anchor.diff:    <% frontend_hosts.count.times do |i| %>
     {
     .backend = smartanswers_<%= i %>;
  +  }
  +  <% end %>
  +}
  +director designprinciples round-robin {
  +  <% frontend_hosts.count.times do |i| %>
  +  {
  +  .backend = principles_<%= i %>;
     }
     <% end %>
   }
  
positive.code:     set req.backend = whitehall;
    } else if (req.url ~ "^/maternity(\.xml|\.json|\.ics)?(\?.*|)$|^/paternity(\.xml|\.json|\.ics)?(\?.*|)$") {
      set req.backend = planner;
    } else {
      set req.backend = frontend;
    }
  
negative.code:     .threshold = 3;
    }
  }
  
  backend designprinciples_<%= i %> {
    .host = "<%= host %>";
    .port = "8085";
    .host_header = "designprinciples.<%= govuk_platform %>.alphagov.co.uk";
    .probe = {
      .url = "/";
      .interval = 5s;
      .timeout = 1s;
      .window = 5;
      .threshold = 3;
    }
  }
  
  <% end %>
  
  director frontend round-robin {
  