Re: [NNTP] Article Reinstatement
Julien ÉLIE <[email protected]> Fri, 13 May 2011 19:06:11 +0200
| Newsgroups | gmane.ietf.nntp |
|---|---|
| Organization | TrigoFACILE -- http://www.trigofacile.com/ |
| Message-ID | <[email protected]> |
Hi Sabahattin,
> If a client should not be aware that an article has been removed
> pending reinstatement, it has no reason to suspect that the low
> watermark will ever decrease.
The low watermark can not decrease.
> Example: news.test has 5 messages, min=3D1 max=3D5. Article 1 is
> removed. Server indicates on group entry to news.test, min=3D2 max=3D5
> no=3D4. The client updates its counters to indicate that article 5 was
> the last article seen. Article 1 is replaced. Client connects,
> server indicates min=3D1 max=3D5 no=3D5. How is the client to ensure t=
he
> retrieval of article 1?
It is not an RFC-compliant behaviour.
min could not have been set to 2.
RFC 3977, Section 6.1.1.2:
o Articles may be reinstated in the group with the same article
number, but those articles MUST have numbers no less than the
reported low water mark (note that this is a reinstatement of the
previous article, not a new article reusing the number).
[...]
No similar
assumption can be made about the high water mark, as this can
decrease if an article is removed and then increase again if it is
reinstated or if new articles arrive.
> The low watermark may certainly indicate its
> presence, but it can hardly assume that an article was reinstated
> simply because on this occasion min=3D1 is the smallest value seen; the
> article numbered 1 may already have been fetched under normal
> conditions, or the heuristic will not work at all if group expiration
> on criteria other than number of articles has occurred, for
> instance.
>
> Does anybody have any ideas?
I do not understand your point.
Wouldn't it rather be:
news.test has 5 messages, min=3D1 max=3D5 count=3D5
1. remove #1
min=3D1 max=3D5 count=3D4
2. reinstate #1 and remove #3
min=3D1 max=3D5 count=3D4
So a client that comes between action 1 and action 2 will never see #1;=20
it won't ask for #1 afterwards because the high water mark is 5. The=20
same way as a client coming after action 2 will never see #3.
But is it really a problem?
--=20
Julien =C9LIE
=AB Il faut que j'en parle =E0 notre chef ; ce n'est pas normal que des
Romains bravent les dangers de la for=EAt, surtout quand les dangers,
c'est nous ! =BB (Ast=E9rix)