anchor.diff:                                  monitor_dict = MonDict} = State,
       case dict:size(WaitingPool) of
           0 ->
  -            ?xdcr_debug("nothing to schedule, # of active reps: ~p, # of acrtive target nodes: ~p",
  -                        [dict:size(ActivePool), dict:size(TargetLoad)]),
  +            ?log_debug("nothing to schedule, # of active reps: ~p, # of acrtive target nodes: ~p",
  +                       [dict:size(ActivePool), dict:size(TargetLoad)]),
               State;
           _ ->
               {WaitingPid, Signal, TargetNode} = choose_pid_to_schedule(WaitingPool,
  
positive.code:     gen_server:call(Server, {change_tokens, NewTokens}, infinity).
  
  init({Count, Type, Parent}) ->
      ?xdcr_debug("init concurrent throttle process, pid: ~p, type: ~p"
                  "# of available token: ~p", [self(), Type, Count]),
      WaitingPool = dict:new(),
      ActivePool = dict:new(),
      TargetLoad = dict:new(),
  
negative.code:     %% signal vb replicator
      Pid ! Signal,
  
      ?log_debug("grant one token to rep (pid: ~p, targetnode: ~p), available tokens: ~p (total tokens: ~p)",
                 [Pid, TargetNode, NewCount, TotalTokens]),
  
      NewState = State#concurrency_throttle_state{
                   avail_tokens = NewCount,
  