Re: [squid-users] Squid-cache clustering

Hello,

I am a bit confused here. I am currently running an several servers each
with an instance of apache 2 and squid 2.5 using:

httpd_accel_single_host On
httpd_accel_host 127.0.0.1
httpd_accel_port 80

>From your email it seems like I can set the apache servers as cache
peers? Is that correct.

I ask because I would like to put squid on separate servers but can't
figure out a very good mechanism for it it to use all the "origin"
servers and detect if an origin server is down.

Jerry

On Fri, 2006-04-07 at 23:45 +0200, Henrik Nordstrom wrote:
> fre 2006-04-07 klockan 09:53 -0700 skrev Ben Drees:
> > I am curious about a related question:
> >
> > In reverse proxy scenarios, what are the options for load balancing
> > cache misses among several origin server replicas?
>
>
> I would make each origin a peer to Squid, allowing Squid to use
> round-robin etc for balancing the load.. Just remember to set the
> connect timeout fairly short for better failover performance.
>
> > 2) It is my understanding that if DNS returns more than one address for
> > a hostname, Squid can be configured to perform round-robin selection of
> > an origin server. Are there any caveats to be aware of when persistent
> > connections are used between squid and the origin servers?
>
> Yes, and it does by default. The problem is if/when there is a problem
> with one server, it may then become very hard to make Squid use that
> server again..
>
> > 3) It seems like the Redirector API could be used as a hook to do this
> > kind of load balancing also, offering a convenient place to code custom
> > health checks.
>
> I would avoid this if possible. Redirectors is quite resource demanding,
> and it's tricky to get the setup correct when rewriting the URLs while
> proxied... (cache gets split, backends may get confused about the actual
> requested domain etc..)
>
> Regards
> Henrik
>
>

-- 
Jerry Thomas            thomasj@scoregroup.com
I.T. Director           ph. 305-662-5959 ext. 242
The SCORE Group         fax 305-662-8922