Surely your application/serving process is able to handle the request burst coming from any single user ? (If not, you have a bigger problem to solver first).

Surely your application/serving process is able to handle the request burst coming from any single user ? (If not, you have a bigger problem to solver first). If so, I don't quite see why queueing is discussed as an option at all. Queueing means extra latency and worse user experience (not to mention DoS potential). What you should be discussing instead is how to (auto-)scale your app and infrastructure to handle your users' requests.