Monitoring based on service not "checking-in" within last 3 minutes?
I have a background task that needs to watch for events and send customers email when an event occurs. For reliability, I can run the same task on 3 different servers independent of each other - but at any given time, only one should send out email alerts. What I need is that if the "current primary server" goes down, then another one should take over the "primary" responsibility. This is not a website. I could have these tasks "checkin" somewhere say every 2 minutes - and if they fail to check in, someone else becomes primary. And receiving such alert would be great.
Are there any tools, sites (preferably free in the LET spirit) that allow doing this? (BTW I am using mandrill for emails)