We use this approach for these types of problems. First, the task has to write a timestamp to a file in S3 or EFS. This file is the external evidence that the task ran to completion. Then you need an http based service that will read that file and calculate if the time stamp is valid ie has been updated in the last hour. This could be a simple php or nodejs script. This process is exposed to the public web eg https://example.com/heartbeat.php. This script returns a http response code of 200 if the timestamp file is present and valid, or a 500 if not. Then we use StatusCake to monitor the url, and notify us via its Pager Duty integration if there is an incident. We usually include a message in the response so a human can see the nature of the error.
This may seem tedious, but it is foolproof. Any failure anywhere along the line will be immediately notified. StatusCake has a great free service level. This approach can be used to monitor any critical task in same way. We've learned the hard way that critical cron type tasks and processes can fail for any number of reasons, and you want to know before it becomes customer critical. 24x7x365 monitoring of these types of tasks is necessary, and helps us sleep better at night.
Note: We always have a daily system test event that triggers a Pager Duty notification at 9am each day. For the truly paranoid, this assures that pager duty itself has not failed in some way eg misconfiguratiion etc. Our support team knows if they don't get a test alert each day, there is a problem in the notification system itself. The tech on duty has to awknowlege the incident as per SOP. If they do not awknowlege, then it escalates to the next tier, and we know we have to have a talk about response times. It keeps people on their toes. This is the final piece to insure you have robust monitoring infrastructure.
