Re: How to test cache server with historical log?

On Tue, 9 Apr 2002 maer727@sohu.com wrote:

> Hi, pals.
>
> I am using Squid 2.4 STABLE and enjoy it very much. And another idea arises.
>
> Can I use historical log files to test Squid cache hit rate?
>
> Where to download log files?
>
> What software should I use?
>
> My aim is to compare the following three algotithms: LRU, GDSF, LFUDA.
>
> Can anyone help me?

I can tell you the result of your future comparison for a typical
cache size of a correctly configured caching proxy: LRU (with a
reasonable size threshold), GDSF, LFUDA, and all other reasonable
algorithms will perform about the same.

If you have an unusual configuration such as a tiny cache, doing the
comparison may make sense. In that case, you should take special care
to use traces that contain enough information about requests and
responses and that have patterns very similar to your environment. The
results for tiny caches and other unusual configurations can be very
volatile.

You can use tcp-banger in Squid distribution (squid/test-suite/) to
replay access logs. Many origin server test suites such as HTTP
Blaster can request given URLs through a proxy. The next release of
Web Polygraph will have that functionality as well. Note, however,
that some origin server owners may be upset if you are not careful
with what kinds of requests you are replaying and how often.

Alex.
Received on Tue Apr 09 2002 - 08:26:20 MDT