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Re: [DNSOP] Should we try to work on DNS over HTTP in dnsop?

Tony Finch <dot@dotat.at> Mon, 21 December 2015 13:13 UTC

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Date: Mon, 21 Dec 2015 13:13:10 +0000
From: Tony Finch <dot@dotat.at>
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Cc: dnsop@ietf.org, Mark Delany <f4t@november.emu.st>
Subject: Re: [DNSOP] Should we try to work on DNS over HTTP in dnsop?
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Paul Vixie <paul@redbarn.org> wrote:
>
> any HTTP initiator who wants out of order response processing will have
> to negotiate for it (see mogul's 2001 RID draft) and will then have new
> responsibilities for matching up the out of order HTTP responses with
> then-outstanding HTTP requests.

The current way to deal with out-of-order responses and head-of-line
blocking in HTTP is HTTP/2.

If you do DNS over HTTP then there has to be an exact correspondence
between HTTP requests and responses and DNS requests and responses -
anything else would be madness. This implies that DNS over HTTP/1 only
supports in-order pipelined queries and responses in each connection; to
avoid head-of-line blocking you need either multiple connections or
HTTP/2.

Tony.
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