On Thu, Jan 26, 2012 at 12:53 AM, Jason T. Slack-Moehrle < slackmoehrle at gmail.com> wrote: > HAProxy is a load-balancer, so It should do in front of web-servers so it > can decide which web-server to send the traffic to? > > Varnish Cache is all about caching commonly used resources so it seems > that this has to go in front too? > > Can this be the same box realistically? How does one spec this box out? > Varnish will do the load-balancing for you as well. What you need to figure out is the failover scenario fron one varnish to another - IF you really need more than 99.9 percent uptime. A varnish machine should have LOTS of memory and a fair bit of fast disk with a BIG swapfile on it. Basically varnish treats the entire virtual memory space as its cache storage and let's vfs worry about what should be in memory and what can be swapped out. BR Bent