Re: When to make objects uncacheable ?

> Well, actually the current hit rate is zero.  Due to sizing
> problems we have had to turn off caching a few weeks ago.  That's
> why I found out about this list, and also why I wrote some code to
> analyze 600MB of log files.  I'm looking to implement a multi-level
> cache, distributed over three sites, but today I am just collecting
> data to model the sizing issues.

We have a techreport:

	http://www.iet.unipi.it/~luigi/caching.ps.gz

which discusses some issues in the relation between cache size and
hit rate.

Actually, we have also done some simulations on the performance of
hierarchical and/or cooperating caches; a report on that is not
available yet, but the bottom line is the following:

N cooperating caches (a la Harvest) with disk capacity D each work
almost as a single cache with N*D disk space (for N not too large,
let's say N < 10).  The communication between caches is a small
fraction of the overall traffic (because it only affects documents
which are accessed more than once).

	Luigi
====================================================================
Luigi Rizzo                     Dip. di Ingegneria dell'Informazione
email: luigi@iet.unipi.it       Universita' di Pisa
tel: +39-50-568533              via Diotisalvi 2, 56126 PISA (Italy)
fax: +39-50-568522              http://www.iet.unipi.it/~luigi/
====================================================================

Received on Tuesday, 20 August 1996 11:07:14 UTC