On Tue, 18 Jan 2011, Rhys Rhaven wrote:
Having hit these issues myself, I heavily recommend a real frontend proxy like nginx or varnish.
A frontend proxy (nginx, varnish, haproxy, or anything else) doesnt give you HA any more than any other loadbalancer solution does. You need a way to send traffic to another frontend server when the primary frontend server fails, or is overloaded, transparently. The tools we have available these days to do this are VRRP-like solutions (which all of the appliances use) that use multicast, some amount of NAT and routing magic (which I've often not seen done sanely), or DNS solutions (better known as GSLB) that dynamicly change the DNS responses depending on conditions (which could be source location, or could be server availability, or whatever). Normally, VRRP would be the way to go. But these days multicast isn't supported everywhere (major example - Amazon EC2), leaving DNS... -- david raistrick http://www.netmeister.org/news/learn2quote.html drais@icantclick.org http://www.expita.com/nomime.html