. Using this method, you may add as many nodes as you have to monitor.

Munin monitors a system using plugin scripts, and by default, about a dozen set of plugins are installed and active. A complete list of available plugins are in the directory. To see which plugins can be used on your system, Munin provides the following command:

The output should be of this sort:

A plugin with a yes in the Used column means just what it indicates, while one with a yes in the Suggestions column means it can be used. One with a no on both columns means it is not in use and cannot be used on the system. Finally, if a plugin has a no in the Used column and a yes in the Suggestions, then it is not being used but can be enabled and used on the system.

On the Munin master and node, you can also see a list of installed plugins in the directory.

A package should have been installed when you installed Munin. If it was not, do so using.

To enable an available plugin that’s not currently in use, create a symbolic link for it from the directory to the directory.

For example, to enable the Fail2ban plugin, first install Fail2ban:

Then, create the symlink that enables the Munin plugin:

Restart Munin:

Wait a few minutes, reload the web interface, and you should see graphs for Fail2ban under the title Hosts blacklisted by fail2ban under the network category for the Munin master.

Troubleshooting

If you are having trouble configuring the Munin master, the Munin node, or getting the master to see the node, check out the log files for error messages:

• Munin master:
• Munin node:

You can also check the project’s page for additional troubleshooting tips.

Conclusion

Munin can be configured to monitor the system on which it is installed. Adding remote servers to the monitored system is as simple as install the package on the remote server (or node) and then modifying the server’s and node’s configuration files to point to the other IP address.

Munin works by using plugins, but not all are enabled out of the box. Information about plugins are available on the project’s page.

Hello, friends. In this post, you will learn how to install Munin Agent on Ubuntu 20.04. Of course, we will also add it to the server so that it can monitor it.

In the previous post, you learned how to install Munin on Debian 10. That installation referred to the server-side. Note that Munin monitors especially remote machines. Now I will show you how to install the agent or client on an Ubuntu 20.04 machine so that the client is handled by the server. The procedure is quite simple and practical.

Install Munin Agent on Ubuntu 20.04

Before we start, you have to know that we are working on two servers. The first one is where we have the Munin server which contains Debian 10. The other one is the client.

Have at hand the IP addresses and hostname of each of them and open the port 4949 on both.

So, on the client, open a terminal session and update Ubuntu.

After that, you need to install the munin-node package which is the package where the Munin client is embedded.

This package is available in the official Ubuntu repositories so the installation is not complex.

So, install the package by running:

this way it will be installed.

Adding the Munin client to the server

On the client-side, we now have to configure the machine to communicate with the server.

To do this, edit the munin configuration file

And at the end of the file, add the following content:

Remember to change the hostname to the client’s hostname and the client’s IP address. Do not modify the symbols or which are necessary.

Save the file and close it.

Apply the changes by restarting the service.

And check the status of the service:

Working on the server

We are almost ready, but we have to adjust some things on the server.

On the server, open the munin configuration file.

And add the following information

Remember that you have to change the hostname and the IP address to the client’s one. This is done so that the program can monitor it.

Apply the changes by restarting the munin services.

Now we are ready.

Now open a web browser and access the Munin server and you should see the client node already added.

Munin is a comprehensive software for monitoring computers, especially servers. It helps the system administrators to collect various system information that can be viewed via a web interface such as processor load, hard disk usage, network traffic, access to server services on one or more computers, and more…

It is suitable for monitoring a single server or a large number of servers. Munin itself is set up as a master/client application. If there are several machines to be monitored then the server with Munin main instance act as a Master, the information from all machines is collected and evaluated on this; whereas other servers or machine will be known as nodes, that only collect data on the local machine and make it available to the master.

The master computer can query the “Munin node” on other computers in the network and thus display the information. Munin is therefore suitable for monitoring a single computer as well as for monitoring an entire computer network. If you are looking for Munin open-source alternatives then Nagios and Icinga are some of them.

Steps to Munin Monitoring on Ubuntu 20.04 LTS Linux

1. Switch to root user

Open command terminal or access the server via SSH. And then switch to root user for installing and setup the Munin Server monitoring solution.

2. Run Ubuntu system update

Before moving further let’s first run the system update command to refresh the system repository cache and install a new available version of the existing packages on the system.

3. Install Apache and some other dependencies

We need to configure a web server on Ubuntu to access the web interface over a network of Munin. Therefore, use the below-given command to install Apache and other required packages.

4. Command to Install Munin on Ubuntu 20.04 Server

Munin can be installed from package sources on Ubuntu, hence we don’t need to add any additional or extra repository on our system.

The above command will install Munin, Munin-node, and Munin plugins extra.

If your server or the remote server that you want to monitor also has Mysql or MariaDB database then to monitor it also enables few extra Munin plugins.

Also, enable logs and other directories required to store data generated by Munin.

Edit Munin configuration file:

In the file delete the # symbol given in front of the following lines to uncomment them. For more information, you can see the screenshot.

To save the file press Ctrl+O, press the Enter key, and then Ctrl+X to exit the file.

5. Configure Apache for Munin Server monitoring

We already have a pre-build Apache configuration file for Munin inside its directory, hence, just create a Symbolic link of that file for Apache.

Go to Apache configuration directory.

Create Symbolic Link 

(optional) If you want to access the Munin Web interface outside your localhost, which means the server where you have installed this Server monitoring tool, then edit the Munin Apache configuration file.

Now, add the # symbol in front of the line “” and after that add

And also change the value from None to

See the below screenshot to get an idea. Whereas to save the file press Ctrl+O, press the Enter key, and then Ctrl+X to exit the file.

Restart Apache:

Restart Munin service

To check the status

6. Access Munin Server Web interface

Now, open a local or remote browser and point it to your Munin server IP-address along with a directory of it. For example:

Change Server-IP address with the actual address or domain name of your server.

7. Setup Node to monitor multiple systems

If you want to monitor remote Linux systems then first install Munin node in that:

After that edit the Node configuration file:

Add the Master Munin Server IP address where you want to collect the stats of the node system. In the below format.

For example, our master server ip-address is 192.168.0.108. So the format will be like this:

Restart node service

Now, go to Master Munin Server and add the node Ip-address there in its configuration file that you want to monitor there.

Add the Node Address in the below format:

Change the address and domain values as per yours in the above format.

Save the file Crtrl+O, press Enter key, and to exit use Ctrl+X.

Reload Munin:

Now, on your Munin Web interface you will have the added Node:

Munin is an excellent system monitoring tool similar to RRD tool which will give you ample information about system performance in multiple fronts like disk, network, process, system and users. These are some of the default properties Munin monitors.

How Munin works?

Munin works in a client-server model. Munin server process on main server try to collect data from client daemon which is running locally(Munin can monitor its own resources) or from remote client(Munin can monitor hundreds of machines) and displays them in graphs on its web interface.

Configuring Munin in nutshell

This is of two steps as we have to configure both server and client.

1)Install Munin server package and configure it so that it get data from clients.

2)Configure Munin client so that server will connect to client daemon for data collocation.

Install Munin server in Linux

Munin server installation on Ubuntu/Debian based machines

# apt-get install munin apache2

Munin server installation on Redhat/Centos based machines. Make sure that youenable EPEL repo before installing Munin on Redhat based machines as by default Redhat based machines do not have Munin in their repos.

# yum install munin httpd

Configuring Munin server in Linux

Below are the steps we have to do in order to bring server up.

1) Add host details which need monitoring in /etc/munin/munin.conf

2) Configure apache web server to include munin details.

3) Create Username and password for web interface

4) Restart apache server

Step 1: Add hosts entry in this file in /etc/munin/munin.conf. Go to end of the file and a client to monitor. Here in this example, I added my DB server and its IP address to monitor

Example:

address 192.168.1.25
use_node_name yes

Save the file and exit.

Step 2: Edit/create munin.conf file in /etc/apache2/conf.d folder to include Munin Apache related configs. In another note, by default other Munin web related configs are kept in /var/www/munin folder.

# vim /etc/apache2/conf.d/munin.conf

Content:

Alias /munin /var/www/munin
<Directory /var/www/munin>
Order allow,deny
Allow from localhost 127.0.0.0/8 ::1
AllowOverride None
Options ExecCGI FollowSymlinks
AddHandler cgi-script .cgi
DirectoryIndex index.cgi
AuthUserFile /etc/munin/munin.passwd
AuthType basic
AuthName “Munin stats”
require valid-user
<IfModule mod_expires.c>
ExpiresActive On
ExpiresDefault M310
</IfModule>
</Directory>

Save the file and exit

Step 3: Now create a username and password for viewing muning graphs:

# htpasswd -c /etc/munin/munin-htpasswd munin

Note: For Redhat/Centos machines replace “apache2” with “httpd” in each path to access your config files.

Step 4: Restart Apache server so that Munin configurations are picked-up by Apache.

Ubuntu/Debian based:

# service apache2 restart

CentOS/Redhat based:

# service httpd restart

CentOS7/Redhat7 based:

# systemctl restart httpd

Install and configure Munin client in Linux

Step 1: Install Munin client in Linux

# apt-get install munin-node

# yum install munin-node

Note: If you want to monitor your Munin server, then you have to install munin-node on that as well.

Step 2: Configure client by editing munin-node.conf file.

vim /etc/munin/munin-node.conf

Example:

allow ^127\.0\.0\.1$
allow ^10\.10\.20\.20$
# Which address to bind to;
host *
# And which port
port 4949

Note: 10.10.20.20 is my Munin server and it connections to 4949 port on client to get its data.

Step 3: Restart munin-node on client

# service munin-node restart

# service munin-node restart

# systemctl restart munin-node

Testing connection

check if you are able to connect client from server on 4949 port, other wise you have to open that port on client machine.

telnet db.linuxnix.com 4949

Accessing Munin web interface

http://munin.linuxnix.com/munin/index.html

Hope this helps to configure basic Munin server.

Sponsored Link

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).

Preparing Your system

Install apache web server using the following command

sudo apt-get install apache2

Now proceed with munin server installation 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.

Related posts

How does it work?

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 an 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).

Plugins

Plugins are small, standalone executables. They are easy to write, and can be written in any language. You can find many user contributed plugins in ​the contrib repository or easily write your own ones.