Scaling Node

Accessing the OS

We can get information about our machine, including the number of cores using the os module.

var os = require(‘os’); os.cpus();

Cluster Module

We can use the cluster module to spark up a new server on each CPU. The CPUs will not share state, but will share a port. A simple round robin router will direct traffic between the cores

read more about the cluster module here:

https://nodejs.org/api/cluster.html

var cluster = require("cluster"),
  http = require("http"),
  os = require("os"),
  cpus = os.cpus().length;

console.log(cluster);

if (cluster.isMaster) {
  for (var i = 0; i < cpus; i++) {
    cluster.fork();
  }
  cluster.on("exit", function (worker, code, signal) {
    cluster.fork();
  });
  console.log("listening on port 3001");
} else {
  http
    .createServer(function (req, res) {
      res.writeHead(200);
      res.write("Hello Cluster!!");
      res.end;
    })
    .listen(3001);

  console.log("Making child process");
}

Exercise - Scaling

Find the number of cores on your machine.

Scale your app across all of your cores.

Downloads

Code samples (Dropbox)