Path: utzoo!utstat!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!olivey!jerry
From: jerry@olivey.olivetti.com (Jerry Aguirre)
Newsgroups: news.software.b
Subject: Re: relaynews too slow
Summary: NNTP and C news have different design goals
Message-ID: <49453@olivea.atc.olivetti.com>
Date: 25 Sep 90 04:27:26 GMT
References: <1990Sep20.212757.12868@news.arc.nasa.gov> <1990Sep23.000826.15925@zoo.toronto.edu>
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Organization: Olivetti ATC; Cupertino, CA
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In article <1990Sep23.000826.15925@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>The underlying problem is that NNTP does not take notice of the fact that
>transferring and processing articles a batch at a time is much more
>efficient than doing them one at a time.  The UUCP community learned that
>most of a decade ago, but the Internet community has generally been
>reluctant to admit that UUCP has anything to teach them.

Henry,

I think this is more a case of a square peg and a round hole rather
than NIH.  UUCP in inherently a batched operation in the sense that one
submits a job and it is processed sometime later.  That is what makes
the ihave/sendme protocol so inefficient for UUCP connections.

Adding batches, in the sense of multiple articles sent as one file, is
a natural optimization with only minor disadvantages.  The use of
compression makes batching for UUCP even more appealing.

The type of transmission used for NNTP establishes a real time
connection.  This allows for the potential to virtually eliminate the
wasted overhead of sending again an article already on the receivers
system.  NNTP lends itself to multiple feeds for a number of reasons
and the number of duplicates grows proportionally.  (It is the norm
rather than the exception for me to see the same article being offered
multiple times within a few seconds.

With B news there was little advantage to using batches (in the news
processing itself).  For most IP network connections there is little
advantage to using compression.  Therefor the advantages of eliminating
the extra overhead of the duplicate copies very much outwayed the
almost nonexistant advantages of batching.  The release of C news may
have shifted that balance but it is hardly fair to critizise NNTP
because you changed the rules.  NNTP doesn't break when one uses
batching, it just looses a couple of its advantages.  Some of us just
happen to think they are important advantages.

The performace advantage of C news seems to rest primarily on a
deliberate delaying of the processing and retransmission of news
articles.  This is at odds with the goal of many NNTP developers who
wanted to reduce the propagation delay of articles.  Obviously we are
dealing with different design goals here.  A leaf UUCP site that is
short on CPU cycles is going to have a different set of requirements
than a NNTP site with 10 neighbors and a faster CPU.  If I were such a
leaf site I would have converted to C news long ago.  As it is I am
still waiting for that "seam" to become less obvious.

				Jerry Aguirre