Nagios Monitoring
Nagios is an open source computer system monitoring, network monitoring and infrastructure monitoring softtware application.
Nagios, originally created under the name NetSaint, was written and is currently maintained by Ethan Galstad along with a group of developers who are actively maintaining both the official and unofficial plugins.
Official site: http://www.nagios.org
This page summarizes my experience in monitoring servers, network devices and applications with Nagios.
Monitoring Hosts and Applications
Software
Nagios Core
The Nagios engine and web interface.
NRPE - Nagios Remote Plugin Executor
NRPE allows you to remotely execute Nagios plugins on other Linux/Unix machines.
This allows you to monitor remote machine metrics (disk usage, CPU load, etc.).
NRPE can also communicate with some of the Windows agent addons, so you can execute scripts and check metrics on remote Windows machines as well.
NSCA - Nagios Service Check Acceptor
NSCA is a Linux/Unix daemon allows you to integrate passive alerts and checks from remote machines and applications with Nagios.
Useful for processing security alerts, as well as redundant and distributed Nagios setups.
NSClient++ - Secure monitoring daemon
NSClient++ (nscp) aims to be a simple yet powerful and secure monitoring daemon.
It was built for Nagios/Icinga, but nothing in the daemon is Nagios/Icinga specific and it can be used in many other scenarios where you want to receive/distribute check metrics.
The deamon has 3 main functions:
Allow a remote machine (monitoring server) to request commands to be run on this machine (the monitored machine) which return the status of the machine.
Submit the same results to a remote (monitoring server).
Take action and perform tasks.
NSClient++ is designed to be open ended and allow you to customize it in any way you design thus extensibility is a core feature.
NSClient++ supports several protocols, including NRPE and NSCA.
Nagios Plugins
https://www.nagios-plugins.org/
The Nagios Plugins Development Team maintains a bundle of more than fifty standard plugins for Nagios, Icinga, Shinken, Naemon, and other monitoring applications that use the straighforward plugin interface originally invented by the Nagios folks,
Each plugin is a stand-alone command line tool that provides a specific type of check. Typically, your monitoring software runs these plugins to determine the current status of hosts and services on your network.
Some of the provided plugins let you check local system metrics (such as load averages, processes, or disk space usage), others use various network protocols (such as ICMP, SNMP, or HTTP) to perform remote checks. This allows for monitoring a large number of common host and service types.
You can get the latest releases from the download page.
Nagios Exchange
The central place where you'll find all types of Nagios projects - plugins, addons, documentation, extensions, and more. This site is designed for the Nagios Community to share its Nagios creations.
Documentation
