Re: PRIORITY stream error?

Kazuho Oku <kazuhooku@gmail.com> Wed, 06 March 2019 22:36 UTC

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From: Kazuho Oku <kazuhooku@gmail.com>
Date: Thu, 07 Mar 2019 07:36:34 +0900
Message-ID: <CANatvzxghmoCbrVEYw6BkLt99-i8p+AfNnaqnbeR6m8TkuZBeA@mail.gmail.com>
Subject: Re: PRIORITY stream error?
To: Martin Duke <martin.h.duke@gmail.com>
Cc: IETF QUIC WG <quic@ietf.org>
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2019年3月7日(木) 5:59 Martin Duke <martin.h.duke@gmail.com>:
>
> the very end of Section 4.2.3 of quic-http says:
>
>    PRIORITY frames received by a client MUST be treated as a stream
>    error of type HTTP_UNEXPECTED_FRAME.
>
>
> Elsewhere, this kind of thing is a connection error.

I am not sure if I agree with the observation. IIUC, the general
approach is to use stream errors when the error does not affect the
entire connection.

It is reasonable for a client to respond with a stream error when it
observes a PRIORITY frame on a *request* stream.

That said, I agree that it should be a connection error when the
client receives a PRIORITY frame on a control frame. That's because we
cannot have a stream-level error for a control stream, because the
stream can never be closed. I think that's what is missing in the
text.

FWIW, we do have this "if the error is X then it's a stream-level
error, or if the error is Y then it's a connection-level error" type
of handling. See section 3.2.2 for an example.

> Making this a  stream error seems problematic; if otherwise valid, if this goes out on the control stream a stream error may bring everything down anyway?
>
> Should this be a connection error, or am I missing something?



-- 
Kazuho Oku