Re: [squid-users] Memory usage...

From: Amos Jeffries <squid3_at_treenet.co.nz>
> Actual experienced measurements from some general-purpose web caches. On 32-bit
> systems. Newer 64-bit systems have reported a 15MB/GB requirement.
> It's the amount of data seen to be used for index meta data and other types of
> index.
> ...
> The average average size of web traffic items here is around 64KB.
> ...
> Assuming what sized object?
> An (empty) web HTML 0.9 page has as few as 14 bytes. XML files likewise may only
> have 20 bytes or so.
> For a cache full of those (think dynamic web app gone downright evil), you would
> need about 1MB memory per MB of cache.
> Whereas at the other end, if you are caching only ISO DVD images. Your memory
> drops to under 1KB memory per GB of cache.
> Its a 'rule-of-thumb', which means we recommend to newbies that they use it to
> plan and configure their system memory. And over time watch their squid to see
> how it needs adjusting for best performance.

Hi,

replying to an old post...
We finaly bought our squid servers (540GB of disk, 48GB of RAM)... and I am a bit scared...
I know it is just a rule of thumb but, if I re-apply the formula (for 64KB average object sizes) and, having 16KB average object sizes, multiply the required RAM by 4 (64/16), I get...

  -------------------------+----------------+-------------
    cache_dir (best) | RAM for DISK | cache_mem
  -------------------------+----------------+-------------
       613 GB ( 306 GB) | 36 GB | 1 GB
       544 GB ( 272 GB) | 32 GB | 6 GB
       476 GB ( 238 GB) | 28 GB | 11 GB
       408 GB ( 204 GB) | 24 GB | 16 GB
       340 GB ( 170 GB) | 20 GB | 21 GB
       271 GB ( 135 GB) | 16 GB | 26 GB
       203 GB ( 101 GB) | 12 GB | 31 GB
       135 GB ( 67 GB) | 8 GB | 36 GB
        66 GB ( 33 GB) | 4 GB | 41 GB
  -------------------------+----------------+-------------

do these values look mostly correct?

Thx,
JD

      
Received on Fri Mar 05 2010 - 15:14:32 MST