def _add_service(self, name, addrinfo):
        if name not in self.services:
            self.services[name] = {}
        is_new = addrinfo not in self.services
        self.services[name][addrinfo] = time.time()
        if is_new:
            try:
                self.on_service_added(name, addrinfo)
            except Exception:
                self.logger.exception('error executing service add callback')
updates the service's keep-alive time stamp
dataset/ETHPy150Open sccn/SNAP/src/rpyc/utils/registry.py/RegistryServer._add_service