Re: Caching

Vincent.Cate@furmint.nectar.cs.cmu.edu Mon, 06 December 1993 01:41 UTC

Received: from ietf.nri.reston.va.us by IETF.CNRI.Reston.VA.US id aa20828; 5 Dec 93 20:41 EST
Received: from CNRI.RESTON.VA.US by IETF.CNRI.Reston.VA.US id aa20824; 5 Dec 93 20:41 EST
Received: from mocha.bunyip.com by CNRI.Reston.VA.US id aa18254; 5 Dec 93 20:41 EST
Received: by mocha.bunyip.com (5.65a/IDA-1.4.2b/CC-Guru-2b) id AA01647 on Sun, 5 Dec 93 18:59:24 -0500
Received: from FURMINT.NECTAR.CS.CMU.EDU by mocha.bunyip.com with SMTP (5.65a/IDA-1.4.2b/CC-Guru-2b) id AA01643 (mail destined for /usr/lib/sendmail -odq -oi -fiafa-request iafa-out) on Sun, 5 Dec 93 18:59:18 -0500
Date: Sun, 5 Dec 1993 18:47-EST
Sender: ietf-archive-request@IETF.CNRI.Reston.VA.US
From: Vincent.Cate@furmint.nectar.cs.cmu.edu
To: iafa@bunyip.com
Subject: Re: Caching
Message-Id: <755135250/vac@FURMINT.NECTAR.CS.CMU.EDU>

I think Alex is very much like what you are looking for.

Alex is a filesystem that gives you access to anonymous FTP files.  It
does do caching of files.  If the size of the file and the date last
modified have not changed, Alex assumes that the cached copy is still
good.  I don't know of any cases where this has been a problem.  The
real question is how often do you want to check that your cached data
is current.  

You can find out more about Alex by looking at:
   alex.sp.cs.cmu.edu:doc/usenix.wofs92.ps

and there is a usenix.wofs92.txt for the underpriviledged.  :-)

You can also set up a server.  It really is not very hard to set up as
it is just a user level NFS server.  Check out what is in the "src"
directory.

With Alex you can just do a:

>cd /alex/edu/cmu/cs/sp/alex/doc
>more README

After that the README file will be cached (probably for months
after the last time it is used if you have a reasonable amount
of disk).

Cheers,

  -- Vince