Open Stack

> 
>     The need arises when you need a way to use both the zones to be used for
> scheduling when no specific zone is specified. The only way to do that is
> either have a AZ which is a superset of the two AZ or the other way could be
> if the default_scheduler_zone can take a list of zones instead of just 1.

If you don't configure a default_schedule_zone, and don't specify an availability_zone to the request  - then I thought that would make the AZ filter in effect ignore AZs for that request.  Isn't that want you need ?