Re: [squid-users] ICP is not working as expected

[Amos Jeffries]

Atef Alqashqish wrote:

Thank you

Would you please share with you a configuration example for two squid servers 
running behind hardware NLB switch where they use ICP and sibling relation, one 
of the two server is the origin for both

The sibling part of the config you had sort of right.
It was the accelerator part which was screwing it up.
The correct config for a reverse proxy (aka accelerator) is detailed at
http://wiki.squid-cache.org/SquidFaq/ReverseProxy

Amos

Regards

Atef A. M. AlQashqish
Operation Manager / MCSE, MCT, ITIL Certified Service Manager


-----Original Message-----

From: Amos Jeffries [mailto:squ...@treenet.co.nz] Sent: Sunday, January 18, 2009 1:34 PM

To: Atef Alqashqish
Cc: squid-users@squid-cache.org
Subject: Re: [squid-users] ICP is not working as expected

Atef Alqashqish wrote:

Hi,

I have two servers Windows 2003 with SQUID 2.7 stable 3, one of them act as 
origin for the two squid instances, hence one squid installation co-exist on 
the same box with IIS application and web site, the two squid works as expected 
as long as ICP and cache hierarchy is not used, only one cache_peer as parent 
and origin.

To enhance the site performance we decide to use ICP and make one server use 
the second server squid as its sibling with proxy-only option, we always get 
ICP_MISS in the cache log even though we are sure the URL is cached in  the 
first SQUID cache!, the below are the configuration:

First off 'proxy-only' is probably not a good choice in these circumstances. It prevents any sibling fetched objects being cached, yet you are caching objects direct from the parent. You _want_ the fastest possible response in an accelerator, which means caching.

Secondly you are not doing a clear accelerator. For your cofiguration below to work, something funky has to be going one with either DNS or URL re-writers which breaks any possibility of siblingship.

See below for a description of the problem.

See http://wiki.squid-cache.org/SquidFaq/ReverseProxy#head-7fa129a6528d9a5c914f8dd5671668173e39e341

  for a demo config of how accelerators should be configured.

Server1 (Origin with IIS site and SQUID cache), IP 10.10.0.191:
cache_peer 10.11.0.197 parent 80 0 no-query originserver
acl usasite dstdomain 10.10.0.191

You sure clients are really asking for "http://10.10.0.191/"; ??

cache_peer_access 10.11.0.197 allow usasite
cache_peer_access 10.11.0.197 deny all
http_access allow usasite

icp_port 3130
icp_access allow all

Server2(IP 10.10.10.16):
http_port 10.10.10.16:80 accel defaultsite=10.10.10.16

So your domain name is not "10.10.0.191" but "10.10.10.16" now?

cache_peer 10.10.0.191 sibling 80 3130 proxy-only cache_peer 10.11.0.197 parent 80 0 no-query originserver

acl usasite dstdomain 10.10.10.16

Must be, but the sibling Server1 doesn't know or accept the domain name when asked for "http://10.10.10.16/";

cache_peer_access 10.11.0.197 allow usasite
cache_peer_access 10.11.0.197 deny all
cache_peer_access 10.10.0.191 allow usasite
cache_peer_access 10.10.0.191 deny all
http_access allow usasite

icp_port 3130
icp_access allow all

Please help

Atef A. M. AlQashqish
Operation Manager / MCSE, MCT, ITIL Certified Service Manager

iHorizons Tel : - +962 6 534 1640 ext 61

Mobile:-     +962 777 530053
Fax:-         +962 6 534 1927
P.O. BOX 1610 Jubaiha 11941 Amman - Jordan

http://www.iHorizons.com

Amos

--
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