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From: Pedro Roque Marques <roque@di.fc.ul.pt>
Newsgroups: comp.os.linux.networking,comp.unix.bsd.netbsd.misc,comp.unix.bsd.freebsd.misc
Subject: Re: TCP latency
Date: 10 Jul 1996 13:41:08 +0100
Organization: Faculdade de Ciencias da Universidade de Lisboa
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>>>>> "tedm" == tedm <tedm@agora.rdrop.com> writes:
tedm> In <31E16AF1.1568F730@lambert.org>, Terry Lambert
tedm> <terry@lambert.org> writes:
>> tedm@agora.rdrop.com wrote: ] [blah blah deleted] ] ] I have to
>> interject something here on this discussion: ] ] I feel this
>> has gotten so academic that it is meaningless. Who ] cares
>> what the latency/throughput figures are or who is winning ] the
>> current benchmark in vogue!
>>
>>
>> I would have to hazard the guess that people who design before
>> they implement, care, since a discussion of the issues is
>> important to choosing the correct approach for a design.
>>
>> It's called "engineering".
>>
tedm> I have nothing against engineering. However, I think you
tedm> missed my point, which is simply that in a real world
tedm> network there are many more factors that are uncontrolled
tedm> than what are controllable on the server itself.
tedm> One of the reasons that I feel this discussion is worthless
tedm> is that among all the numbers that people have tossed out no
tedm> one has mentioned anything about the network hardware _on
tedm> the server_ let alone the network hardware on the network
tedm> itself. (which I still maintain has a lot more effect on
tedm> perceived server performance)
I've the feeling you are still missing Terry's point (at least as I understand
it). Benchmarking can be used in two ways: to evalute a hardware+software set
behaviour in a pratical application/enviroment/use and to evaluate code/design
decisions. lmbench is more oriented IMHO to the second goal although it is
based on examples of read world problems. Discussing what tcp latency is
in groups oriented to OS design should be ok and useful even when people don't
start to take it as a "My OS is better than yours" argument.
I doubt you can draw direct conclusions from the tcp latency numbers about
which OS is better for WWW server, but you can use it to track the evolution
of a particular OS TCP for instance. The famous signature behind this argument
represents an achievement for Linux. No, i wouldn't expect non Linux people
to care a bit about that but for instance i do :-)
regards,
Pedro.