Does anyone know of an open source/freeware linux service monitoring application? I want to be able to monitor pop3, imap, http, mysql etc from some form of an application that can alert me if downtime occurs....
Hey oc3. The install is actually pretty simple. Just follow the install. It is the configuration files that is where you will spend your time. The examples are quite good though. I also recommend that you join the mailing list if you decide to use it.
I have to agree that the only tricky part is getting the config files setup. If you monitor a lot of servers/services, take some time and work on getting some good templates setup. It will save you a lot of time in the long run.
It should run on a separate box. This allows you to see if the box is remotely reachable. This is important to be able to detect if the server is down due to a routing issue, server failure, etc and to be able to email/page you in the event of a failure. There is an extension that you can run on the monitored box called nrpe that allows you to extract more specific information such as server load, number of process, etc from the server.