For this, Node.js is supposed to run several processes. While one is tied up, another one works. This is almost as good as erlang actor model. You can have a small scheduler library figuring out who to send the next request to.

What I do think is that Node.js processes should be expected to crash at any time. Because a Node.js process serves many requests, it can run out of memory, or anything else. Node.js processes should be able to be restarted instantly, with the consequence of only a few dropped requests (in fact, the requests should be retried if they fail due to a crash, before reporting a failure to the client).