I’m learning about node.js clustering from a course where we have the following setup.

process.env.UV_THREADPOOL_SIZE = 1;
const cluster = require("cluster");

if (cluster.isMaster) {
  cluster.fork();
  cluster.fork();
} else {
  const express = require("express");
  const crypto = require("crypto");
  const app = express();


  app.get("/", (req, res) => {

    setTimeout(() => {
      res.send("Hi There!");
    }, 5000);

    console.log(`Request handled by ${process.pid}`);
  });

  const PORT = 3000;
  app.listen(PORT, () => {
    console.log(`Listening on ${PORT}`);
  });
}

When I hit the endpoint using ab -c 2 -n 2 localhost:3000/, I get 10 seconds of wait time. Following are my observations:

1. Both the requests are being handled by two different child processes of node, which can be verified via the logs when this code is run.
2. Both of them are being executed sequentially.
3. I have tested the code on another machine as well which makes the chances of this being a cpu specific issue, very minimal.
4. To my knowledge, there is no code i.e. blocking.

I don’t think there is anything else I can do at this point. If I can, pls help me with comments.