[NNTP] Article Numbers Becoming Invalid (RFC 3977)

[Russ Allbery]

Sabahattin Gucukoglu <mail at sabahattin-gucukoglu.com> writes:

> RFC 977 makes no special mention of article numbers being no longer
> valid, but assigns a code 430 for "Article not found".  RFC 3977 does
> away with that code, but then describes the possibility of articles
> being removed.  It doesn't say why or how.

I'm not sure that I understand.  430 is still in RFC 3977 as the return
code for ARTICLE and related commands when retrieving an article number
(or message ID) that doesn't exist.

> I'm trying to write a program that gets all articles from a group,
> articles numbered in ascending order, noting first and last reported by
> the GROUP response, and noting the minimum article number written into a
> user rc file that is updated with each invocation.
> http://get.sabahattin-gucukoglu.com/newsfetch

> Like a tool I used before, this is intended to get news into a mailbox,
> but this hand-written tool delivers them using raw SMTP that is a lot
> faster and more useful than delivering to mbox files.  Quite often I am
> getting errors from my news server about articles that disappeared but
> that are in the newsgroup's range.  Presumably, they were once valid.

> How and why do articles disappear, and what can I do about this?

Generally, it means that the articles have either expired or been
cancelled or deleted by the news administrator.  When they disappear out
of the middle of the article range, it generally means they've been
cancelled.

> Shall I just ignore errors about invalid article numbers, or try to
> enumerate article numbers?  (Most news servers don't know about the
> listgroup range operand.)

Articles that have disappeared normally never reappear.  Most news
software just treats them as if they never existed and increments the low
water mark past them.

-- 
Russ Allbery (rra at stanford.edu)             <http://www.eyrie.org/~eagle/>