From Wiki Centreon

check_graph_* plugins configuration

• presentation

'check_graph_*' has been developed for Oreon software and are specific. They manages data storage in rrd files and display graphs of its data over Oreon without using a parser like PerfParse or ODS. Those plugins can't run without Oreon software as they use Oreon's parameters to make a mapping from a service id to the service itself.

To do that, following Perl modules are required in the current Nagios plugins dirrectory :
Oreon.conf : provides most used MIB OID list
Oreon.pm  : provides Perl modules to catch information stored in Oreon's database.

• options

Those plugins have common options :
-g : to store data in a rrd file (requested if you want to graph)
-D : specify the directory where storing rrd files
-f : for perfdata compatible format output
-S : specific option providing the Oreon's service id to the plugin.

The -S option makes those plugins very specific, and have also a specific configuration in Oreon. When you build a check_graph_* command, you must put the last argument behind the -S option. It looks strange first but Oreon automatically set this parameter when you make a Nagios configuration export.

exemple : command configuration in oreon :

check_graph_uptime
%USER1%/check_graph_uptime -H %HOSTADDRESS% -C %ARG1% -v %ARG2% -g -f -S %ARG3%

service parameters :

command :    check_graph_uptime
parameters : !public!1

Take care, you mustn't put a last '!' behind the last parameter

Then, after a Nagios configuration export via Oreon, we can see in Nagios services.cfg :

define service {
    host_name       (my_host)
    service_description (my_service_description)
    ...
    command_check       check_graph_uptime!public!1!10_2
}

Oreon has automatically added the service id parameter. The rrd file corresponding to this service graph will have 10_2.rrd name.

Here, we can see that it is very important to not put a last '!' after the parameters cause if we did it, we would have check_graph_uptime!public!1!!10_2 that would not be understand correctly by plugin.

• running

As plugin is called by Nagios, it does :
- service check
- store data in rrd file
- send Nagios the check result

• graphs

Oreon have a look in your rrd directory, load all rrd file names and use its database to get services corresponding to 'service id' (remember : 10_2.rrd -> (my_service_description), (my_host)). Then, Oreon uses rrdtool graph engine to display graphs.

• overview

Graphing services this way present following aventages :
- you don't need to install anything but Oreon (no perfparse database, no ODS demon...)
- graphs simply uses Nagios plugins
- graphing this way is easy !

But, you can only graph services available in plugins.