[5563] in www-talk@info.cern.ch

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Re: holding connections open: a modest proposal

daemon@ATHENA.MIT.EDU (Gary Adams - Sun Microsystems Labs)
Wed Sep 14 01:14:49 1994

Date: Wed, 14 Sep 1994 07:05:29 +0200
Errors-To: listmaster@www0.cern.ch
Errors-To: listmaster@www0.cern.ch
Reply-To: Gary.Adams@east.sun.com
From: Gary.Adams@east.sun.com (Gary Adams - Sun Microsystems Labs BOS)
To: Multiple recipients of list <www-talk@www0.cern.ch>

> From www-talk@www0.cern.ch  Mon Sep 12 18:28:44 1994
> 
> In article <9409121903.AA21560@dxmint.cern.ch>, David Kristol writes:
> > There has been some discussion here about keeping connections open
> > between client and server after a transaction is complete.  I don't
> > recall seeing a resolution, however, so I want to put forth what I
> > think is a simple solution, and I don't recall seeing anything
> > comparable proposed.
> >
> 
> On the www-speed alias we discussed this a couple of months ago.  One 
> of the  (simple) solutions we came up with was suggested by Gary Adams. 
>  He suggested adding a Pragma: Keep-connection header.  The behaviour 
> goes something like:
> 
> 1) Client sends "Pragma: Keep-connection\n" along with the rest of the headers.
> 2) If the server supports this pragma, in the reply headers to the 
> client, it includes "Pragma: Keep-connection\n" (real protocol negotition)
> 
> At this point, either party can terminate the connection.  Generally, 
> the client will terminate the connection after it has retrieved all of 
> the pieces of the document being viewed (suggested behaviour) or the 
> server will terminate the connection based on inactivity by the client 
> or server load.
> 
> Code changes to support this on both the server and the client are very 
> minimal.

The source changes on the server side are trivial. The client side 
changes are a bit trickier, because the Content-Length bytes need
to be counted (which is a good thing to do anyway). We sent the
client and server mods off to NCSA a little while ago, but they were
too late for the next release train.

> 
> We tended to stay away from MGET (as valuable as it may be) or other 
> new methods as those should really be part of the next HTTP definition. 
>  The Keep-connection pragma allows good interop with virtually no 
> changes to clients while addressing the basic problem of numerous 
> session setups retrieving a single document.  I think some people are 
> working on reference implementations now.
> 
> I haven't seen any complete digests of the www-speed alias.  Can 
> somebody give a pointer?
> 
> John
> 

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