Re: [Technical Errata Reported] RFC7234 (5564)

[Mark Nottingham <[e-mail]>]

REJECT. Extensions are explicitly allowed to override requirements, and making this a SHOULD would be too confusing (as many would read it as "optional").



> On 27 Nov 2018, at 10:37 pm, RFC Errata System <[e-mail]> wrote:
> 
> The following errata report has been submitted for RFC7234,
> "Hypertext Transfer Protocol (HTTP/1.1): Caching".
> 
> --------------------------------------
> You may review the report below and at:
> http://www.rfc-editor.org/errata/eid5564
> 
> --------------------------------------
> Type: Technical
> Reported by: Bruce Adams <[e-mail]>
> 
> Section: 4.2.4
> 
> Original Text
> -------------
> A cache MUST NOT send stale responses unless it is disconnected
>   (i.e., it cannot contact the origin server or otherwise find a
>   forward path) or doing so is explicitly allowed (e.g., by the
>   max-stale request directive; see Section 5.2.1).
> 
> Corrected Text
> --------------
> A cache SHOULD NOT send stale responses unless it is disconnected
>   (i.e., it cannot contact the origin server or otherwise find a
>   forward path) or doing so is explicitly allowed (e.g., by the
>   max-stale request directive; see Section 5.2.1).
> 
> A cache MAY send stale responses if a cache-control extension for
> stale content such as "stale-while-revalidate" is used 
> (see RFC5861).
> 
> Notes
> -----
> The original text seems to conflict with https://tools.ietf.org/html/rfc5861#section-3
> 
> 3.  The stale-while-revalidate Cache-Control Extension
> 
>   When present in an HTTP response, the stale-while-revalidate Cache-
>   Control extension indicates that caches MAY serve the response in
>   which it appears after it becomes stale, up to the indicated number
>   of seconds.
> 
>     stale-while-revalidate = "stale-while-revalidate" "=" delta-seconds
> 
>   If a cached response is served stale due to the presence of this
>   extension, the cache SHOULD attempt to revalidate it while still
>   serving stale responses (i.e., without blocking).
> 
> See also https://stackoverflow.com/questions/53324538/rest-low-latency-how-should-i-reply-to-a-get-while-an-upload-is-pending
> 
> Instructions:
> -------------
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> 
> --------------------------------------
> RFC7234 (draft-ietf-httpbis-p6-cache-26)
> --------------------------------------
> Title               : Hypertext Transfer Protocol (HTTP/1.1): Caching
> Publication Date    : June 2014
> Author(s)           : R. Fielding, Ed., M. Nottingham, Ed., J. Reschke, Ed.
> Category            : PROPOSED STANDARD
> Source              : Hypertext Transfer Protocol Bis APP
> Area                : Applications
> Stream              : IETF
> Verifying Party     : IESG

--
Mark Nottingham   https://www.mnot.net/