Why NodeJS KeepAlive does not seem to work as expected?

Question

Quoted from TCP keepalive HowTo:

In order to understand what TCP keepalive (which we will just call keepalive) does, you need do nothing more than r

Answer 1

https://www.npmjs.com/package/net-keepalive

Here is a module which lets you configure TCP_KEEPINTVL and TCP_KEEPCNT per-socket basis.

Provides high-level access to socket options like TCP_KEEPIDLE, TCP_KEEPINTVL, TCP_KEEPCNT

var Net = require('net')
  , NetKeepAlive = require('net-keepalive')
;

// Create a TCP Server
var srv = Net.createServer(function(s){>
  console.log('Connected %j', s.address())
  // Doesn't matter what it does
  s.pipe(s)
});

// Start on some port
srv.listen(1337, function(){
  console.log('Listening on %j', srv.address())
});

// Connect to that server
var s = Net.createConnection({port:1337}, function(){
  console.log('Connected to %j', s.address())

  //IMPORTANT: KeepAlive must be enabled for this to work
  s.setKeepAlive(true, 1000)

  // Set TCP_KEEPINTVL for this specific socket
  NetKeepAlive.setKeepAliveInterval(s, 1000)

  // and TCP_KEEPCNT
  NetKeepAlive.setKeepAliveProbes(s, 1)
});