Re: [squid-users] Cache_mem settings

On 13.03.2012 23:44, Peter Gaughran wrote:
> Hi folks,
>
> We're in a large-number-of-users, high bandwidth/usage situation
> (average 80 gigs per hour during business hours) and so have opted
> for
> a couple of new proxies (one for fail-over) which we're about to make
> 'live'. Currently, our cache_mem and cache_dir look like the
> following
>
> cache_mem 23424 MB
> cache_dir aufs /cache1 183000 32 256
> cache_dir aufs /cache2 183000 32 256
> cache_dir aufs /cache3 183000 32 256
> cache_dir aufs /cache4 183000 32 256
>
> With internal testing (from a team of 5!), of course, everything is
> fine. I'm concerned about what will happen when we roll them out, or
> if there's something (blindingly) obvious we might have missed or
> that
> could be tweaked.

Don't forget the 10-15 MB of RAM index per GB of total cache space.
(~11 GB RAM index).

Each of those live transactions making up those ~20MBps will also
consume a ~64KB or more of RAM.

All of that *plus* cache_mem needs to fit into the available box RAM.
By my rough calc that is over 35GB of RAM needed on each box.

Amos
Received on Tue Mar 13 2012 - 11:32:24 MDT