"Munin" means "memory".
Munin the tool surveys all your computers and remembers what it saw. It presents all the information in 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, and quite possibly applications as well. 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 all limited resources.
It uses the excellent RRDTool and is written in Perl. Munin has a master/node architecture in which the master connects to all the nodes at regular intervals and asks them for sdata. 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).
Download Munin
http://sourceforge.net/project
Munin Documentation
http://munin.projects.linpro
Munin Plugins
http://munin.projects.linpro
Munin in Debian
Munin is in the Debian archive in two parts
- munin((munin server) - the part that creates the monitoring graphs
- munin-node((munin Client) - the munin client program.
If you want to install munin server you need to install munin and munin-node packages using the following command
#apt-get install munin munin-node
this will install munin in /etc/munin directory this includes the following files
munin.conf munin-node.conf plugin-conf.d plugins templates
This will install files for webserver root directory in /var/www/munin directory this includes the following files
definitions.html index.html localdomain logo.png style.css
If you want to configure munin server you need to edit the /etc/munin/munin.conf file.The sample file looks like this
# Example configuration file for Munin, generated by 'make build'
# The next three variables specifies where the location of the RRD
# databases, the HTML output, and the logs, severally. They all
# must be writable by the user running munin-cron.
dbdir /var/lib/munin
htmldir /var/www/munin
logdir /var/log/munin
rundir /var/run/munin
# Where to look for the HTML templates
tmpldir /etc/munin/templates
# Make graphs show values per minute instead of per second
#graph_period minute
# Drop somejuser@fnord.comm and anotheruser@blibb.comm an email everytime
# something changes (OK -> WARNING, CRITICAL -> OK, etc)
#contact.someuser.command mail -s "Munin notification" somejuser@fnord.comm
#contact.anotheruser.command mail -s "Munin notification" anotheruser@blibb.comm
#
# For those with Nagios, the following might come in handy. In addition,
# the services must be defined in the Nagios server as well.
#contact.nagios.command /usr/sbin/send_nsca -H nagios.host.com -c /etc/send_nsca.cfg
# a simple host tree
[localhost.localdomain]
address 127.0.0.1
use_node_name yes
In this above sample config file we need to look maily these files
dbdir /var/lib/munin
htmldir /var/www/munin
logdir /var/log/munin
rundir /var/run/munin
If you want to change any of the paths you need to menction here
Most Important thing is adding clients machines to munin.conf file for this you can see by default localhost.localdomain is added under a simple host tree that looks like this
# a simple host tree
[localhost.localdomain]
address 127.0.0.1
use_node_name yes
Now server side configuration ready. Now we are going check clients configuration
Munin Clients Configuration in Debian
If you want to monitor any number of client machines using munin you need to install munin-node package in all your clients machines
Installing munin Client in Debian
If you want to install munin client in your machine you need to enter the following command
#apt-get install munin-node
This is install munin node package and it will create a folder called /etc/munin this contains the following files
munin-node.conf plugin-conf.d plugins
munin-node.conf - Client Configuration File
plugin-conf.d - Configuration of plugins for this node
plugins - A directory in which each file is a symlink to a real plugin in /usr/share/munin/plugins
Now you need to configure the munin-node.conf file
same file looks like this
#
# Example config-file for munin-node
#
log_level 4
log_file /var/log/munin/munin-node.log
port 4949
pid_file /var/run/munin/munin-node.pid
background 1
setseid 1
# Which port to bind to;
host *
user root
group root
setsid yes
# Regexps for files to ignore
ignore_file ~$
ignore_file \.bak$
ignore_file %$
ignore_file \.dpkg-(tmp|new|old|dist)$
ignore_file \.rpm(save|new)$
# Set this if the client doesn't report the correct hostname when
# telnetting to localhost, port 4949
#
#host_name localhost.localdomain
host_name munintest.test.com
# A list of addresses that are allowed to connect. This must be a
# regular expression, due to brain damage in Net::Server, which
# doesn't understand CIDR-style network notation. You may repeat
# the allow line as many times as you'd like
allow ^127\.0\.0\.1$
allow ^172\.30\.5\.132$
In the above configuration file there are two important things you need to enter first one is under
#host_name localhost.localdomain you need to add your client machine fully qualified name
#host_name localhost.localdomain
host_name munintest.test.com
Second one is you need to enter the server ipaddress by defauly you can see 127.0.0.1 in your config file under that you need to add your munin server ipaddress example as follows
allow ^127\.0\.0\.1$
allow ^172\.30\.5\.132$
Now you need to add plugins for for your client machine to monitor the required services for this edit the file located at /etc/munin/plugin-conf.d/munin-node sample file looks like below
# This file is used to configure how the plugins are invoked.
#
# user <user> # Set the user to run the plugin as.
# group <group> # Set the group to run the plugin as.
# command <command> # Run <command> instead of the plugin. %c expands to
# what would normally be run.
# env.<variable> # Sets <variable> in the plugin's environment, see the
# individual plugins to find out which variables they
# care about.
[apt]
user root
[cps*]
user root
[fw_conntrack]
user root
[hddtemp_smartctl]
user root
[if_*]
user root
[if_err_*]
user nobody
here you need to add the user,group,command,env.
Now look in to plugins/ directory
A directory in which each file is a symlink to a real plugin in /usr/share/munin/plugins.
Any plugin linked in here will be checked for and displayed in the resulting web pages.
Add the plugins you want (e.g. if running exim4 then I'd add exim_mailqueue and exim_mailstats).
You'll need to set user/group rights in the munin-node conf file.
Most plugins can be run from the command line with the autoconf param to check if they can run - e.g.
./exim_mailstats autoconf yes
You can add any plugins you want to monitor and default plugins are located at /etc/munin/plugins directory
Default munin Plugins are as follows
cpu entropy forks if_eth0 iostat memory mysql_slowqueries open_files processes df exim_mailqueue if_err_eth0 if_eth1 irqstats mysql_bytes mysql_threads open_inodes swap df_inode exim_mailstats if_err_eth1 interrupts load mysql_queries netstat postfix_mailvolume vmstat
Now you need to restart your munis service for your client machine
#/etc/init.d/munin-node restart
That's it from client side configuration
Finall one important step you need to do in your munin server config file that is located in your munin server machine /etc/munin/munin.conf
You need to add all your client machines list under this
# a simple host tree
[localhost.localdomain]
address 127.0.0.1
use_node_name yes
example:-
# a simple host tree
[localhost.localdomain]
address 127.0.0.1
use_node_name yes
[munintest.test.com] - This is our test client we have mentioned earlier
address 172.30.5.129
use_node_name yes
After entering all the client machine details you need to the following command to take the effect of our new changes effect.
#/usr/share/munin/munin-update --force-root
Running munin and testing munin in Debian
Munin sets up a cron job via the file /etc/cron.d/munin which will run /usr/bin/munin-cron.
Running this file will poll each of the nodes - and then will create the graphs in /var/www/html which you can then browse under http://ipaddress/munin
Examples can be found here: http://www.linpro.no/projects
Keeping an eye on these graphs will help you to keep your servers running healthily - and can give advance warning of problems to come.
If you have any problems you need to check the log files of munin located at /var/log/munin directory
On server side Important log files are
munin-node.log - should show the connections that are occuring.
munin-graph.log - should show info on the services being graphed.
munin-html.log - should show info on the html being generated.
On Client side important log files are
munin-node.log - should show the connections that are occuring
No comments:
Post a Comment