Re: ietf-nntp Backfill

"Clive D.W. Feather" <Clive@on-the-train.demon.co.uk> Tue, 17 December 1996 20:38 UTC

Received: from cnri by ietf.org id aa17282; 17 Dec 96 15:38 EST
Received: from ACADEM2.ACADEM.COM by CNRI.Reston.VA.US id aa21690; 17 Dec 96 15:38 EST
Received: (from majordomo@localhost) by academ2.academ.com (8.8.3/8.7.3) id OAA05534 for ietf-nntp-outgoing; Tue, 17 Dec 1996 14:35:44 -0600 (CST)
X-Authentication-Warning: academ2.academ.com: majordomo set sender to owner-ietf-nntp using -f
Received: from academ.com (root@ACADEM.COM [198.137.249.2]) by academ2.academ.com (8.8.3/8.7.3) with ESMTP id OAA05529 for <ietf-nntp@ACADEM2.ACADEM.COM>; Tue, 17 Dec 1996 14:35:42 -0600 (CST)
Received: from relay-11.mail.demon.net (relay-11.mail.demon.net [194.217.242.137]) by academ.com (8.8.3/8.7.1) with SMTP id OAA19887 for <ietf-nntp@academ.com>; Tue, 17 Dec 1996 14:35:37 -0600 (CST)
Received: from ball120.demon.net ([193.195.225.120]) by relay-9.mail.demon.net id ab910604; 17 Dec 96 20:20 GMT
Message-ID: <pk6vAiAMdrtyEwO2@on-the-train.demon.co.uk>
Date: Tue, 17 Dec 1996 15:07:56 +0000
To: markd@mira.net.au
Cc: Nat Ballou <NatBa@microsoft.com>, ietf-nntp@academ.com
From: "Clive D.W. Feather" <Clive@on-the-train.demon.co.uk>
Reply-To: clive@demon.net
Subject: Re: ietf-nntp Backfill
In-Reply-To: <19961217005647.12198.qmail@bushwire.mira.net.au>
MIME-Version: 1.0
X-Mailer: Turnpike Version 3.01 <81yImECxEkLwWotvkdN7a29E6a>
Sender: owner-ietf-nntp@academ.com
Precedence: bulk

markd@mira.net.au writes
>Further, backfill most cause confusion for a reader, what if:
>
>       Server                          Reader
>       ------                          ------
>T+0    new article arrives
>       allocated # 10
>T+1                                    Reader reads article 10
>                                       notes that #10 is read
>T+2    article 10 cancelled
>       
>T+3    new article arrives
>       re-allocated # 10

Uh, there seems to be a misconception here that backfilling means
reusing the numbers of cancelled articles. THIS IS NOT THE CASE.

The situation is one where the server is allocating article numbers
other than in strictly increasing order. Each number is only ever used
once, and so tracking read articles by number is a reasonable strategy.

-- 
Clive D.W. Feather    | Associate Director  | Director
Tel: +44 181 371 1138 | Demon Internet Ltd. | CityScape Internet Services Ltd.
Fax: +44 181 371 1150 | <clive@demon.net>   | <cdwf@cityscape.co.uk>
Written on my laptop - please reply to the Reply-To address <clive@demon.net>