anchor.diff:      %% Technically, we could still write data that falls within a range that is
       %% to be deleted by the vacuum.  See the `timestamp()' function doc.
       case valid_ts(Time + Len, Bucket, State) of
  -        {false, State1} ->
  +        {false, Exp, State1} ->
  +            lager:warning("[~p:~p] Trying to write beyond TTL: ~p -> ~p < ~p",
  +                          [Bucket, Time, Len, Exp]),
               State1;
  -        {true, State1} ->
  +        {true, _, State1} ->
               %% Elemements of the cacgh have the following logic:
               %% 1: Bucket + Metric
               %% 2: The start time (index in the file)
  
positive.code:         %% past if writing batches but this is a problem for another day!
          {Exp, State1} when is_integer(Exp),
                             TS < Exp ->
              {false, State1};
          {_, State1} ->
              {true, State1}
      end.
  
  %% Return the latest point we'd ever want to save. This is more strict
  
negative.code:   when is_binary(Bucket), is_binary(Metric), is_integer(Time) ->
      Count = mmath_bin:length(Value),
      case valid_ts(Time + Count, Bucket, State) of
          {true, _, State1} ->
              State2 = repair_update_cache(Bucket, Metric, Time, Count, Value,
                                           State1),
              {noreply, State2};
          {false, _, State1} ->
              {noreply, State1}
      end;
  
  