ietf-nntp Second message from Mike Castle

[Chin Chee-Kai]

On Wed, 19 Jul 2000, Mike Castle wrote:

> Maybe I missed it, but is LAST guaranteed to always be the same article
> number in a group?

Not guaranteed.

     Because articles can be removed and added, the results of
     multiple LAST and NEXT commands MAY not be consistent over the
     life of a particular NNTP session.

(Page 17 of draft-10)



> GROUP foo
> LAST
> (wait a few minutes)
> LAST
> 
> Are you sure you will get the same article?  If a new article came in, and
> the server connection recognizes it, might it grab the newest last article?
> 
> If so, then LAST 10, LAST 9, LAST 8, new article arrives, LAST 7, oops
> skipped an article.

You meant "NEXT" actually.  Your example above can happen even
at present.  The proposed "step" argument for "NEXT" and "LAST"
allows for a flexible "reset" of the CAP whenever the client is 
confused or thinks it is out-of-sync with the server, particularly
with regards to the first (oldest) and last (latest) articles.
Additionally, it also allows for movement of CAP other than 1
physical article at a time, though Russ' point about modern
newsreaders grabbing full listings is also true.



Cheers,
CK