[leafnode-list] Moderated postings

[Matthias Andree]

Bernd Felsche <bernie at innovative.iinet.net.au> writes:

>> change its posting strategy in one of the next releases, with
>> per-server queues and perhaps optionally assigning a _single_
>> server to post upstream articles for a certain group, think
>> group-based routing if you wish.
>
> The group-based posting is desirable; especially if multiple
> upstreams support the same newsgroup.

I've so far found that leafnode trying to post to more than one server
worked out well; problems arise when some rampant site replaces the
Message-ID randomly. There MAY be reasons where replacing them is a
necessity, in such cases, there must be an unambiguous way for the site
to create the new Message-ID systematically from the old one, by
prefixing or suffixing a constant part, for example, a mailing list or
group name, but NO RANDOM and NO TIME-VARYING parts.

The site that replaced Jim's Message-ID is responsible for the
duplicates, nobody else. (Just to put that straight.)

The posting code has been lying untouched for too long and needs to be
more flexible, that's why I mentioned it in this thread, not because
leafnode is buggy.

>> Leafnode will try to post articles to moderated groups only once,
>> regardless if leafnode itself knows the moderator's address or leaves
>> the forwarding to the maintainer to the upstream.
>
> In the latter case you could unlink the posted article from
> out.going and forget about it once it's been emailed.  It's actually
> posted from "upstream" by the moderator.

Indeed it is, and fetchnews will forward the posting to exactly one
upstream server exactly once when the group is known to be moderated.

> I'm slightly familiar with the problem because we've recently
> established an NNTP server "behind" a list server for a Linux User
> Group with newsgroups reflecting the various lists as local groups.
> Articles "posted" are having to be filtered due to possible
> cross-posting (another can of worms if they're moderated).

It's simple: if ONE of the destination groups is moderated, the posting

> There's no "upstream". It server only "local" newsgroups.

> The local groups are marked as moderated with the "moderator"
> ostensibly being the mailing list (it can't be because of the
> cross-posting issue as leafnode emails only to one moderator, but
> the article is required in multiple lists).

is sent to the moderator of the leftmost moderated group in the the
Newsgroups: header, who can then approve (and crosspost) or reject the
posting - or, with multiple moderated groups, forwards it to the
moderator of the next moderated group to the right of his own, in the
Newsgroups: header.

This will obviously require special support by the list software or NNTP
gateway.

Multiple moderated cross-posted groups aren't supported too well.

> The "major" stumbling block is that leafnode won't accept postings
> from "bogus domains", yet the mailing list software does (it
> shouldn't, but it's seen as being leafnode's fault that it doesn't
> accept bogus domains). We're working on the mailing list front-end
> re-writing bogus Message-ID

To wreak havoc, with duplicates and all that Jim has just reported.

Don't - reject the mail instead.

I can split out a quick mail filter that applies the same rules to the
Message-ID as leafnode if that is desired.

Replacing the Message-ID, however bogus it was, is likely to create a
lot more problems than it solves, starting with broken threading, over
duplicates to other issues I don't know off-hand, there are sure to be
some.

> if they're obviously bogus as it has the
> potential to destroy threaded views in email as well; as well as
> "collisions" with existing articles in leafnode.

Bogus Message-IDs in mail are usually the result of an incomplete
configuration of the hosts that runs the mailer or newsreader.

> Number 3 is one significant point. If the moderator never approves,
> doesn't the "posted" article remains in out.going forever?

See above.

As long as leafnode is aware that the group is moderated, it will try to
post once, on only one server, and then remove the article from
out.going, ll. 1769ff. in fetchnews.c as of the current 20041006a
snapshot.

-- 
Matthias Andree

Encrypted mail welcome: my GnuPG key ID is 0x052E7D95 (PGP/MIME preferred)