Retry-After, RateLimit.r parameter and example "Retry-After and slow down"

[ioggstream]

Given

• Server Behavior states:

If a response contains both the Retry-After and the RateLimit header fields,
the Retry-After field value SHOULD NOT reference a point in time earlier than the reset parameter

I Expect

• clarify the description (e.g., while in Example B.3 the Retry-After references a point in time earlier that the reset parameter, the quota is not yet fully consumed).

See also https://mailarchive.ietf.org/arch/msg/httpapi/prI-_67g4TdQJOnAP39lkU0mAyY/

TF: It would make sense to me if Retry-After has to be at least as late as
the RateLimit t= effective window when the available quota r= is zero,
but can be anything when the available quota r > 0.

Notes

• in Example B3

HTTP/1.1 429 Too Many Requests
Content-Type: application/json
Retry-After: 20
RateLimit-Policy: "dynamic";q=100;w=60
RateLimit: "dynamic";r=15;t=40

{
  "status": 429,
  "detail": "Wait 20 seconds, then slow down!"
}

[ioggstream]

🤔 Note to self, trying to making up my mind on the ongoing discussions.

Excerpt from https://mailarchive.ietf.org/arch/msg/httpapi/ZbHE4bdTTUVvbKDqLeRubj-yu1w/

I recommend [..] the Retry-After header SHOULD have a
value lower than the reset time in the RateLimit header.

-----*---------------Q---------> time
     ^               ^
Retry-After     Quota-Restored

to accommodate
situations (such as token/leaky bucket limits) where more requests can be
made before the overall limit fully resets.

🤔 t is not the moment when the quota is fully restored. The current wording is "additional quota associated with the quota policy is made available".

[fanf2]

I've been going through the draft in more detail to prepare a pull request and I noticed the scenario I suggested (Retry-After is before t= and r= is nonzero) is already described in appendix B!

So the example in Appendix B is exactly the kind of thing I was thinking of (before reading through all the examples, heh), but currently the requirement in the body of the draft disallows that example.