Something definitely seems off here, from the fact that RDS chose to scale to the response you got from support (who've always been... mostly ok in my experience).
First of all I think I'd like to find out a little more context before I jump to any conclusions;
- Does Cloudwatch confirm that RDS "needed" to scale? And if it does, do any other metrics increase simultaneously with an increase in the storage being used?
- Other than the (presumably) one change made to that RDS instance at ~4.30AM, were there any other changes made to it, specifically to its storage, prior to the autoscaling event?
- Had this service been tested on RDS prior to the migration being performed?
- Were any other changes made, that may potentially effect your DB? For example a query being changed or something of that nature.
To me, it sounds like support found something that suggested whatever was happening to RDS at the time was "someone else's problem" under their shared responsibility model. Whether or not that's true - who knows but from how you've described it they definitely seem to be trying to palm you off, worth mentioning to your TAM/rep if you have one because this is pretty poor service.
First of all I think I'd like to find out a little more context before I jump to any conclusions;
- Does Cloudwatch confirm that RDS "needed" to scale? And if it does, do any other metrics increase simultaneously with an increase in the storage being used?
- Other than the (presumably) one change made to that RDS instance at ~4.30AM, were there any other changes made to it, specifically to its storage, prior to the autoscaling event?
- Had this service been tested on RDS prior to the migration being performed?
- Were any other changes made, that may potentially effect your DB? For example a query being changed or something of that nature.
To me, it sounds like support found something that suggested whatever was happening to RDS at the time was "someone else's problem" under their shared responsibility model. Whether or not that's true - who knows but from how you've described it they definitely seem to be trying to palm you off, worth mentioning to your TAM/rep if you have one because this is pretty poor service.