bramgn··on Ask HN: How do you get notifications if something doesn't happen?Then i think the solution you came up with is pretty good for your situation. If this external service is stable, of course.
bramgn··on Ask HN: How do you get notifications if something doesn't happen?If this is a Unix-like environment, have you thought about running a cron job that runs your script and decides to send a message based on the results?