Newsgroups: comp.mail.misc
Path: utzoo!utgpu!watserv1!watcgl!imax!dave
From: dave@imax.com (Dave Martindale)
Subject: Re: Short expiration on comp.mail.maps?
Message-ID: <1990Jul17.175636.9443@imax.com>
Organization: Imax Systems Corporation, Oakville Canada
References: <591@dptspd.sat.datapoint.com>
Date: Tue, 17 Jul 90 17:56:36 GMT

In article <591@dptspd.sat.datapoint.com> lcz@dptspd.sat.datapoint.com (Lee Ziegenhals) writes:
>Several of the maps that I have received lately have had an expiration date
>that is less than 24 hours after the posting date.  This caused the map files
>to be expired and deleted before pathalias ran.
>
>I have modified my crontab so that pathalias runs before my nightly expire.
>However, I have lost several updates because of the problem.  Was this
>intentional?  If so, why do the maps need to be expired so quickly?  Aren't
>the maps generally valid for about a month, and therefore shouldn't the
>expiration period be about a month?

One very common way of dealing with the maps is to feed them to a processing
script via a dummy site entry in the news sys file.  For example, 
(this is an entry for C news, but B news is quite similar):

extractmap:comp.mail.maps,!comp.mail.maps.ctl/world,can,local::/var/map/extractmap %s

In my case, the "extractmap" script gets rid of the news article header,
and places the contents of the article in a standard directory.  Because
this happens as each article is processed, the copy of the article that
ends up in /usr/spool/news is useful only for feeding to other sites
downstream; it is not used locally for pathalias.  Thus, it can safely
be expired in a few days.

The advantage of this method is that at any given time, you have a
directory full of the most-recently-received version of each map.
There are no duplicates due to old unexpired articles.  If one of
this month's entries did not make it here, last month's is used instead -
that's better than having no data at all for a whole contry or province
or state.

So, I suspect that the rapid expiry date was probably a mistake - the maps
should stay around for at least a few days to provide for batched transmission
to other sites.  But for many sites, the expiry time does not need to be
anywhere near a month.

How many people run pathalias directly from the news articles in /usr/spool?
Is this common?