Re: [squid-users] coss storage scheme.

From: Chris Woodfield <rekoil_at_semihuman.com>
Date: Thu, 7 Jan 2010 10:21:42 -0800

One thing we've noticed is that until the COSS store is rebuilt, no objects get saved to it (each attempt shows up as SO_FAIL in cache.log). Complicating this further is the fact that -F doesn't seem to work for COSS rebuilds - I know I opened a bug on this but I can't seem to find it at the moment...

-C

On Jan 6, 2010, at 5:18 PM, Manjusha Maddala wrote:

>
> On a related note,
>
> if Squid is configured to use AUFS and COSS for its cache_dirs, does it
> store the "Vary Internal Marker Objects" only in the COSS file or
> somewhere else too? For my setup, I notice the marker objects which
> provide "vary" meta-data for all the cached pages are stored in COSS.
>
> If there is a COSS cache_dir, Squid attempts to store all the cached
> objects less than the max_size for COSS object in the COSS file. As a
> result, some of the "Internal Marker Objects" get evicted out (during
> COSS recycle) thereby resulting in low cache hit ratio for my setup.
>
>
>
> On Wed, 2010-01-06 at 16:58 -0800, Chris Robertson wrote:
>> Jeronimo Garcia wrote:
>>> Hi all.
>>>
>>> I've been looking at a bunch of benchmarks about storage schemes for
>>> squid and coss looks
>>> rather impressive , but , reading squid the definitive guide i got to
>>> know that the code might be a bit beta/unstable.
>>>
>>
>> http://wiki.squid-cache.org/Features/CyclicObjectStorageSystem
>>
>>> Now i didn't really check when this book was written but I've been
>>> coming across with it for a bunch of years already so i imagine is not
>>> very new.
>>>
>>> Does some of you have some real experiences with coss?
>>
>> Squid 2.7STABLE6
>>
>> My COSS dirs are about 45 GB each on bare partitions (cache_dir coss
>> /dev/sdc1 46080 max-size=51200 max-stripe-waste=32768 block-size=4096).
>> Each server passes about 100 GB of traffic per day (to my customers,
>> ~25% from cache), with a peak requests/second of around 150. No issues
>> with stability (currently I have over 50 days of uptime).
>>
>>> I'm also very
>>> interested on squid's start-up time when using coss.
>>>
>>
>> Squid starts up just fine but thrashes the disks hard for about half an
>> hour while it reads the COSS dirs to build the index. There is no
>> noticeable effect on performance.
>>
>>> Many Thanks
>>> -J
>>>
>>
>> Chris
>>
Received on Thu Jan 07 2010 - 18:21:53 MST

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