Re: Why not auto-config of "store_avg_object_size"?

On Mon, 27 Mar 2000 10:14:17 -0700, Duane Wessels wrote:

>On Mon, 27 Mar 2000, Steve Snyder wrote:
>
>> Given a mature cache, why can't Squid (v2.3S2) configure itself rather
>> than using the static store_avg_object_size value?
>>
>> I understand why this config option is needed when a cache is first
>> created. But once a cache has been filled to, say, the cache_swap_low
>> percentage, Squid should be able to determine for itself the
>> store_avg_object_size value.
>>
>> Having Squid do its own adjustment (at run and reconfigure times)
>> would avoid what I find myself doing periodically: adjusting the
>> store_avg_object_size value to match the reality of the cache storage.
>
>In 2.3, store_avg_object_size is only used for cache digest size estimations.
>Its probably obsolete, and could be removed entirely.
>
>Why do you feel you need to keep changing it?

Well, I don't know that I "keep" changing it but I have done it twice
in 6 months of using Squid.

My understanding is that it used is estimating the number of bits kept
in memory (for using in tracking files in the cache). Further, my
understanding is that having store_avg_object_size reflect the real
world keeps Squid for wasting memory on too many bits and prevents
it having too few to track all the cache files.

I started out with the default (store_avg_object_size = 13KB), then
adjusted it to 8KB when I saw that that was the actual average size of
the objects in the cache. The average size has since drifted up to
9KB/object so I updated squid.conf to reflect that. That's 2 changes
from the default.

Is my understanding of store_avg_object_size incorrect?

*** Steve Snyder ***
Received on Mon Mar 27 2000 - 10:51:11 MST