Path: utzoo!utstat!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!samsung!brutus.cs.uiuc.edu!coolidge
From: coolidge@brutus.cs.uiuc.edu (John Coolidge)
Newsgroups: news.software.b
Subject: Re: Message ID niceties
Summary: I thought of one... maybe.
Message-ID: <1989Nov24.065119.5044@brutus.cs.uiuc.edu>
Date: 24 Nov 89 06:51:19 GMT
References: <7081@ficc.uu.net> <1989Nov22.180840.1576@utzoo.uucp>
Sender: news@brutus.cs.uiuc.edu
Reply-To: coolidge@cs.uiuc.edu
Organization: U of Illinois, CS Dept., Systems Research Group
Lines: 37

In article <1989Nov22.180840.1576@utzoo.uucp> Henry Spencer writes:
>In article <7081@ficc.uu.net> peter@ficc.uu.net (Peter da Silva) writes:
>>News 2.11 PL 14 uses files of the form /tmp/Lmessage-id for lock files...
>In case anyone is planning clever software and is curious, C News does not
>create any lock based on the message-id.  We couldn't see any reason for it.

I thought of a use, but it might or might not be of value. The idea
was not to create a lock based on message-id, but rather write
incoming articles into in.coming with the message-id as filename.
This works, of course, only if you're _not_ doing C-style batching.
We're not, because I'm optimizing for propagation time and want
each article out of nntpd and into relaynews ASAP.

If you do this, you have a very good indication that article foo
has been received by your system if a batch by that name exists,
even if it's not in history. Therefore you can turn down future
ihaves and cut your dup rate.

Pluses: lower dups. Minuses: lower robustness (what if the first
copy was munged during transmission or reception), a more complicated
naming scheme, more complicated code to deal with ihaves.

In any case, I'm not likely to implement this. I'm more interested
in doing away with in.coming files altogether and piping things from
nntpd to relaynews. Yes, I know of the difficulties inherent in this.
But there are some big advantages, and I think I can see a way around
most of the major problems (albeit not a truly machine-independent
workaround...).

--John

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John L. Coolidge     Internet:coolidge@cs.uiuc.edu   UUCP:uiucdcs!coolidge
Of course I don't speak for the U of I (or anyone else except myself)
Copyright 1989 John L. Coolidge. Copying allowed if (and only if) attributed.
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