[news.software.nntp] Question about protocol

cctimar@athena.cas.vanderbilt.edu (Cary Timar) (03/05/91)

It seems (please correct me if I am wrong) that the nntp protocol for
transferring news from machine A to machine B is something like:

A: ihave <x>
 B checks history file, doesn't find <x>
B: sendme <x>
 A sends <x>
 B receives <x>
 B adds <x> to log and history files
 B checks header of <x>, finds Newsgroups: misc.boring.drivel
 B checks sys file, realizes it doesn't carry misc.boring.drivel
 B removes <x>

Later, B talks to C.

C: ihave <x>
 B checks history file, finds <x>, &c.

Obviously, if <x> were not logged, C would now send <x> to B, which would
then have to throw it out again.

There is a problem, though.  We have very limited disk space, so we carry
only a small selection of news groups ( < 50 ).  Our upstream site carries
almost everything.  Thus, although our news spool directory only takes up
~12M, our history files take up another 20.  (my estimate - I'm
subtracting a random number from the space history.pag claims to take up)

The only solution appears to be asking our upstream site to customize its
sys file so as to not send us groups we don't want.  This will, however,
make it more difficult to add new groups - we will have to hassle them for
every add.

Is there any way around this?


A comment on the protocol:
If the exchange began with a sendsys, then the sending site would have to
do the newsgroup checking, rather than the receiver, but less would have
to be transmitted, so it might pay off.

I realize that I may not understand the existing protocol correctly, and
also that changing established protocols is a difficult proposition.  If,
however, somebody is working on a revision of the protocol, this would be
my suggestion.
-- 
	-- Cary Timar, Mathematics Department, Vanderbilt University
	   Life is like a metaphor, ... :-)