The REST API docs for ArcGIS do mention that a healthcheck URL exists at http://<host>/<instance>/rest/info/healthCheck - however I'm having an issue trying to determine what the healthCheck URL would be for the production instance that ArcGIS is hosting for us. I would think it would be something like:
https://utility.arcgis.com/usrsvcs/rest/info/healthcheck
However it doesn't appear that this works. Is there a healthcheck URL for the managed REST API?