One of the claims that I've made about the Ethereum Alarm Clock is that it should be capable of being extremely reliable. Today, I am proud to introduce everyone to the Reliability Canary an attempt at measuring the reliability of the Alarm service.
The canary is a contract that continually reschedules a call to itself approximately every 2 hours. Each time this happens a counter is incremented. If the scheduled call is not executed, the canary dies.
Source code available here
I'm still experimenting a bit with how I want this contract to work. Once I'm happy with it and it's been running fine for a few days with no problems I'll plan on funding the contract with enough ether to last for a few weeks.
I'm hoping that I don't have to kill too many canaries.
Our first canary has been euthanized in favor of a newer more healthy canary which was just deployed. The new canary contract takes less gas per heartbeat and fixed a bug related to how it sets it's initial timestamp.