Looking to mointor a few servers for a small client of mine. I have a little bit of experience with nagios it just seems a bit cumbersome for this application. looking to see if anyone has any other suggestions before i go down that path.
Nagios is great, I use it at work to monitor a few hundred services. Once you understand how the config files and the plugins work, its actually really simple to use/configure. I would suggest getting the latest version from the nagios web site, and not using the one that comes in packages with most linux OS's as the packages tend to be very old.
Are your servers windows? Linux/Unix? Mixture?
Do you have a dedicated server to run nagios on? Maybe a little VM?
What kind of alerting do you want to do? Just email? EMail-> Text so you can get text messages? (We use both of these at work)
Theres also "LibreNMS" which is an open source fork of Observium that includes some of the "pro" features. Theres a VM image of LibreNMS, and you can set it to update automatically.
I switched to it when the Observium CEO started acting like a dick and made it clear he doesn't care about you unless you are a Fortune 100 company. I obviously have a bias against him, so keep that in mind.
I've discovered an open source tool called NetXMS which I find brilliant.
The reason I chose it was because the backend database can sit on SQL server (which means I can query it from other applications and included data from it in my SSRS reports, which are in turn used for the screen on my wall which lists things like open helpdesk tickets etc