We have previously agreed that scheduler hints in Nova are an open ended thing. It's expected for sites to have additional scheduler filters which expose new hints. The way we handle that with our strict jsonschema is that we allow additional properties - https://github.com/openstack/nova/blob/1734ce7101982dd95f8fab1ab4815bd258a33744/nova/api/openstack/compute/schemas/scheduler_hints.py#L65 This means that if you specify some garbage hint, you don't get feedback that it was garbage in your environment. That lost a couple of days building multinode tests in the gate. Having gotten used to the hints that "you've given us bad stuff", this was a stark change back to the old world. Would it be possible to make it so that the schema could be explicitly extended (instead of implicitly extended). So that additional properties=False, but a mechanism for a scheduler filter to register it's jsonschema in? -Sean -- Sean Dague http://dague.net