---
upgrade:
  - |
    The following deprecated scheduler filters have been removed.

    RetryFilter
      Deprecated in Train (20.0.0). The RetryFilter has
      not been required since Queens following the completion of the
      return-alternate-hosts blueprint

    Aggregatefilter, AggregateRAMFilter, AggregateDiskFilter
      Deprecated in Train (20.0.0). These filters have not worked
      correctly since the introduction of placement in ocata.

    On upgrade operators should ensure they have not configured
    any of the new removed filters and instead should use placement
    to control cpu, ram and disk allocation ratios.

    Refer to the `config reference documentation`__ for more information.

    .. __: https://docs.openstack.org/nova/latest/admin/configuration/schedulers.html#allocation-ratios
