[squid-users] Performance tips for accelerator setup

Hi folks,

we're using Squid in an accelerator setup for some time now and it ran
very smoothly. But now we're getting into some performance trouble. But
before buying new iron I want to try to squeeze some more performance
out of our current setup. So if you have any hints on doing this please
share them.

Here the facts:

- Version: 2.7.STABLE7-2
- triple sibling peers with two parents
- using acl urlpath_regex since data are partially different on parents
- max Traffic: 30 MBit/s Outgoing - 8 MBit/s ingoing
- max 800 req/s
- 2x Xeon Dualcore 2 GHz
- 4x 146 GB disks
- max CPU Usage:
  Total: 24%
  Wait: 16%
  User: 6%
  System: 2%

Configuration:
I post only the important parts(hopefully...)

cache_peer server1 parent 80 0 no-query no-digest originserver
round-robin name=s1
cache_peer server2 parent 80 0 no-query no-digest originserver
round-robin name=s2
# Siblings exchange cache digest
cache_peer image10 sibling 80 0 proxy-only name=img10
cache_peer image45 sibling 80 0 proxy-only name=img45
# we have 16GB and use 8 as cache
cache_mem 8192 MB
# Mean Object Size is ca. 28 KB so we use 50 KB
maximum_object_size_in_memory 51200 bytes
memory_replacement_policy lru
cache_replacement_policy lru
store_dir_select_algorithm least-load
collapsed_forwarding on
# since our content changes very fast we rebuild the digest every ten
minutes
digest_rebuild_period 10 minutes
digest_rewrite_period 10 minutes
# ca. 80 GB per Disk on Reiser-FS
cache_dir aufs /web/cache/1 81920 290 256
cache_dir aufs /web/cache/2 81920 290 256
cache_dir aufs /web/cache/3 81920 290 256
cache_dir aufs /web/cache/4 81920 290 256

Since we cache only tons of small pictures I was thinking about
implementing COSS. But it's hard to find useful information about it. So
if this is a real alternative here, can you please point me to some
documents which help with implementing this. I know about [1] but I
don't know if this is still valid for 2.7 and it's not easy to wrap my
head around it.

[1] http://wiki.squid-cache.org/Features/CyclicObjectStorageSystem

Cheers, Markus
Received on Fri Jan 15 2010 - 12:18:58 MST