Will running nREPL on a Clojure application in a production environment result in a noticeable performance impact?
I anticipate that my application might encounter an issue that requires debugging or fixing using nREPL, but I'm concerned about the potential performance impact of using nREPL.
By itself the nREPL won't have much, if any, impact. But what you do in that REPL certainly can, so use caution. And be sure to secure the port! Or set it up to use a unix domain socket if that's applicable.
There will be some sort of performance change just given the fixed resources, but I would guess it will be pretty negligible.
I seem to remember implementing a feature in a service one time that would let me turn on an nrepl server via a route if I needed it and then turn off when I was done.
Do be careful with a repl in a live server. With great power....