Re: [Doh] Support requirements for Get and Post

Patrick McManus <pmcmanus@mozilla.com> Sat, 17 March 2018 18:30 UTC

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From: Patrick McManus <pmcmanus@mozilla.com>
Date: Sat, 17 Mar 2018 18:30:18 +0000
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To: Ben Schwartz <bemasc@google.com>
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Subject: Re: [Doh] Support requirements for Get and Post
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imo normative SHOULD is a tad too strong.

One thing to note is that the 405 ought to include an allow response header
indicating what methods it can process.. so your fallback ought to be in
that set, at a minimum.

But its also possible that the other method might not meet your
requirements.. e.g. a GET is 405'd and you require an HTTP cache to meet
performance requirements - you might not use doh, or use a different
server, or whatever instead of SHOULD retry.

may is really ok imo.



On Sat, Mar 17, 2018 at 5:22 PM, Ben Schwartz <bemasc@google.com>; wrote:

> On Sat, Mar 17, 2018 at 9:47 AM, Patrick McManus <pmcmanus@mozilla.com>;
> wrote:
>
>> Overall I think the draft does an OK job of describing the merits of
>> get/post (post is more efficient but is not http cache friendly, get is
>> needed for cases like push and is more http cache friendly). If folks think
>> its imperative to have that summary in one place in the document I'm happy
>> to make that change.
>>
>> I would think most clients relying on http caches for performance would
>> use get, but if they have a DNS cache they are populating they would use
>> post. A server can choose not to implement one of these (and "method not
>> allowed" is the right response for that imo), but its limiting what clients
>> can achieve with it.
>>
>
> SHOULD clients handle a "method not allowed" by retrying with the other
> method?
>
>
>>
>> -P
>>
>>
>> On Sat, Mar 17, 2018 at 1:43 PM, Patrick McManus <pmcmanus@mozilla.com>;
>> wrote:
>>
>>> push #1: anticipate other needs of the client (as mentioned)
>>>
>>> push #2: its a different way to express additional records if that's a
>>> desirable thing (e.g. ttl granularity)
>>>
>>>
>>>
>>> On Sat, Mar 17, 2018 at 1:16 PM, Ólafur Guðmundsson <
>>> olafur@cloudflare.com>; wrote:
>>>
>>>> What is the usage case to Server push of DNS answers ?
>>>>
>>>> Olafur
>>>>
>>>>
>>>> On Sat, Mar 17, 2018 at 12:40 PM, Daniel Stenberg <daniel@haxx.se>;
>>>> wrote:
>>>>
>>>>> On Sat, 17 Mar 2018, Ólafur Guðmundsson wrote:
>>>>>
>>>>> Post MUST be supported Get MAY be supported, when GET is not supported
>>>>>> the error code retuned should be 405 (HTTP RFC 7321, section 6.5.5).
>>>>>>
>>>>>
>>>>> You didn't say this, and it is a side-note about methods, but I still
>>>>> wanted to just mention that when imlementing support for HTTP/2 server push
>>>>> for DOH, you want the server to send that as a GET so that the query string
>>>>> tells the client about the request it also sends the response to...
>>>>>
>>>>> --
>>>>>
>>>>>  / daniel.haxx.se
>>>>
>>>>
>>>>
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>>>>
>>>>
>>>
>>
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>