Re: Setting to disable HTTP/2 Priorities

Willy Tarreau <> Fri, 26 July 2019 03:22 UTC

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Date: Fri, 26 Jul 2019 05:19:12 +0200
From: Willy Tarreau <>
To: Brad Lassey <>
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Subject: Re: Setting to disable HTTP/2 Priorities
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Hi Brad,

On Thu, Jul 25, 2019 at 02:49:52PM -0400, Brad Lassey wrote:
> Hi all,
> Lucas and I put together a draft to capture at least one of the ways
> forward that were identified at the priorities side meeting yesterday
> morning. Please have a look.

While I think that's a very wise approach, I think it would have more
success if it doesn't change the default behaviour. I mean, some
developers on both sides have gone through great length implementing
priorities and expecting now that they should suddenly have to add
extra code to continue to use them might be difficult to accept.
Conversely, all those who didn't implement them would have a great
incentive to add a few lines of code to signal their lack of support
and immediately expect a better experience. Thus I think priorities
should remain enabled unless signaled as disabled by this new setting.

And for having been late to implement them into haproxy (still not
present), I'd definitely adopt this proposal as a temporary measure
if it helps improve user experience!