Subject: Keep-Alive and 'max'

From: Martin Thomson <[email-masked]>
Date: Fri, 23 Mar 2012 14:57:15 -0700

I'm just going through the motions of resurrection for the Keep-Alive
header [1], which might be oxymoronic.  A question arose that we
thought might benefit from some discussion.

The Keep-Alive header, as originally documented, has a 'max'
parameter.  I've even seen it produced by some implementations (Apache
did this once).  This parameter limits the use of the connection to
'n' requests in total.

Having seen this in the wild makes me a little reluctant to just
deprecate this out of hand.  However, the only conceivable use I can
think of is to prevent clients from pipelining a bazillion[2] requests
to a server.  But there are better defenses for that, namely summary
disconnection.  On the contrary, rather than being useful, I tend to
think that this is very much un-useful, and could even be discouraged.

Does anyone have a use for ``Keep-Alive: max=<n>'' ?  Or can it be
deprecated safely?

--Martin

[1] http://tools.ietf.org/html/draft-thomson-hybi-http-timeout-01
[2] spell check fact of the day: pipelining is not a word, but bazillion is.

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From: patrick mcmanus <[email-masked]>
Date: Sat, 24 Mar 2012 18:20:33 +0100

On 3/23/2012 10:57 PM, Martin Thomson wrote:

> to a server.

right, and fwiw on friday I commited code to mozilla to honor the max 
header when considering pipeline depth. It shows up quite commonly on 
apache sites, though I don't think it is really to the server's 
advantage to ever send it.

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From: Martin Thomson <[email-masked]>
Date: Sat, 24 Mar 2012 14:03:42 -0700

header when considering pipeline depth. It shows up quite commonly on
apache sites, though I don't think it is really to the server's advantage
to ever send it.

That is the main reason I didn't think it would be that useful. But, if it
us in use, then I see no reason to withhold the function. I'll keep it in
the doc and you will then have a referenceable specification.

--Martin