How to handle sending out multiple http request in Node?

I have the standard code for sending out http request. Using http.globalAgent.

I set my maxSockets be 2500.

And then when I send out multiple requests at once, I get this error:

['{'code':'ECONNRESET'}']

However, if I sent out the request after a bit of timeout between each request, then it works.

So, questions are:

1) what does ECONNRESET really mean? Why this error happen?

2) How to send out multiple requests instantly without getting that error?

original code to send out multiple requests:

// I'm using Seq()
Seq().
 seq(function() {
  this(null, ['p1','p2','p3','p4','p5']);
})
.flatten(false)
.parEach(fuctnion(data) {
  // send out request
  sendRemoteRequest(data);  // a function that uses http.request
})
.seq(function(data) {
  console.log("done");
})