anchor.diff:      start_time = undefined,
       stop_time = undefined,
       previous_counter_values = [],
  +    last_rps_calculation_time = undefined,
       asserts = [],
       active = true :: true | false
   }).
  
positive.code:     {ok, GraphiteReporterRef} = init_exometer(Host, Port, ApiKey, MetricsPrefix, Metrics),
      erlang:send_after(?INTERVAL, self(), trigger),
      _ = [ok = mz_histogram:create(Nodes, Name) || {Name, histogram} <- lists:flatten(Metrics)],
      _ = random:seed(os:timestamp()),
      {ok, #s{
          prefix = MetricsPrefix,
          nodes = Nodes,
          supervisor_pid = SuperPid,
          graphite_reporter_ref = GraphiteReporterRef,
          last_tick_time = os:timestamp(),
          start_time = os:timestamp(),
          previous_counter_values = [],
          asserts = Asserts,
          active = true
          }}.
  
negative.code:         _ -> {error, not_found}
      end.
  
  eval_rps(#s{previous_counter_values = PreviousData, last_rps_calculation_time = LastRPSCalculationTime} = State, Now) ->
      TimeInterval = timer:now_diff(Now, LastRPSCalculationTime),
      case TimeInterval > 1000000 of
          false -> State;
          true ->
              Counters = [N || {[_, N], counter, _} <- exometer:find_entries([?GLOBALPREFIX])],
              NewData = lists:foldl(
                  fun (Metric, Acc) ->
                      NewMetric = Metric ++ ".rps",
                      Old = proplists:get_value(NewMetric, Acc, 0),
                      {ok, [{value, New}]} = exometer:get_value([?GLOBALPREFIX, Metric], value),
                      HitsPerSecond = ((New - Old) * 1000000) / TimeInterval,
                      ok = exometer:update_or_create([?GLOBALPREFIX, NewMetric], HitsPerSecond, gauge, []),
                      lists:keystore(NewMetric, 1, Acc, {NewMetric, New})
                  end, PreviousData, Counters),
              State#s{previous_counter_values = NewData, last_rps_calculation_time = Now}
      end.
  
  aggregate_metrics_data(Metrics) ->
      lists:foldl(
  