---
features:
  - |
    The scheduler can now use placement to more efficiently query for hosts within
    an availability zone. This requires that a host aggregate is created in nova
    with the ``availability_zone`` key set, and the same aggregate is created in
    placement with an identical UUID. The
    ``[scheduler]/query_placement_for_availability_zone`` config option enables
    this behavior and, if enabled, eliminates the need for the
    ``AvailabilityZoneFilter`` to be enabled.