Neat. Interestingly, for all its faults PHP in my experience has made this a little easier to achieve than other languages we also use: shared-nothing and no internal process state between requests makes cutting over a bit easier than our equivalent node servers. Some great practical advice in this article.
That's a flaw in how you use node, not node itself. We run dozens of instances of node without internal process state, the need for sticky sessions, etc. You're losing a lot of load-balancing ability by not keeping this discipline too.
