---
features:
  - |
    The nova-manage discover_hosts command now has a ``--by-service`` option which
    allows discovering hosts in a cell purely by the presence of a nova-compute
    binary. At this point, there is no need to use this unless you're using ironic,
    as it is less efficient. However, if you are using ironic, this allows discovery
    and mapping of hosts even when no ironic nodes are present.