def system_register_worker # :nodoc
      self.class.with_global_lock do
        workers = self.class.system_registered_workers.push(self.id)
        self.class.store_global_property(WORKERS_KEY, workers.join(','))
      end
    end
def system_register_worker # :nodoc
      self.class.with_global_lock do
        workers = self.class.system_registered_workers.push(self.id)
        self.class.store_global_property(WORKERS_KEY, workers.join(','))
      end
    end
register a worked id globally (for this application)