Re: [squid-users] TCP_HIT and TCP_MISS

Guillaume Chartrand wrote:
>> -----Message d'origine-----
>> De : ferret@gci.net [mailto:ferret@gci.net] De la part de Chris Robertson
>> Envoyé : 20 mars 2008 21:21
>> À : squid-users@squid-cache.org
>> Objet : Re: [squid-users] TCP_HIT and TCP_MISS
>>
>> Guillaume Chartrand wrote:
>>
>>> I try the solution on the other post to increase file descriptor
>>> I have 4096 when I do a ulimit -n
>>> I recompile squid
>>> Here what I have when I run squid -v
>>> Squid Cache: Version 2.6.STABLE12
>>> configure options:
>>>
>>>
>> No configure options at all? The default (last I checked) did not allow
>> for support of aufs cache dirs.
>>
>
>
> I've just run ./configure
> Without no other option. Now I look for enable aufs cache dir but I didn't find with option I need to enable. The only option who's near that it's
> --with-aufs-threads=N_THREADS
>
> If it's that option, how many threads should I put.
>
>

Personally I use "--enable-storeio=aufs,null,ufs", with a few other
options (with-large-files, enable-snmp,
enable-removal-policies=heap,lru). There is a message in the archives
(somewhere, I can't find it right now) where Henrik explains that ufs is
actually better for a lightly loaded cache (less overhead), but the
blocking becomes a factor as the requests per second rise. For me it
has become reflexive to suggest using aufs.

>>> 2008/03/18 09:11:01| NOTICE: no explicit transparent proxy support enabled. Assuming getsockname() works on >>intercepted conne
>>> ctions
>>> 2008/03/18 09:11:01| WARNING: Forwarding loop detected for:
>>> Client: 172.20.20.18 http_port: 172.20.20.18:3128
>>> GET http://172.20.20.18:3128/design/motherbd/software/ias/updates.htm HTTP/1.0
>>> Via: 1.0 squid.collanaud.qc.ca:3128 (squid/2.6.STABLE12)
>>> X-Forwarded-For: 172.21.132.93
>>> Host: 172.20.20.18:3128
>>> Cache-Control: max-age=259200
>>> Connection: keep-alive
>>>
>>>
>>>
>
>
>> So your router is intercepting Squid's traffic and redirecting it back
>> to Squid. That's not so good. In a big way.
>>

This was not addressed in your reply. Hopefully it was addressed on
your network. I feel it's the real issue.

>>> And here is some of my squid.conf
>>> # Squid normally listens to port 3128
>>> #http_port 3128
>>> http_port 3128 transparent
>>> #Default:
>>> # cache_mem 8 MB
>>> cache_mem 512 MB
>>> #Default:
>>> # maximum_object_size 4096 KB
>>> maximum_object_size 25600 KB#Default:
>>> cache_dir ufs /usr/local/squid/var/cache 2500 16 256 # this one is a symlink to another disk
>>>
>>>
>
>
>> A symlink, or is the other disk mounted here. No matter, but you should
>> probably be using aufs, which you will have to compile support for.
>>
>
> It's a symlink only.
>

Interesting. Any reason for using a symlink instead of a mount point?

>
>>> cache_dir ufs /usr/local/squid/var/cache2 2500 16 256
>>>
>>>
>
>
>> So how much memory does this box have? You've dedicated about a GB of
>> RAM for Squid alone (512 cache_mem + (5GB of cache_dir * 0.1)).
>>
>
> The machine is on VMware virtual machine and have 2 disk of 40GB each and 1GB of RAM
>

Ugh. My calculation was off by an order of magnitude. 5GB of cache
will only take (on average) 50MB of memory. See
http://wiki.squid-cache.org/SquidFaq/SquidMemory for more details. But
be aware, squid does not put objects from the disk cache BACK into
memory. Only objects fetched from the net are put in the memory cache.

>
>>> all the other option is default value and I have some config for wccp
>>>
>>>
>
>
>> And apparently some url_rewriters (unless those are implied by using
>> wccp...).
>>
> Yes I have SquidGuard configured with squid
>
>
>> Chris
>>
>
> Thank
> Guillaume
>
Received on Tue Mar 25 2008 - 13:42:08 MDT