---
upgrade:
  - |
    The ``SECONDARY zone`` RPC calls were moved from the ``mdns`` service to ``worker``
    service. When upgrading multi-controller deployments we recommend that you
    restart the ``central`` and ``worker`` services first to move the
    ``SECONDARY zone`` calls to the ``worker``, and once both services has been
    upgraded go ahead and restart the ``mdns`` service.
