Concurrent Ajax Calls?

Question

I need to call a particular PHP script on my server several times. As each call will take some time (e.g. about .5 seconds) and each call is independent of each other, I want to call the scripts concurrently. Right now, I have something like this:

$(document).ready(function() {

    $.ajax({
      url: 'main.php',
      method: 'POST',
      data: { foo: 'foo' },
      success: function(result) {
        console.log(result);
      }
    });

    $.ajax({
      url: 'main.php',
      method: 'POST',
      data: { bar: 'bar' },
      success: function(result) {
        console.log(result);
      }
    });

});

Instead of making these calls sequentially, I want to do them concurrently. How do I do that?

What is not concurrent with what you have shown ? There is no way to achieve two independent calls beside the one you're using. — elad.chen, Aug 24 '15 at 19:06
ajax is asynchronous! Look at your network in dev tools , will see they are concurrent — charlietfl, Aug 24 '15 at 19:07
Javascript only has one thread. As long as you don't have global ajax settings causing the requests to be synchronous, that's about as concurrent as it gets. — Stryner, Aug 24 '15 at 19:07

MonkeyZeus · Accepted Answer · 2015-08-24T19:52:35.757

Not sure what issue you are experiencing but you are making concurrent AJAX calls because jQuery defaults to async: true. If it defaulted to false then it would be called SJAX lol

One issue which you might be experiencing would be a session handling lockup.

If main.php is using session_start() then it will simply queue the bar request until foo finishes. Or you can manually call session_write_close() to avoid the lockup.

score 0 · Answer 2 · answered Aug 24 '15 at 19:06

Set your async = true on your AJAX calls to make them asynchronous.

$.ajax({
    async: "true",
      url: 'main.php',
      method: 'POST',
      data: { foo: 'foo' },
      success: function(result) {
        console.log(result);
      }
    });

    $.ajax({
    async: "true",
      url: 'main.php',
      method: 'POST',
      data: { bar: 'bar' },
      success: function(result) {
        console.log(result);
      }
    });

score 0 · Answer 3 · answered Aug 24 '15 at 19:09

0

Ajax requests are asynchronous by nature. Based on your example, each of the calls will be dispatched without waiting for the server's response

answered Aug 24 '15 at 19:09

elad.chen

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That cannot be assumed. We would need to see the PHP code. – MonkeyZeus Aug 24 '15 at 19:13
1

How will the PHP backend affect the client from sending multiple requests? – elad.chen Aug 24 '15 at 19:17
It could have a ripple effect and cause the client to reach its [concurrent connections limit](http://stackoverflow.com/questions/985431/max-parallel-http-connections-in-a-browser). – MonkeyZeus Aug 24 '15 at 19:51

Concurrent Ajax Calls?

3 Answers3