anchor.diff:  
   -spec init([integer()]) -> {'ok', state()}.
   init([]) ->
  -    Interval = application:get_env(vmq_server, interval, 10),
  +    Interval = vmq_config:get_env(sys_interval, 10),
       ets:new(?TABLE, [public, named_table, {write_concurrency, true}]),
       init_table(items()),
  -    IntervalMS = Interval * 1000,
  -    TRef = erlang:send_after(IntervalMS, self(), publish),
  +    {IntervalMS, TRef} =
  +        case Interval of
  +            0 -> {undefined, undefined};
  +            _ -> 
  +                T = Interval * 1000,
  +                {T, erlang:send_after(T, self(), publish)}
  +    end,
       erlang:send_after(1000, self(), shift),
       {ok, #state{interval=IntervalMS, ref=TRef}}.
   
  
positive.code: %% Copyright 2014 Erlio GmbH Basel Switzerland (http://erl.io)
  %%
  %% Licensed under the Apache License, Version 2.0 (the "License");
  %% you may not use this file except in compliance with the License.
  
negative.code:     shift(Now, Rest).
  
  update_item(Key, UpdateOp) ->
      try
          ets:update_counter(?TABLE, Key, UpdateOp)
      catch error:badarg -> error
      end.
  
  averages([], Acc) -> Acc;
  averages([{Key, counter}|Rest], Acc) ->
  