Re: The Mythical 30% Hit Rate

On Sat, Nov 20, 1999 at 06:56:37PM +0800, Miguel A.L. Paraz wrote:
> Hi all,
>
> I'm curious about the oft-quoted 30% optimal hit rate "by experience".
> Is this on requests or on bytes? I got a server that's doing 30% on requests,
> and 15% on bytes, on 9 GB of cache_dir.
>
> I'm wondering if adding 9 GB more disk will increase the byte hit rate.
> One reason it might not, is because this cache handles requests of
> downstream caches and not end-user requests.
>

On our cluster, we get ~30% bytes and ~34% requests on 45gig, I suspect there's
a sweet spot as it's pretty close to what we get on the 20gig cluster members.

If you do service downstream caches, then you don't get good statistics as
the downstream gets the client hits.

tom@interact.net.au
Received on Sat Nov 20 1999 - 05:18:58 MST