Re: memory usage ...

Marc G. Fournier wrote:
>
> I have my cache set to 128MB on a 512MB machine...things are running
> *great*, we hit 10k requests over the past hour this morning...most
> impressed, considering we just turned things on...

Squids use of cache_mem is sub-optimal. Most people find that the memory
is better used as disk buffers and similar OS managed stuff. Recommended
setting for cache_mem is at most 16MB unless you have plenty of ram.

Remeber that Squids memory usage will grow as the on-disk cache grows.
You can't determine the memory requirements from an empty Squid. See the
FAQ for details.

> For instance, I'm making an assumption that squid doesn't load up that
> space until its full before it starts to dump stuff to disk...that it
> times out the data after a period of inactivity of that 'object'...so
> that, with enough RAM, I could theoretically keep that 'memory cache'
> below 100% utilization ...

On some objects Squid save an shadow copy in ram when the object is sent
to disk, also negatively cached replies are only stored in ram.

> So, anything similar to the dnsserver stats that just gives a simple
> summary/percentage used?

The amount of cache_mem used is shown in "Memory Utilization" as "Store
Mem Buffer". This includes both full objects and in-transit data.

There is no "memory hit rate" calculated in Squid, so you need to
calcualte this from your access log.

--
Henrik Nordstrom
Spare time Squid hacker