RE: [squid-users] Cache distribution algorithm. Please enlighten me.

From: Hermann Strassner <hermann.strassner@dont-contact.us>
Date: Tue, 28 May 2002 08:48:46 +0200

> Thank you for your reply, but or my english is very very bad or my
> original question remains unanswered: why such a "unbalanced" distribution
> of objects over the directories, and is it suposed to be like this?

The directories are filled with files, first dir1 with 256 files, then dir2
with 256 files, and so on.
When the cache is full or when files are replaced squid distributes it among
the used directories. If you have much more dirs than needed, they are never
used.
This is no problem, since access to this directories is fast, as long as
there are no more than 256 files in it.

> Fill up 00/00 directory (till some amount of data) , then fill up
> 00/01 directory (till same ammount of data), and so on..

You are right. But where is your problem?
The caches are not filled to a size, but to 256 files each, regardless of
the size of the files.

> So, is this behaviour better than balancing objects over all directories?

I think it is much easier, and there is no disadvantage, as long as you
garantee that there are not too much files in one directory.

Hermann

PS:
> For instance, why not use something kind of :
> TOTAL_DIR_NUMBER = 16 L1 * 256 L2 = 4096 directories.
> 1rst object goes to 00/00, 2nd goes to 00/01, third goes to 00/02 ...
> 4097nth object would go again to 00/00 ...

If you delete or replace objects this would not be so easy as the other
algorithm.
Received on Tue May 28 2002 - 00:48:49 MDT

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