SETTINGS_ENABLE_HTTP2_PRIORITIES default value | Re: Setting to disable HTTP/2 Priorities

> The aim is to maintain todays default behavior of endpoints supporting H2.
> This is achieved by defining the initial value of the setting as 1;
> endpoints "opt out" by sending 0.
> 
>Do you think we have mis-specced this compared to our aim?


There is  "If a client or server does not send the setting, the peer 
SHOULD NOT make any assumptions about its support for HTTP/2 priorities.".

https://datatracker.ietf.org/doc/draft-lassey-priority-setting/?include_text=1

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3.  The SETTINGS_ENABLE_HTTP2_PRIORITIES SETTINGS Parameter

   This document adds a new SETTINGS parameter to those defined by
   [RFC7540], Section 6.5.2.

   The new parameter name is SETTINGS_ENABLE_HTTP2_PRIORITIES.  The
   value of the parameter MUST be 0 or 1 to indicate not supporting or
   supporting HTTP/2 priorities respectively.  If either side sends the
   parameter with a value of 0, clients SHOULD NOT send priority frames
   and servers SHOULD NOT make any assumptions based on the presence or
   lack thereof of priority frames.  If both sides send the parameter
   with a value of 1, then both parties MAY use HTTP/2 priorities as
   they see fit.  A sender MUST NOT send the parameter with the value of
   0 after previously sending a value of 1.  If a client or server does
   not send the setting, the peer SHOULD NOT make any assumptions about
   its support for HTTP/2 priorities.
-------------

This section indicates that default value is undefined, because it says
that if SETTINGS_ENABLE_HTTP2_PRIORITIES is not seen, the peer SHOULD NOT 
make any assumptions about other ends support for HTTP/2 priorities.

-------------
4.1.  A New HTTP/2 Setting

   This document registers an entry in the "HTTP/2 Settings" registry
   that was established by Section 11.3 of [RFC7540].

   Name: SETTINGS_ENABLE_HTTP2_PRIORITIES

   Code: 0xTBD

   Initial Value: 1

   Specification: This document
--------------

If initial value for SETTINGS_ENABLE_HTTP2_PRIORITIES is really 1,
then peer may assume that other ends supports HTTP/2 priorities
until SETTINGS_ENABLE_HTTP2_PRIORITIES is seen.

So there is inconsistence between chapters.

/ Kari Hurtta

Received on Wednesday, 31 July 2019 19:11:18 UTC