little_server.js

var express = require('express')
var app = express();
var expressWs = require('express-ws')(app);
var si = require('systeminformation');

const port = 4000
var totalSubs = 0
app.ws('/sub', (ws, req) => {
  totalSubs += 1;
  console.log('Total subscriptions : '+totalSubs);
  setInterval(() => {
    si.processes(data => { ws.send(data.all) } )
  }, 500)
  ws.send('fetching...');
});

app.listen(port, () => {
  console.log('Little server started on '+port);
});