anchor.diff:      case {lists:sort(Servers), lists:sort(KeepNodes), EjectNodes,
             unbalanced(Histograms)} of
           {S, S, [], false} ->
  -            error_logger:info_msg(
  -              "ns_orchestrator not rebalancing because already_balanced~n~p~n",
  -              [{Servers, KeepNodes, EjectNodes, Histograms}]),
  +            ns_log:log(?MODULE, ?REBALANCE_NOT_STARTED,
  +              "Not rebalancing because the cluster is alread balanced~n"),
               {reply, already_balanced, State};
           _ ->
               {ok, Pid, Ref} =
  
positive.code: 
  -define(REBALANCE_SUCCESSFUL, 1).
  -define(REBALANCE_FAILED, 2).
  
  %% gen_server callbacks
  -export([init/1, handle_call/3, handle_cast/2,
  
negative.code:             {reply, ok, State#state{rebalancer={Pid, Ref}, progress=[]}}
      end;
  handle_call({start_rebalance, _, _}, _From, State) ->
      ns_log:log(?MODULE, ?REBALANCE_NOT_STARTED,
                 "Not rebalancing because rebalance is already in progress.~n"),
      {reply, in_progress, State};
  handle_call(stop_rebalance, _From, State = #state{rebalancer={Pid, _Ref}}) ->
      Pid ! stop,
  