anchor.diff:      master_pid = Pid,
       keys_in_flush = KIF,
       keys_to_expire = ToExpire,
  -    flush_times = FT
  +    flush_countdown_timers = FT
   }) ->
       NewKeys = maps:merge(NotFlushed, CachedKeys),
   
  -    Timestamp = os:timestamp(), % @TODO VFS-7014 switch to unified time API
  +    FlushTimer = countdown_timer:start_seconds(?FLUSH_COOLDOWN),
       {KIF2, FT2, Flushed} = case application:get_env(?CLUSTER_WORKER_APP_NAME, tp_fast_flush, on) of
           on ->
               Filtered = maps:filter(fun(_K, {V, _}) ->
  
positive.code:     keys_in_flush = KiF,
      cached_keys_to_flush = CachedKeys,
      keys_to_inactivate = ToInactivate,
      flush_times = FT
  }) ->
      {NewCachedKeys, NewKiF, NewFT, State2} =
          case application:get_env(?CLUSTER_WORKER_APP_NAME, tp_fast_flush, on) of
              on ->
                  KiFKeys = maps:keys(KiF),
                  ToFlush0 = maps:without(KiFKeys, CachedKeys),
                  CooldownUS = timer:seconds(?FLUSH_COOLDOWN) * 1000,
  
                  Now = os:timestamp(), % @TODO VFS-7014 switch to unified time API
                  ToFlush = maps:filter(fun(K, _V) ->
                      FlushTime = maps:get(K, FT, {0,0,0}),
                      timer:now_diff(Now, FlushTime) > CooldownUS
                  end, ToFlush0),
  
                  case {maps:size(ToFlush), maps:size(ToFlush0)} of
  
negative.code:         _ -> CurrentRef
      end,
  
      StopWatch = stopwatch:start(),
      ToExpire2 = maps:fold(fun
          (K, {_, #{expiry := Expiry, disc_driver := undefined}}, Acc)
              when Expiry > 0 ->
              % Save expiry to compare with StopWatch in future
              maps:put(K, {StopWatch, Expiry}, Acc);
          (_, _, Acc) ->
              Acc
      end, ToExpire, Flushed),
  