Re: [squid-users] adaptive refresh..

From: Alex Rousskov <>
Date: Tue, 6 Nov 2001 08:02:31 -0700 (MST)


        I suggest you use Squid without "adaptive refresh" for X days,
then CacheFlow with "adaptive refresh" for X days (or, better, in
parallel). Then see if your server logs show any performance
difference. If they do, run CacheFlow without "adaptive refresh" for X
days and compare again.

        I bet that "adaptive refresh" will not have significant impact
in your environment, especially if your server adds Last-Modified
and/or Expires headers. Keep in mind that this technique does not save
client-side bandwidth, might reduce client-side response times, might
use more server-side bandwidth, and may increase load on the server,
depending on user-access and page-modification patterns. I do not know
what you mean by "does save a lot of capacity".


On Tue, 6 Nov 2001, Klavs Klavsen wrote:

> My boss, just discovered CacheFlow.. it's a cool lean, mean fighting
> machine.. but so is squid I tell him..
> he's ready to let the two be set up, so we can compare their
> price/performance..
> Here's my problem.. I have set up squid 2.5 as an accelerator box (with the
> rproxy.patch)..
> but here comes my problem, in comparison with the cacheflow box..
> the cacheflow box, can be set up to refresh object's in the cache initially
> every 20 secs.. and then
> it adaptively - based upon how often the object actually changes it sets
> another refresh-rate.. thus saving
> capacity on the backend server..
> This is the setup I have to compete with.. on squid, I can only set an
> update interval - to min. 1 minute.. -
> and I have journalists who updates somethings.. often.. and somethings not
> so often.. and they ofcourse want the changes
> to go on the site ASAP.. this is where the adaptive refresh is good.. cause
> perhaps they have to wait up to 5 min.. the first time,
> they change a page, after a longer time.. but the next time they change
> something, the adaptive refresh has lowered the time-between-refresh
> on that object.. while maintaining the higher time-between-refresh on the
> rest of the objects..
> This does save a lot of capacity, as old - never updated pages,
> automatically gets refreshed less often..
> I was hoping something like this, perhaps was in development - or possible
> on squid? ..
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> --------------------[ I believe that... ]-----------------------
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Received on Tue Nov 06 2001 - 08:02:33 MST

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