anchor.diff:  -define(METRIC_AUTH_SUCCESS, [iorio, auth, success]).
   -define(METRIC_LISTEN_ONCE, [iorio, listen, active, once]).
   -define(METRIC_LISTEN_ACTIVE, [iorio, listen, active, active]).
  +-define(METRIC_LISTEN_FALSE, [iorio, listen, active, not_active]).
   -define(METRIC_HTTP_ACTIVE_REQS, [iorio, api, http, active_requests]).
   -define(METRIC_HTTP_REQ_TIME, [iorio, api, http, req_time]).
   
  
positive.code: 
      exometer:new(?METRIC_LISTEN_ONCE, counter, []),
      exometer:new(?METRIC_LISTEN_ACTIVE, counter, []),
  
  
      exometer:new(?METRIC_CORE_PING, spiral, [{time_span, 60000}]),
      exometer:new(?METRIC_CORE_PUT, spiral, [{time_span, 60000}]),
  
negative.code: 
  http_stats() ->
      [{listen, [{active, unwrap_metric_value(?METRIC_LISTEN_ACTIVE)},
                 {not_active, unwrap_metric_value(?METRIC_LISTEN_FALSE)},
                 {once, unwrap_metric_value(?METRIC_LISTEN_ONCE)}]},
       {auth, [{error, unwrap_metric_value(?METRIC_AUTH_ERROR)},
               {success, unwrap_metric_value(?METRIC_AUTH_SUCCESS)}]},
  