Think some microservice being used to send enormous amount of spam. You'd want to take it offline as first mitigation, then improve anti-spam measures, then re-publish the service again. The application should not disappear entirely (not use 404), perhaps use [503 SERVICE UNAVAILABLE ](https://httpstatuses.com/503): > The server is currently unable to handle the request due to a temporary overload or scheduled maintenance, which will likely be alleviated after some delay.