Do not queue, but respond while booting up

[dblock]

This either involves reading request data directly or using a tiny Rack backend in parallel with the main backend and terminating it when the main backend is up.

See https://mail.google.com/mail/u/0/#label/_+Open+Source%2FHeroku/13bd7e35e149b907.

The response should be a 204 by default probably. See http://stackoverflow.com/questions/9794696/best-http-status-code-in-rest-api-for-not-ready-yet-try-again-later.

[neilmiddleton]

204 would be incorrect here as 2xx series codes are generally treated as successful requests which this is not.

I would be looking to use 504 (Gateway Timeout)

"The server was acting as a gateway or proxy and did not receive a timely response from the upstream server."

[dblock]

I think that for Heroku we absolutely do want to report a successful code or it will flag the dyno as dying. Either way, this would need to be configurable.

[neilmiddleton]

Returning status codes in the 5xx series will not have any effect on the dyno's status in the manifold. It is perfectly valid to return 500's if that is what your code decides to return.