Don't fail to take advantage of the open source networking tool Nagios' extensive documentation, says Taylor Dondich, author of Network Monitoring with Nagios (O'Reilly). One changed parameter can leave you with unwanted results for you network monitoring platform.
Find out where to go for customized plug-ins that will help you monitor Windows and Linux machines and get some timesaving tips.
What sets Nagios apart from other open source network monitoring tools like Big Brother, OpenNMS, OpenView and SysMon?
Taylor Dondich: Nagios has been around for quite a while. Before it was called Nagios, it was named NetSaint. For many years, it's been building up a very strong community. When I evaluate a product, especially open source, I really look at the community first.
If the community is strong, it means that I've got an abundance of help out there. And with a tool that is as flexible as Nagios, the community helps extend Nagios by building plug-ins and add-ons for it. This makes Nagios even more promising to me as a user.
What are some Nagios plug-ins that users would find helpful?
Dondich: I think the standard Nagios plug-in library is pretty extensive. They've got you covered from checking basic network services all the way to checking the status of your game servers. They also have check_tcp and check_udp, which are generic enough to check any devices that speak TCP or UDP. So, if you have a device that isn't covered by the standard library, it's pretty easy to create your own.
Because it's so easy to create new plug-ins, there's a myriad of available plug-ins made by users of Nagios. The best place to find them is on Nagios Exchange. They have a Check Plugin category that probably has a plug-in for the device you're trying to support. Groundwork just released a set of plug-ins that performs WMI monitoring without an agent. This is probably a big plus for anyone with Windows machines to monitor. These plug-ins are available on Nagios Exchange.
What are some tools that will increase and extend Nagios functionality?
Dondich: Again, I have to bring up Nagios Exchange as a good source. Because Nagios is fairly flexible and open, there are a great deal of tools to make your life easier when working with it. One of the most frustrating things about Nagios is configuring it. The best thing to do is get a good configuration tool. The most popular ones out in the community are Groundwork Monarch and Groundwork Fruit, which I wrote.
It may seem a bit strange that two Nagios configuration tools come out of the same company, but they both perform the same tasks in different fashions and they both have their pluses in that regard. Replacing the user interface (UI) of Nagios is a popular task and there are some unique extensions out there. An interesting one I saw was displaying device statuses overlaid across Google Earth. There are also extensions to send reports via email and to view Nagios data through a console screen instead of through a Web browser.
What are some shortcuts and gotchas that users should know when working with Nagios?
Dondich: There aren't shortcuts so much as timesavers. Nagios has extensive documentation so, by all means, read it first. I know when I first started using Nagios, I'd change a parameter somewhere in my constant configuration changes, and all of a sudden, my entire network-monitoring platform wasn't functioning the way I wanted. Use the documentation as a constant reference when modifying your configuration.
Also, implementing templates in your configuration is a huge time saver. A good template library can reduce the effort needed to add new devices to be monitored.
Lastly, Nagios has a very strong user community. If you run into a problem or have a question that the documentation doesn't answer, the Nagios mailing list is the place to go. Users are friendly and extremely informative. They'll help you out.