[Wolves] Nagios Talk - Q&A Follow-Up Information

[James Turner]

The following points were not adequately addressed during tonight's talk:


1. Host and service dependencies

See the following page from the manual on what they are for and how to set 
them up:

http://nagios.sourceforge.net/docs/2_0/dependencies.html

Similar to how specifying the network topology prevents unnecessary duplicate 
notifications being sent out when a router outage occurs, service and host 
dependencies prevent unnecessary notifications being sent out when hosts or 
services that depend on each other fail. This dependency can be independent 
of the physical network topology.

For example, the following two events might each cause a single notification 
to be triggered, informing different support staff as appropriate:

 - The SpodProject Wiki just crashed due to an application-specific error
 - The back-end database server that several web sites (including SpodProject
   Wiki) depend on just crashed, affecting them all

The second scenario might not involve notification or corrective action from 
staff responsible for maintaining SpodProject Wiki but not responsible for 
the underlying database server itself.

(Hope that makes sense!)


2. Installing a non-obsolete Nagios version under Ubuntu:

The following page describes how to install the current version of Nagios 
(2.6) from source on Ubuntu Edgy:

http://www.ubuntuforums.org/showthread.php?t=223498

Aside: Notice preinstall step 2 - libgd2-dev - the equivalent to this got 
forgotten by the Fedora Extras package maintainers, so none of the components 
that create graphs/charts work in their supplied RPM! Until they fix this, 
the easiest workaround is probably just to rebuild the package on a machine 
with the correct libraries installed.


Slides to be published on the 'Net shortly.

Happy networking,

James