RE: REFUSED_STREAM => RETRY_STREAM (editorial) was: RE: hpack table size 0

I think the thing to clarify is the distinction between the stream and the request.  REFUSED_STREAM means that the *stream* is unacceptable to the server (for some reason), regardless of the request that it might have been carrying.  The server is, in fact, "unwilling" to open a stream at this time, so the name is accurate.  The client isn't told (but by the time it sees the RST_STREAM, hopefully has seen a SETTINGS frame that lets it understand with some accuracy) why the stream is unacceptable.

However, this is a transport-layer failure, which means the *request* is safe to retry.  In IE, we have exactly the same retry behavior if a TCP connection is RST before we've received any of the server's response, even if the request itself wasn't idempotent.

-----Original Message-----
From: K.Morgan@iaea.org [mailto:K.Morgan@iaea.org] 
Sent: Friday, August 1, 2014 10:31 AM
To: martin.thomson@gmail.com
Cc: ietf-http-wg@w3.org
Subject: Re: REFUSED_STREAM => RETRY_STREAM (editorial) was: RE: hpack table size 0

Hi Martin-

Can you be more specific? Section 8.1.4 says a refused stream is safe to retry. Is there a case where the stream should be refused but not retried? If so, perhaps both refused_stream & retry_stream should exist.

-Keith


> On Aug 1, 2014, at 18:25, "martin.thomson@gmail.com" <martin.thomson@gmail.com> wrote:
>
>> On 1 August 2014 02:44,  <K.Morgan@iaea.org> wrote:
>> The definition of REFUSED_STREAM is somewhat contradictory with the 
>> definition of the word refused. The word refused is defined as: 
>> indicate or show that one is *not willing* to do something [1]. The 
>> definition of REFUSED_STREAM in Section 7 references section 8.1.4 
>> which says that a REFUSED_STREAM is safe to retry. In other words the 
>> server is actually
>> *willing* to process the stream, but *currently unable* (e.g. because 
>> the client overran settings and so the client needs to retry the 
>> stream with the new settings).
>
> I'm not sure that I agree with this assessment.  Does anyone else?
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Received on Friday, 1 August 2014 18:02:59 UTC