I'm new to javascript, Node.js, and 0MQ, so n00b * 3 here.
I want to set up a simple request and reply, but I want the client to wait for a response before sending out the next request.
The zguide goes over this, but the Node.js version does not behave like the C version (which is what I want).
I realize I'm butting up against a paradigm shift here in how I look at the problem, but I still feel like I should be able to do this. Can I make a recv call (or something similar) in the client?
You're right, the node.js version of ZMQ doesn't behave the way you would expect it to if you're coming from the C version, but it actually is behaving according to the rules, it's just adding in a bit of its own sauce to the mix.
Specifically, the C bindings will throw an error if you try to break the strict REQ/REP/REQ/REP cycle. In node.js, it will cache the out-of-order message until the previous response comes back, and then send out that new message... so you're still getting REQ/REP/REQ/REP, in order, and you can choose to send a message whenever you want without an error.
This is probably a poor design choice on the part of the node ZMQ binding authors, first of all because it's confusing to new users such as yourself, and second of all if you're using REQ/REP you'd probably prefer a hard failure if you go out of order, otherwise you'd be using a different socket type.