How to organize internal communication of microservices with each other?

Question

Node.js

If I want to make my service as atomic as possible, consisting of many small services, and not make some of these services public, but leave them for debugging and internal inter-service communication. How to properly organize the internal communication of microservices?
In particular, if the service is made on Node.JS & Express, then how to organize the communication of components with each other so as not to load the HTTP server and how to close some routes for external users?

Answer 1

Organize a data bus based on, for example , zeromq (it is often used in the context of microservices). There is even something ready , as an example.

Answer 2

When we switched to microservices, we also faced a similar problem. And they wrote their own library. Works faster than through zeromq. there is no intermediary, only a direct socket connection.
You can get the server part here https://www.npmjs.com/package/aud-socket-server and the client part here https://www.npmjs.com/package/aud-socket-client