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From: brtmac@maverick.ksu.ksu.edu (Brett McCoy)
Subject: Re: How much of a load is nntp?
Message-ID: <1990Nov17.054512.13632@maverick.ksu.ksu.edu>
Sender: news@maverick.ksu.ksu.edu (The News Guru)
Organization: Kansas State University
References: <1990Nov15.155532.3384@ssd.kodak.com> <1990Nov16.220048.22474@engin.umich.edu>
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Date: Sat, 17 Nov 90 05:45:12 GMT
Lines: 36

In <1990Nov16.220048.22474@engin.umich.edu> stealth@caen.engin.umich.edu (Mike Pelletier) writes:

>In article <1990Nov15.155532.3384@ssd.kodak.com> dcox@ssd.kodak.com (Don Cox (253-7121)) writes:
>>Does nntp cause much of a performance hit on the system the clients are
>>getting the news from? What would be a ballpark figure for the max
>>number of clients you would want to service before considering down-
>>loading the news to a remote site?

>I'm running C-news/NNTP on a DECstation 3100, and with fifty-five connections
>at any given time, there's barely over one load point, and that's with
>about 10 news transmitters running and an AFS file server going as well.
>The CPU time is minimal -- think about it:  the process accesses and
>transmits only that which is needed, and the vast majority of time
>in an NNTP client connection is spent with the person reading the text
>that was sent, with the program doing nothing.

Something most people forget about here is the memory involved.  Each nntp
connection requires that an nntpd process be running.  If the client is even
moderately busy this involves several hundred K worth of memory being devoted
to the nntpd, which is several hundred K lost to any other process trying to
run.  Also, people reading news using nfs cause the nfs cache to get filled
with news articles instead of swap space or system or user files.  I agree
that the amount of user cpu time used by the nntpd processes is minimal, but
when you add up all of the other resources used, especially memory, which
still seems to be a valuable commodity even with 16M, news readers can impose
a serious burden on a system.  I know this for a fact because the machine
that I use is also the news host.  It not only processes all of the news, but
it does the nfs serving and nntp serving for all of the people who read news
on campus, and this causes a serious decrease in overall performance for the
machine during busy times.
--
When an eel bites your leg, and the pain makes you beg, that's a moray!
If I spent as much time on my classes as I do reading news, I'd graduate.
Brett McCoy			Computing and Telecommunications Activities
brtmac@maverick.ksu.ksu.edu	Kansas State University
