In my opinion, the problem of having separate caching based on URL is that in case of problems, secondary failover server has a empty cache for rest of URL, so can affect to throughtput.
Our architecture is the following: [1. F5 LB] => [2. Varnish] => [3. Tomcat] 1) F5 Big IP Hardware Load Balancer 2) Four Varnish cache in diferent machines 3) Four Tomcat servers in diferent machines We don't care to have redundant caching because: - we don't have resource problems - in case of problems, all varnish instances has the cache already populated 2011/1/28 Gresens, August: > 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 > _______________________________________________ varnish-misc mailing list [email protected] http://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
