Enterprise Network Computing: OpenNMS Vs. Nagios: A Comparative Study

OpenNMS is the first enterprise-grade network management platform to be developed under the open-source model. The goal is for OpenNMS to be a truly distributed, scalable platform for all aspects of the FCAPS network management model, and to make this platform available to both open source and commercial applications. Nagios is a popular open source computer system and network monitoring software application. It watches hosts and services, alerting users when things go wrong and inform them again when the network works better. I have been trying to do a comparison of what Nagios does compared to openNMS after my  brief association in a test environment with our corporate network department.

• OpenNMS targets at the enterprise-sized organization which needs a scalable network management solution. Nagios is better suited to monitor a limited amount of servers which you can set up manually.
• Nagios conducts very little data collection. Other software  will be required for a more extensive data collection system. OpenNMS includes it from the beginning.
• Nagios is written in C and OpenNMS in Java. It makes Nagios a lot faster on older hardware.
• openNMS  supports SNMP natively, as well as common service checks. Nagios has no direct SNMP support.
• In comparison with openNMS, Nagios is very hard to configure and its GUI is very complicated.
• OpenNMS is a new enterprise grade monitoring system. Nagios runs via the remote plugin model, using the NRPE daemon to run scripts on remote hosts and report back to base.
• The popular convention is that there is a security concern in Nagios. It allows you to write plugins in just about any language and run them on remote servers. On the other hand, OpenNMS employs a Real-Time Console that allows the openNMS daemon to communicate network status updates with the front-end servlet engine in near-real-time. Since all of the servlets are protected by a realm module, the openNMS daemon must authenticate to the servlets.
• The Host Detail and Service Detail screens of Nagios are simply so big that they refresh themselves before you can scroll  half way down the page. Comparatively, the visibility is much better in openNMS.