joyent/node — comment on commit 1e3e6b7c15f39500d30d91846ad3621fb72aa91b
File:  line 0
By bnoordhuis:

@shtylman: You can have two masters listening on different ports, each with its own set of workers. Not sure what you mean by 'bounce'. If you stop forwarding requests to one of the masters, eventually it'll have processed all outstanding requests and then you can safely upgrade it. I don't see how that is different from a non-clustered solution.