anchor.diff:      keys_in_flush = KiF,
       cached_keys_to_flush = CachedKeys,
       keys_to_inactivate = ToInactivate,
  -    flush_times = FT
  +    flush_countdown_timers = 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
  +                    case maps:get(K, FT, undefined) of
  +                        undefined -> true;
  +                        TimerInstance -> countdown_timer:is_expired(TimerInstance)
  +                    end
                   end, ToFlush0),
   
                   case {maps:size(ToFlush), maps:size(ToFlush0)} of
  
positive.code:     datastore_links_iter:token()) -> {datastore_links_iter:token(), cached_token_map()}.
  set_link_token(Tokens, #link_token{restart_token = Token} = FullToken,
      #link_token{restart_token = {cached_token, Token2}}) ->
      {FullToken#link_token{restart_token = {cached_token, Token2}},
          maps:put(Token2, {Token, os:timestamp()}, Tokens)}; % @TODO VFS-7014 switch to unified time API
  set_link_token(Tokens, Token, #link_token{} = OldToken) ->
      Token2 = erlang:make_ref(),
      set_link_token(Tokens, Token,
  
negative.code:                         Futures = datastore_disc_writer:flush_async(ToFlush2),
                          gen_server:cast(Pid, {wait_flush, Ref, Futures}),
  
                          Timer = countdown_timer:start_seconds(?FLUSH_COOLDOWN),
                          FT2 = maps:fold(fun(K, _V, Acc) ->
                              maps:put(K, Timer, Acc)
                          end, FT, ToFlush2),
  
                          {Waiting, KiF2, FT2, State}
  