---
upgrade:
  - |
    The online data migration ``migrate_instances_add_request_spec``, which was
    added in the 14.0.0 Newton release, has now been removed. Compatibility
    code in the controller services for old instances without a matching
    ``request_specs`` entry in the ``nova_api`` database is also gone.
    Ensure that the ``Request Spec Migration`` check in the
    ``nova-status upgrade check`` command is successful before upgrading to
    the 19.0.0 Stein release.