We have two varnish servers behind the load balancer (nginx). Each varnish server has an identical configuration and load balances the actual backends (web servers).
Traffic for particular url patterns are routed to one of the varnish servers by the load balancer. For each url pattern the secondary source is the alternate varnish server. In this way we can we partition traffic between the two varnish servers and avoid redundant caching but the second one will act as a failover if the primary goes down. Best, A -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Angelo Höngens Sent: Friday, January 28, 2011 8:42 AM To: [email protected] Subject: Re: How to set up varnish not be a single point of failure On 28-1-2011 14:38, Caunter, Stefan wrote: > > > > On 2011-01-28, at 6:26 AM, "Stewart Robinson" <[email protected]> wrote: > >> Other people have configured two Varnish servers to be backends for >> each other. When you see the other Varnish cache as your remote IP you >> then point the request to the real backend. This duplicates your cache >> items in each cache. >> >> Be aware of http://www.varnish-cache.org/trac/wiki/VCLExampleHashIgnoreBusy >> >> Stew >> >> On 28 January 2011 10:46, Siju George <[email protected]> wrote: >>> Hi, >>> >>> I understand that varnish does not support cache peering like Squid. >>> My planned set up is something like >>> >>> >>> ---- Webserver1 --- ------- Cache --- >>> ------ API >>> LB ----| |---- LB----| |---- LB >>> ----| >>> ---- Webserver2 --- ------- Cache --- >>> ------ API >>> >>> So if I am using Varnish as Cache what is the best way to configure them so >>> that there is redundancy and the setup can continue even if one Cache fails? >>> >>> Thanks >>> >>> --Siju > > > Put two behind LB. Caches are cooler but you get high availability. > Easy to do maintenance this way. We use Varnish on CentOS machines. We use Pacemaker for high-availability (multiple virtual ip's) and DNSRR for balancing end-users to the caches. see http://blog.hongens.nl/guides/setting-up-a-pacemaker-cluster-on-centosrhel/ for the pacemaker part.. -- With kind regards, Angelo Höngens systems administrator MCSE on Windows 2003 MCSE on Windows 2000 MS Small Business Specialist ------------------------------------------ NetMatch tourism internet software solutions Ringbaan Oost 2b 5013 CA Tilburg +31 (0)13 5811088 +31 (0)13 5821239 [email protected] www.netmatch.nl ------------------------------------------ _______________________________________________ varnish-misc mailing list [email protected] http://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc SCHOLASTIC Read Every Day. Lead a Better Life. _______________________________________________ varnish-misc mailing list [email protected] http://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
