We want to use Nagios for monitoring a Rails app. The reason is we just don't have a Rails app; we have Java and .Net apps and we want to use Nagios for all different apps; to have a centralized monitoring system. I know there are some great monitoring tools such as New Relic,Monit,etc. out there but they didn't want to go with anything different than Nagios. I am looking for a Nagios plugin to check the latency(uptime,downtime, how long does it take a page to load,response time,etc.) of our Rails app and couldn't find a good Nagios plugin. Does anybody know of a good Nagios plugin for monitoring latency in a Rails App? Thank you very much in advance for your help.
Uptime, downtime, response_time is handled by almost every nagios plugin. The standard check_http plugin should work. Be sure to test a real page (for example, a dynamic page) for the response time. If you test a static page, it might not hit the database etc and your response times will be incorrect (too perfect). If you run rails on a non-standard port, you can override the port it checks on with -p: http://nagiosplugins.org/man/check_http
A long time ago, in a previous life, I used Nagios for up/down but used Cacti for trending.
Also, this should be moved to serverfault.