Re: Does Squid beat the rest?

On Fri 12 Sep, 1997, Gregory Maxwell <nullc@nightshade.z.ml.org> wrote:
> Well, there IS a difference. With squid you can tune the refresh rules
>with regexes.. Most cache software is simply on or off. Squid is VERY
>flexible.. (Dont IMS images for 6 hours, except known weather sites, while
>IMSing HTML every 60seconds, cache those webcounters even the cgi-bin
>ones, etc.) Most commercial packages cant do that.. And from the money you
>could spend on a commercial product you could pay someone to fine tune
>and modify squid to your needs.. And if your modifications are sutiable

On the whole, I'm inclined to agree with Stephane. We've done some
tuning, and you do perhaps get better results (slightly) if you've got
a smaller cache. But otherwise just keeping everything for longer can
benefit.

The controls available in the commercial Netcache are very similar
to that available in Squid, for example:

TTL Pattern

Description

Specifies the TTL (time-to-live) for objects based on URL regular expressions.

NetCache searches the list of URL patterns in the order in which they
are listed. You can specify the TTLeither as an absolute value or as
a percentage of the object's age.

To use this feature, specify a regular expression that represents the
group of URL's for which you want to create a TTL pattern. Then enter
one or more of the following characteristics:

Absolute TTL in minutes

An age Percentage and Max TTL. The object's TTL its default TTL
multiplied by the percentage specified, up to a maximum of the Max TTL
specified.

Notes

If you specify a percentage factor, list it last on the line. If the
value is positive (non-zero) and the object metadata includes a
last-modified timestamp, NetCache sets the TTL as the given percent of
the difference between the current time and the last-modified time.

If the percentage factor is not used (for example when an object has
no last-modified timestamp), NetCache checks the absolute TTL value
and uses it if the value is non-negative.

A negative absolute TTL value in conjunction with a positive
percentage factor causes NetCache to set the TTL from the pattern
match if a last-modified timestamp is present.

If neither the absolute TTL nor percentage factor settings result in a
TTL for the object, NetCache uses the default TTL from the Default TTL
(FTP, Gopher, HTTP) configuration option.

>for a general audience, you could submit them back to the development, and
>be admired as a internet-savvy company. (I would certantly choose a
>company who contributes to such products)

obviously some smaller companies won't have the experienced
code-hackers nor the time to do this. That's a key place where
commercial products come in useful - if you absolutely have to have
something that works now.

We're doing a bit of both at the moment, because although we like to
hack code we do also have services to provide!

-- jrg.
Received on Fri Sep 12 1997 - 08:10:33 MDT