def _delete_redundancy_routers(self, context, router_db):
        """To be called in delete_router() BEFORE router has been
        deleted in DB. The router should have not interfaces.
        """
        e_context = context.elevated()
        for binding in router_db.redundancy_bindings:
            self.delete_router(e_context, binding.redundancy_router_id)
            LOG.debug("Deleted redundancy router %s",
                      binding.redundancy_router_id)
        if router_db.gw_port_id:
            # delete ha settings and extra port for gateway (VIP) port
            self._delete_ha_group(e_context, router_db.gw_port_id)