It's maybe possible to do it in VMOD, if you're not scared by developing in C.
You need to recreate the round-robin behavior by implementing yourself this
feature.. and then let the VMOD selecting the right backend for you.
Jonathan Huot
Phone: +33(0)1.47.62.78.65
From: varnish-misc-bounces+jonathan.huot=thomsonreuters....@varnish-cache.org
[mailto:varnish-misc-bounces+jonathan.huot=thomsonreuters....@varnish-cache.org]
On Behalf Of Tharanga Abeyseela
Sent: Friday, 30 August 2013 02:56 PM
To: MAGNIEN, Thierry
Cc: Varnish misc
Subject: Re: Varnish round-robin loadbalancing with Virtualhost (Namebased)
That is my requirement !!!. i'm using the same IP address for both hosts, and
need to do the load-balancing between two servers. thats what i wanted to know,
Actually i'm playing with different varnish configs :) on my virtual box.,
thought to give this config a try....but that didnt work. it is working
perfectly with different IP's, or IP based Vhosts.
Thanks Thierry for the response.
cheers,
Tharanga
On Fri, Aug 30, 2013 at 10:46 PM, MAGNIEN, Thierry
<[email protected]<mailto:[email protected]>> wrote:
Hi,
I think I understood the point :
- you have 2 backends hosted under the same IP address :
www.backend1.com<http://www.backend1.com> and
www.backend2.com<http://www.backend2.com>
- your varnish server gets requests (for example) for
www.frontend.com<http://www.frontend.com>
- you want requests to be load-balanced between your 2 backends BUT this would
need the bereq.host to be rewritten to either
www.backend1.com<http://www.backend1.com> or
www.backend2.com<http://www.backend2.com>
- BUT you can't do this in your VCL because you don't know which backend will
be selected.
In fact, this would need the director to rewrite the host header once the real
backend has been selected, which I don't think is possible.
Anyway, I still wonder why the hell you need varnish for this, where a HAProxy
would certainly do the trick ;-)
Regards,
Thierry
De :
[email protected]<mailto:[email protected]>
[mailto:varnish-misc-bounces+thierry.magnien<mailto:varnish-misc-bounces%2Bthierry.magnien>[email protected]<mailto:[email protected]>]
De la part de Per Buer
Envoyé : vendredi 30 août 2013 13:36
À : Tharanga Abeyseela
Cc : Varnish misc
Objet : Re: Varnish round-robin loadbalancing with Virtualhost (Namebased)
Hi Tharanga,
You seem not to understand. Varnish will just pass the host header in the
request to the backend you specify. Looking at the VCL you provided you put
both the backends into one director. This is probably not what you want to do.
Try removing the director. Name the directors xxx and yyy and have the VCL look
like.
sub vcl_recv {
if (req.http.host ~ "xxx.com<http://xxx.com>") {
req.backend = xxx;
} else if (..
}
Also the next bit doesn't make sense:
if (req.request)
{
return(pass);
}
}
On Fri, Aug 30, 2013 at 10:42 AM, Tharanga Abeyseela
<[email protected]<mailto:[email protected]>> wrote:
Hi,
Actually i tried that link, still it is not working. it should work for a ip
based virtual host, but namebased virtual host is not working.
becuase main request coming to varnish/80 and varnish should redirect the
traffic to the backend server based on my round-robin director. when you
resolve dns for those two hosts (xxx.com<http://xxx.com> and
yyy.com<http://yyy.com>) it reuturns the same IP. that is 192.168.0.100. But
there should be a way to send the host-header to apache. Not sure how it works
here. But when i use different server (192,168.0.200/ zzz.com<http://zzz.com>)
it works without any issue, it roundrobin the traffic. This is an issue with
namebased virtualhost.
varnish recevie the traffic (cluster.com<http://cluster.com> is my varnish
server), then it use it vcl to redirect based on my round-robin setting. but
how it can send the traffic to the correct virtualhost. because it gets only
the same IP address from the DNS. I managed to change the default behaviour by
forcefully setting the host-header as follows to my other virtualhost(yyy..com)
set.req.host="yyy.com<http://yyy.com>" ;
then all request went to yyy.com<http://yyy.com> instead of
xxx.com<http://xxx.com>. but what i want is a round-robin fashio...to send
traffic. first req to xxx.com/<http://xxx.com/> 2nd req to
yyy.com<http://yyy.com> and so on..
I was trying to find some resourses on the net, stackoverflow etc..but no luck
yet.
Thanks again for your help
Cheers,
Tharanga
On Fri, Aug 30, 2013 at 5:05 PM, Per Buer
<[email protected]<mailto:[email protected]>> wrote:
Hi Tharanga,
You seem to be a bit confused about how the directors and backends work in
Varnish. Please read this:
https://www.varnish-cache.org/docs/trunk/users-guide/vcl-backends.html#backends-and-virtual-hosts-in-varnish
Note that the .host property of the backend has NOTHING to do with the virtual
host.
On Fri, Aug 30, 2013 at 2:02 AM, Tharanga Abeyseela
<[email protected]<mailto:[email protected]>> wrote:
Hi Per,
Thanks for the reply. Actually my set up looks like this.
cluster.com<http://cluster.com> - 192.168.0.200 (varnish/port 80)
xxx.com<http://xxx.com> - 192.168.0.100 (apache,namebased vhost/8080 -
backendname - website)
yyy.com<http://yyy.com> - 192.168.0.100 (apache,namebased vhost/8080
-backendname - api)
cluster.com<http://cluster.com> is the varnish server and front-end connections
coming to this and rewrite to other defined back-ends (round-robin based
balancing)
backend website {
.host = "xxx.com<http://xxx.com>";
.port = "8080";
}
backend api {
.host = "yyy.com<http://yyy.com>";
.port = "8080";
}
director clust round-robin {
{ .backend = api; }
{ .backend = website; }
}
sub vcl_recv {
set req.backend = clust;
if (req.request)
{
return(pass);
}
}
when i hit the cluster.com<http://cluster.com> , it is always going to
xxx.com<http://xxx.com>, but what i need to do is first request go to
xxx.com<http://xxx.com> second request yyy.com<http://yyy.com> and so on...when
i add another server (different host/different IP say
192.168.0.111/zzz.com<http://192.168.0.111/zzz.com>, and a different backend) ,
it goes like this
first request - xxx.com<http://xxx.com>
second request - xxxx.com<http://xxxx.com>
third request - zzz.com<http://zzz.com>
but i can change the default behavior by setting up set req.host =
yyy.com<http://yyy.com> and then it will goes to
first request - yyy.com<http://yyy.com>
second request - yyy.com<http://yyy.com>
third request - zzz.com<http://zzz.com>
this is something to do with the host-header forwarding to the correct
back-end. how should i add that functionality to the vcl_recv ?
appreciate your help on this, this is working perfectly with other servers
(different servers, not with namebased vhosts)
cheers,
Tharanga
On Thu, Aug 29, 2013 at 11:58 PM, Per Buer
<[email protected]<mailto:[email protected]>> wrote:
Hi mate,
On Thu, Aug 29, 2013 at 3:17 PM, Tharanga Abeyseela
<[email protected]<mailto:[email protected]>> wrote:
(..)
But how should i send host-headers to varnish to redirect to the correct
server, This is always going to xxx.com<http://xxx.com>.
You don't. :-)
You need to dispatch the request to the right backend in vcl_recv and have the
backend handle that host. You could start rewriting the host in vcl_recv, but I
would advise against it.
So, if you have two vhosts handled by "website" you just set that as the
backend in vcl_recv.
--
Per Buer
CTO | Varnish Software AS
Phone: +47 958 39 117<tel:%2B47%20958%2039%20117> | Skype: per.buer
We Make Websites Fly!
Winner of the Red Herring Top 100 Europe Award 2013
--
Per Buer
CTO | Varnish Software AS
Phone: +47 958 39 117<tel:%2B47%20958%2039%20117> | Skype: per.buer
We Make Websites Fly!
Winner of the Red Herring Top 100 Europe Award 2013
--
Per Buer
CTO | Varnish Software AS
Phone: +47 958 39 117<tel:%2B47%20958%2039%20117> | Skype: per.buer
We Make Websites Fly!
Winner of the Red Herring Top 100 Europe Award 2013
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