anchor.diff:      case Ret of
           ok -> void;
           {error, _} ->
  -            %% @TODO >> enqueue
  +            %% @TODO enqueue a message (fail distribution of launch-info to a target-node)
               ok
       end,
       rebalance_3(Rest, RebalanceProcInfo);
  
positive.code:     case rpc:call(Node, ?API_STORAGE, rebalance, [Info], ?DEF_TIMEOUT) of
          ok ->
              rebalance_5(T, Acc);
          {_, Cause}->
              ?error("rebalance_5/2", "node:~w, cause:~p", [Node, Cause]),
              rebalance_5(T, [{Node, Cause}|Acc]);
          timeout = Cause ->
              ?error("rebalance_5/2", "node:~w, cause:~p", [Node, Cause]),
              rebalance_5(T, [{Node, Cause}|Acc])
      end.
  
  
  
negative.code: %% @doc Do Rebalance which affect all storage-nodes in operation.
  %% [process flow]
  %%     1. Judge that "is exist attach-node OR detach-node" ?
  %%     2. Distribute every storage node from manager
  %%     3. Confirm callback.
  %%
  -spec(rebalance() ->
               ok | {error, any()}).
  