[NNTP] Large article numbers extension

[Charles Lindsey]

In <20050726145938.GA20716 at finch-staff-1.thus.net> "Clive D.W. Feather" <clive at demon.net> writes:

>So now we're down to one basic situation: how to report a group with large
>article numbers in GROUP, LISTGROUP, LIST ACTIVE, and NEWGROUPS. Here is
>what I would propose:

>* If the client has not used the BIGNUM command, the server acts as if
>  the high water mark is 4294967295, except that NEXT fails with 401 BIGNUM
>  instead of 421 ("no next article").
>* If the client *has* used the BIGNUM command, article numbers greater than
>  the current {MC} are prefixed with a tag (e.g. a plus sign) to indicate
>  that they are too big.

>Thoughts?

The chief problem is that the old client will *never* be able to read the
recent articles in the overflowed group. That is not good.

How does that compare with the alternatives?

1. Wrap-around.

The client would get mightily confused. But, after a while, all the
articles prior to the wrap would have expired, as which point we are back
to the present situation. At that point, the client would be able to read
the group normally. Not good, but surely better than *never* seeing
articles in the group again.

2. Have a flag day.

Has anyone actually looked into how a flag day would be organized?

Presumably the server goes off line for a few hours while it renumbers all
the articles in the affected group, starting from 1 (or perhaps from
some large constant).

What does the client see when it comes back? Presumably its .newsrc file
is all wrong. Somehow it has to reset that line of its .newsrc file, at
which point it will be offered all the already-read articles in the group
as it they were new. Tedious, but manageable, and no articles are lost.
And with a bit of assistance from the server (for example, a list mapping
old numbers to new ones, or making the new numbers differ by a large
constant from the old ones, or keeping the old group around in a renamed
form, with Xref headers of old articles pointing to both groups) things
could be made almost tolerable.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
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