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Re: HTTP Session Extension draft

From: Alex Hopmann <hopmann@holonet.net>
Date: Thu, 6 Jul 1995 13:31:27 -0700
Message-Id: <199507062031.NAA21460@holonet.net>
To: Chuck Shotton <cshotton@biap.com>, http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
On July 6th, 1995 Chuck Shotton wrote:
>At 11:15 AM 7/6/95, Simon Spero wrote:
>>Most systems I use have little difficulty with 1000s of open connections,
>>as long as most are idle and the window sizes are chosen appropriately.
>About 30% of the servers on the net today can't even come close to this.
>This is a chronic problem with software that originates on the Unix side of
>the house, then migrates to other platforms. People assume that wasteful,
>inefficient implementations will be accomodated by the O/S. This is not
>true on many platforms and to design a protocol that assumes the O/S will
>accomodate lazy programmers is not responsive to the needs of a large
>number of users. Not all machines have gigabytes of swap space or thousands
>of IP connections to waste.
>>Keeping connections alive beyond the 100 seconds may not immediately give
>>a better hit-rate for trace loads- however if caching with active
>>invalidation is used, having connections open makes it much easier to
>>keep things up to date.
>This is so far away from the original intent of the HTTP protocol as to
>almost be unrecognizable. The server is supposed to be the passive entity
>in all this, with the clients actively requesting documents, maintaining
>state info, and driving the transactions. I recognize that there is a need
>for server-initiated communications. I'm just not convinced that the whole
>HTTP protocol needs to be turned on its ear to do it, and it certainly
>isn't sufficient justification to say it'll work OK on Unix.

Well frankly I'm not sure the original intent of the HTTP protocol matters
right now. The key thing is that we have discovered so major inefficiencies
with HTTP because it is based on TCP, the originators of HTTP have said
something along the lines of "you know thats a good point", and we have
found some fairly good ways to improve performance. I would also like to
point out that these performance improvements are not dependent on any Unix
kernel tweaking as you seem to imply. As a matter of fact Chuck, as you
should know I do all my development primarily on the MacOS and Windows
platforms. I encourage you not to implement it if you feel that it will not
give you any benifits on your platform.

Alex Hopmann
ResNova Software, Inc.
Received on Thursday, 6 July 1995 13:34:41 UTC

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