node.js – NodeJS cluster, useful use cases?

I'm researching use cases to introduce cluster computing with nodejs to a few friends.

My goal is to explain some real cases of nodejs clusters, and why knotjs is helpful in creating these special cases.

So far, I really like a single case:

  • Clustering a web server (like an API server to REST) (Reason: load distribution)

I have seen examples of expensive computation and the advantages that arise on a different thread / processor.

This has led me to think about whether there are work pools where each pool performs different parts, e.g. For example, connecting to a database, generating PDFs, and the like.

While trying to understand the connections between the worker and the master, I played around and am still unsure:

  • nodejs clusters are only suitable for running the same process in parallel (documentation suggests)
  • or does it make sense to have node cluster clusters as separate tasks in pools.

.. which leads to the following results: Which use cases are actually real with nodejs?

I hope it is understandable.
Opinions are very welcomed.