Hi Usman,
usman wrote:
Hi EveryOne,
I am getting very low Request Hit ratio on squid cache since i
implemented coss. The caching directories containing coss stripes file
are filling up very very slow.
/dev/amrd1s1d 16G 136M 15G 1% /cache1
/dev/amrd2s1d 16G 141M 15G 1% /cache2
/dev/amrd3s1d 33G 5.9G 24G 20% /cache3
From what I understand, COSS by default stores smaller objects in
comparison to UFS, AUFS or DISKD.
This may explain why the COSS directories are filling up slowly.
you can see the comparison between diskd and coss directories.
The cache_dir settings are
cache_dir coss /cache1 12000 max-size=1048576 max-stripe-waste=524288
membufs=500
cache_dir coss /cache2 12000 max-size=1048576 max-stripe-waste=524288
membufs=500
cache_dir diskd /cache3 28000 16 256 Q1=72 Q2=64
My COSS cache_dir are as follows:
cache_dir coss /cache1/squid/coss 8192 max-size=131072
max-stripe-waste=16384 block-size=1024 membufs=500
On other caches with same refresh pattern (total Diskd or Aufs) I get
around 45 - 55 % Request HIT ratio. Currently its 12 % with coss. The
caching directories are not fully loaded yet but still I feel its very
low request hit ratio.
In one of my FreeBSD Squid box utilizing COSS with the following uptime:
Squid Object Cache: Version 2.6.STABLE16
Start Time: Sun, 09 Sep 2007 11:31:49 GMT
Current Time: Thu, 25 Oct 2007 16:33:23 GMT
I get the following results:
Request Hit Ratios: 5min: 47.3%, 60min: 46.1%
Byte Hit Ratios: 5min: 17.9%, 60min: 17.5%
Request Memory Hit Ratios: 5min: 0.2%, 60min: 0.3%
Request Disk Hit Ratios: 5min: 55.2%, 60min: 54.5%
Cache Hits: 0.00767 0.00767
Near Hits: 1.38447 1.31166
Where is something wrong in my Config ?
I am sure that the low HIT ratio is not a Configuration problem.
Also please suggest the size of "block-size" in coss settings, I am
using FreeBSD 6.2 with UFS2 file system (with default block size of file
system 16384 bytes).
RAM is 4 GB, SMP System.
How long has your FreeBSD squid box been running? My advise is to be a
little more patience with COSS. Let the COSS directories get filled up.
I am sure that your request HIT ratios will gradually increase.
Regards
usman
Thanking you...
--
With best regards and good wishes,
Yours sincerely,
Tek Bahadur Limbu
System Administrator
(TAG/TDG Group)
Jwl Systems Department
Worldlink Communications Pvt. Ltd.
Jawalakhel, Nepal
http://www.wlink.com.np
http://teklimbu.wordpress.com
