anchor.diff:  
   -record(state, {
       last_rx_bytes :: integer() | not_available,
  -    last_tx_bytes :: integer() | not_available
  +    last_tx_bytes :: integer() | not_available,
  +    last_trigger_timestamp :: erlang:timestamp() | not_available
       }).
   
   interval() -> 10000. % ten seconds
  
positive.code: metric_names(Nodes) ->
      [
         [{metric_name(T, N), gauge} || N <- Nodes]
         || T <- ["la1", "cpu", "ram", "nettx", "netrx"]
      ].
  
  %% gen_server callbacks
  
negative.code:     {noreply, State}.
  
  handle_info(trigger,
      #state{last_rx_bytes = LastRXBytes,
          last_tx_bytes = LastTXBytes,
          last_trigger_timestamp = LastTriggerTimestamp} = State) ->
  
      Now = os:timestamp(),
  
      LastIntervalDuration = case LastTriggerTimestamp of
          not_available -> interval();
          _ -> timer:now_diff(Now, LastTriggerTimestamp)
      end,
      ok = mzb_metrics:notify({metric_name("interval"), gauge}, LastIntervalDuration / 1000),
  
      case cpu_sup:avg1() of
          {error, LAFailedReason} ->
  