Re: [squid-users] Can a cache be "too big"?

On Wed, Jul 21, 2010 at 4:57 PM, Marcus Kool
<marcus.kool_at_urlfilterdb.com> wrote:
> yes.
> 1) the index is in memory and needs 10-20 MB index in memory for each GB on disk

I was under the impression (from the oriely squid manual) that recent
versions do not use up extra RAM with bigger caches.
But maybe I read it wrong?
Also, I'm a bit confused as there's only one apparent "memory" option
in the squid configuration.

Could you explain/point me to a tutorial?

> 2) the housekeeping of the index costs more CPU cycles for a larger cache
> 3) the housekeeping of the cached objects on disk costs time and grows when the cache is larger.  Can be minimised by having cache_swap_low 92 and cache_swap_high 93.
>
> The system has 2 GB memory, assuming that the system is dedicated for Squid
> you need 400 MB for the OS, leaving 1.6 GB for Squid.
> A safe value for cache_mem would be 500 MB
>
> There are many tuning parameters.
> The best one is to have more disks.
>
> Marcus
>
> Marcello Romani wrote:
>>
>> Ralf Hildebrandt ha scritto:
>>>
>>> * Ralf Hildebrandt <Ralf.Hildebrandt_at_charite.de>:
>>>
>>>> maximum_object_size 50 MB
>>>> cache_dir diskd /squid-cache 45000 16 16
>>>> request_header_max_size 15 KB
>>>> request_body_max_size 750 MB
>>>>
>>>> The machine is 32 bits, MemTotal:        2060960 kB
>>>
>>> Some stats from before "the purge":
>>>
>>> 1.4Mio cached objects
>>> 42GB Cache size
>>>
>>
>> Could it be that cache_mem + memory required to manage 42GB of cache caused the squid process to be swapped ?
>>
>
Received on Wed Jul 28 2010 - 08:13:54 MDT