Re: cache Question

On Sat, 17 May 2003, Rodsak Promrattanakul wrote:

> >>Question:(cache_mem&cache_dir) Hit_ratio is not vary cache_mem size ?
> >Ans:Not by much.
>
> What do you mean ? and why ?
> I think that it is absolute not vary . My reason is however every hit's
> object is in disk , so if object is not found in memory , it ' ll found in
> disk.

The hitratio does vary depending on your cache_mem setting, but not by
much.

hit ratio includes both disk and memory hitratio. Not all objects are
stored on disk (primarily negatively cached entries).

> >If your request load is higher than what the disk cache can sustain
> >then you should either fix the disk cache or run without a disk
> >cache.
>
> And what 's example-case of "request load is higher than what the disk cache
> can sustain" ?

When system performance degrades below acceptable levels when your disk
cache has been filled, and you have verified this is not due to memory
shortage.

Regards
Henrik
Received on Sat May 17 2003 - 02:49:55 MDT