startUp = function() {
      appUtil.optComponents(self.loaded, Constants.RESERVED.START, function(err) {
        self.state = STATE_START;
        if(err) {
          utils.invokeCallback(cb, err);
        } else {
          logger.info('%j enter after start...', self.getServerId());
          self.afterStart(cb);
        }
      });
    }
Start application. It would load the default components and start all the loaded components.

@param  {Function} cb callback function
@memberOf Application