[TC-357] Edge Server Parent Configuration Validation

[limited]

We recently had an issue where several edge servers received configs which did not indicate a mid tier parent cache. These configs caused the edge caches to try to reach the origins directly which caused 502 responses for several customers since their origins are locked down.

I am proposing a edge server config validation for this type of misconfiguration that would either prevent it or at least alert the person submitting the config that there may be a problem.

Author: Ryan Durfey
JIRA Link: https://issues.apache.org/jira/browse/TC-357

[mitchell852]

@ryandurfey - can you provide a bit more information around this? for example, what type of delivery service was this if you remember?