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Re: Section 8.2

From: Jeffrey Mogul <mogul@pa.dec.com>
Date: Fri, 31 May 96 13:23:04 MDT
Message-Id: <9605312023.AA24120@acetes.pa.dec.com>
To: Ben Laurie <ben@algroup.co.uk>
Cc: HTTP Working Group <http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com>
    'HTTP/1.1 servers SHOULD maintain persistent connections and use TCPs 
    flow control mechanisms to resolve temporary overloads, rather than 
    terminating connections with the expectation that clients will retry. 
    The latter technique can exacerbate network congestion.'
    
    On a practical note; how do I distinguish between an idle client, a dead 
    client, and one that is avoiding network congestion? Should the standard 
    give some guidelines?

Actually, the real question is "how do I distinguish between an idle
client, a dead client, and one that can no longer be reached over
the network?"  (Network congestion tends to result in slow but not
totally failed communication.)

The answer to the real question is "you can't, so don't bother to try."
Treat them all the same: when you get tired of waiting, give up.  Many
servers seem to use a timeout of about 20 minutes for this.

I mean, you could use the TCP keepalive mechanism to disinguish between
idle clients and the other cases, but it's pretty pointless, and it's
not a good way to reduce network congestion.

-Jeff
Received on Friday, 31 May 1996 13:33:54 EDT

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