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Re: Drawbacks of persistent connections

From: J.P. Martin-Flatin <martin-flatin@epfl.ch>
Date: Tue, 16 Jun 1998 01:16:09 +0200
Message-Id: <199806152316.BAA21201@tcomhp31.epfl.ch>
To: Jim Gettys <jg@pa.dec.com>
Cc: http-wg@cuckoo.hpl.hp.com
On Mon, 15 Jun 1998 10:31:25 -0700, Jim Gettys wrote:
> 
> > Presumably, the timeout of persistent connections will be longer than
> > the TCP connection timeout (that is, the recommended time to maintain
> > TCP TIME_WAIT state, generally 4 minutes). So even though the
> > technique used for the attack is the same, the effect will be
> > amplified in the case of persistent connections with long timeouts.
> 
> No, actually, most of the benefit from persistent connections appears
> to be in the first 30 seconds to a minute...
> 
> I don't think many busy servers will likely keep that long a timeout,
> even with persistent connections.  Mogul's research showed that most
> the value for "click ahead" occurs in the first few minutes, so a
> reasonable timeout for a busy server (one which will likely have to
> time out connections at all) is likely shorter than the TCP TIME_WAIT
> state.

Do you refer to:

    Jeffrey C. Mogul. "The Case for Persistent-Connection HTTP".
    WRL Research Report 95/4, Digital, Palo Alto, CA, USA, May 1995.

or one of its variants (Proc. WWW2 and Proc. SIGCOMM'95)?

Jean-Philippe Martin-Flatin
Received on Tuesday, 16 June 1998 09:14:29 EDT

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