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Re: When to make objects uncacheable ?

From: Tai Jin <tai@hplb.hpl.hp.com>
Date: Tue, 20 Aug 1996 10:23:09 -0700
Message-Id: <199608201723.AA077551789@nexus.hpl.hp.com>
To: Chris.Hull@fmr.com
Cc: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com, ircache@nlanr.net
> That's what I'm seeing as well.  The best I could hope for would be
> 37% of the URLs, which would account for 48% of the data.  And this
> assumes that none of the pages have expired (which I can't easily
> see from the logs) within the week.
>
> What I did notice that as the number of logs analyzed increase, the
> potential hit rates did get better.  When I looked at one day, I
> calculated that I should only be able to get a 28% hit rate(URLs).
> With two days data in cache, I should be able to get a 33% hit
> rate.  One week - 37%.
>
> The relationship is not linear with respect to time, and I expect
> to see diminishing returns, but I imagine that if the cache is
> large enough to store all accesses for a month, the hit rate would
> increase even higher.  I could try to analyze a month's worth of

Of course, it depends on how long you set your TTLs and how long ago
the modified times are.  I suspect that with longer TTLs you'll see
more IMS and REFRESH requests (due to users hitting the reload
button), which is actually not a bad thing since you're still saving
bandwidth over a clean MISS.

...tai
Received on Tuesday, 20 August 1996 10:24:59 EDT

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