I thought the commonly accepted way to do this was to * Have more than one application server * Deploy new code to a non-active application server * Send som

I thought the commonly accepted way to do this was to * Have more than one application server * Deploy new code to a non-active application server * Send some traffic to the new app server (perhaps based on cookie) * When confident, switch traffic (using Varnish/other load balancer) to the new application server