xmlhttprequest simultaneous request not working

Question

I'm trying to make "many" xhr request but it seems that every time it waits for the answer before making another request. It's like XHR makes a queue and always wait for the previous request to finish.

What can I do to run more simultaneous xhr request?

$('body').delegate('.download','click', function(evt){
        evt.preventDefault(); // Not related

        var xhr = new XMLHttpRequest();
        xhr.open('GET', "proxy.php?" + this.href, true);
        xhr.responseType = 'blob';

        xhr.onload = function() {
            if (this.status == 200) {              
                var blob = new Blob([this.response], {type:'audio/mp4'});

                console.log(blob.size);
                if(blob.size > 0){
                    $("<a>").attr({
                        download: name,
                        href: URL.createObjectURL(blob),
                        target: "_blank"
                    })[0].click();
                }
            }
        };  
        xhr.send();
    });

Yes and the same thing happens..Both worker are called together but the second XHR wait for the first XHR to finish — Gregory Wullimann, Dec 29 '15 at 17:22
How about opening new browser windows, make the requset, use post message to send the response and then close the windows? Just thoughts that may help.. not very familiar with the subject. — prieston, Dec 29 '15 at 18:24
Also second thought, use more variables or an array or object to store xhr.. the variable may be still in use untill the server respondes. — prieston, Dec 29 '15 at 18:30
use when library this will be solves the case look here: http://stackoverflow.com/questions/12429765/parallel-ajax-calls-in-javascript-jquery — Hamit YILDIRIM, Dec 31 '15 at 11:15

score 11 · Answer 1 · answered Dec 21 '15 at 23:17

11

Not a lot.

Browsers enforce a limit on:

The number of parallel HTTP requests to a given origin
The number of parallel HTTP requests in total (this is a larger limit)

If you split your requests between more originals you might find your constraint raised from the first to the second of the above.

answered Dec 21 '15 at 23:17

Quentin

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I've seen that the limit enforced by chrome should be of 6 maximum request, is that right? – Gregory Wullimann Dec 23 '15 at 12:31

score 2 · Answer 2 · answered Dec 30 '15 at 05:54

2

Try to find something about http2, there is some info. Http2 protocol have better supporting of parallel requests.

answered Dec 30 '15 at 05:54

Alex Nikulin

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xmlhttprequest simultaneous request not working

2 Answers2