Re: Changing Default News Server

[Ken Raeburn <raeburn@cygnus.com>]

Lars Magne Ingebrigtsen <larsi@ifi.uio.no> writes:

> Well, I think if we're clever we can get the operation down to hours,
> and if we do it thoroughly it might take days.  I'm probably being
> overly pessimistic, though.  I think I should just write it and see
> whether it'll be too slow to be useful.

I located the perl script I had seen before, and ran it with my .newsrc
and my nntp server.  Now, we do have a short expire time for many groups,
and we've been off the air for a couple of days, so I've got an easy test
case, but it finished translating from newsrc to message-id list (ids plus
group names totalling 2854 items) in under 30 seconds.  The reverse
translation took less time.

This is recording only the read articles.  Ticked and replied-to articles
would need to be tracked separately.  I don't think unread articles need
to be tracked.

A typical news server probably has many more articles than we do right
now, but I would guess (possibly incorrectly?) that the time required
would be more dependent on the number of articles read, not the total
available on the server.

I would expect an elisp version to be much slower than the perl code --
take this as a challenge if you like :-) -- but if it does amount to a
large number of minutes or even an hour or more, I don't think it's a big
problem as long as progress can be monitored in the minibuffer or
something.  This *shouldn't* be a common operation, and the user shouldn't
mind waiting a long time.  Heck, she could run it in batch mode.

It takes a long time to run nnml-generate-nov-databases too, but we don't
skimp on the accuracy for performance reasons. :-)

Ken

P.S.  I don't know if this perl code is considered ripe for distribution.
I can check with the author, if anyone wants to look at it.