Error returned in HEAT when running reports - "Unhandled system exception: The request failed with HTTP status 503: Service Unavailable"

Version 1

    Details

    Reports were previously working in HEAT but now throw this error:  "Unhandled system exception: The request failed with HTTP status 503: Service Unavailable"


    Resolution

    Isolated that the root cause was not directly associated to any HEAT Service Management services and that in fact if you launch the "Reporting Services Configuration Manager" and test the Web Service URL a HTTP 503 is also returned.


    Suggested using SSRS HTTP.SYS Logging to assist with identifying root cause of service un-availability.  See following TechNet link: