Promise.all processes the promises in a group of 6 at each time

Question

I wanna make a bunch of (let's say 20) HTTP POST requests (in order to send information of an app to some HTTP servers) simultaneously.

I am using http angular service to return a promise:

function deployPromise(server, app){
  return $http({
    method: 'POST',
    url: server.url,
    data: app
  });
}

For simultaneous deployments I am using Promise.all that gets the array of deployPromises:

function deploy(servers, app){
  Promise.all(servers.map(function(server){
    return deployPromise(server, app);
  }));
}

Finally I call deploy function with array of available servers and the app info:

deploy(servers, app);

To my surprise, instead of executing all at once, requests are sent (in otherwords, deployPromises are resolved) in a group of 6. I mean, when the first 6 calls are done, then the second 6 calls will be processed and so on.

Do you guys have any idea?

If browsers didn't limit connections per host, all hell would break loose. — spender, Dec 08 '16 at 19:46
Sure but still I would too expect promises in parallel completing at the same time, despite being invoked in bulks. — cYrixmorten, Dec 08 '16 at 19:48
@cYrixmorten - how could they complete at the same time if the browser limits the number of simultaneous connections? — Jaromanda X, Dec 08 '16 at 20:25
@JaromandaX Not complete at the same time, but deferred until all are completed before by Promise.all — cYrixmorten, Dec 08 '16 at 20:43
Yes. Theres no indication in the question that this isn't happening — Jaromanda X, Dec 08 '16 at 21:36

score 4 · Accepted Answer · edited May 23 '17 at 12:24

4

This is a browser limitation, you can't open a infinite number of simultaneous connections. Max parallel http connections in a browser?

edited May 23 '17 at 12:24

Community

1
1

answered Dec 08 '16 at 19:42

Hitmands

13,491
4
34
69

Promise.all processes the promises in a group of 6 at each time

1 Answers1