How to get notified about Ruby (Rack) errors in Rails 3

On a Rails 3.2 production site I have ExceptionNotifier installed, which sends me mails when something goes wrong. But I have noticed that when the site genererates a "Ruby (Rack) application could not be started" error, I do not get notified. How/what do I configure in order to get notified by mail when this error occurs? Thanks

As the message implies the app couldn’t be started, so the app isn’t in a position to tell you about the fact that it encountered an error.

You’ll need to use something external to the app. That could be something on your server (monit, nagios etc.) or something external that monitors your site’s availability (such as pingdom)

If the failure can be logged to rsyslog (I think passenger might be able to do this if it can’t start your app) then I believe rsyslog can be configured to email you.


Hi Fred,

thanks for the suggestions. I will look into each of them and hopefully when of them will suite my needs. Thanks.