Re: HTTP/2 GREASE, Results, and Implications

Willy Tarreau <> Thu, 31 October 2019 17:18 UTC

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Date: Thu, 31 Oct 2019 18:15:59 +0100
From: Willy Tarreau <>
To: Bence =?iso-8859-1?Q?B=E9ky?= <>
Cc: Mike Bishop <>, HTTP Working Group <>
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Subject: Re: HTTP/2 GREASE, Results, and Implications
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On Thu, Oct 31, 2019 at 01:08:53PM -0400, Bence Béky wrote:
> Thanks, Willy, for pointing out the different sections of RFC7540
> concerning unknown frame types.  It seems to me that for the past few days
> Chrome (on certain channels) has been sending frames on half-closed
> (remote) streams.  It might be worth fixing that and re-running the
> experiment.  I'll circle back with results if we end up doing that.

OK. I have a pending patch ready for testing on the haproxy front which
addresses this mismatch. The only thing is that chrome beta doesn't seem
to be available on linux so I constantly have to bother other people for
testing, which takes time :-/

Regarding the impacts on our uesrs of anoyher test, I'm not much worried
of the risk to break a few sites running unfixed versions of haproxy if
a new Chrome version enables the test again; we've faced some hard to
diagnose bugs not too long ago and users are trained to disable H2 if
something really bad happens. Of course it's not desirable but it's not
as if everything definitely broke. Also our community tends to be quite
reactive when it comes to applying important fixes. Thus I full support
restarting the test ASAP :-)