Path: utzoo!utstat!helios.physics.utoronto.ca!jarvis.csri.toronto.edu!rutgers!iuvax!maytag!looking!brad
From: brad@looking.on.ca (Brad Templeton)
Newsgroups: news.software.b
Subject: Re: Dynamic "smart" expiration?
Message-ID: <68713@looking.on.ca>
Date: 29 Dec 89 04:50:57 GMT
References: <1989Dec27.033817.9953@smsc.sony.com> <1989Dec28.063932.13720@robohack.UUCP> <1989Dec28.171830.13130@smsc.sony.com> <1989Dec29.020109.16829@utzoo.uucp>
Organization: Looking Glass Software Ltd.
Lines: 31
Class: discussion

I found using the size of a file as a parameter to be useful.

My expire assigned a score to each article.  The base of the score was
the age of the file in seconds (I ignored any explicit expiry date -- I didn't
want outsiders deciding how long their pearls of wisdom would stay on my
system when I only had 3000 blocks free, thank you.)

In any group, one could add to the score based on the group, so that some
groups hung around longer than others.

In addition, I did set it so that the size of the file (multiplied by
a constant of your choice) was added to the score.

The scores were then sorted, and the files with the highest scores were
removed until enough disk space had been freed -- or rather until the
remaining disk space was my fixed allocation for news.

Adding the size made it the case that one really big article would go
instead of a dozen small ones.  This kept the average number of
days of articles kept higher than it would have been otherwise.

So Henry, there's one point of data.   I would post this very simple
expire here if people want it -- it's quite short -- but there's a lot
it doesn't do.  For one, it ignores the history file all together, and
just gets ages from stat().  It doesn't update the database or the
active file.  That means you need to run expire -rebuild every few days
to get things back in mesh.   This program controls the disk space
problem and lets the real expire keep track of the databases and active
file.
-- 
Brad Templeton, ClariNet Communications Corp. -- Waterloo, Ontario 519/884-7473