Why does my AJAX request return empty?

Question

WHAT I ALREADY LOOKED AT:

Failed to load resource: net::ERR_EMPTY_RESPONSE http://test.com

Failed to load resource under Chrome

Failed to load resource: net::ERR_EMPTY_RESPONSE when console not opened

Failed to load resource: net::ERR_EMPTY_RESPONSE

ERROR:

Failed to load resource: net::ERR_EMPTY_RESPONSE

CODE:

client

var load = 0;

    $( document ).ready(function() {
        if (load == 0) {
            load++;
            $.ajax({
                type: "POST",
                url: "/1/2",
                data: someData,
            }).done(function(response) {
                console.log("RESPONSE :"+response);
                if (response.charAt(0) == "F") {
                    localStorage.setItem("error_msg_local", response);
                } else if (response.charAt(0) == "L") {
                    localStorage.setItem("success_msg_local",response);
                } else {
                    localStorage.setItem("error_msg_local", "Internal error. Please try again.");
                }
            });
        }
    });

server

The request is sent with POST and will wait for the user to complete a certain action. If the user does nothing, after 120 seconds, "NO" is logged and "F" should be sent as a response.

router.post("/2", function(req, res, next){

        request.post({
            url: 'URL:Port',
            json: {  
              JsonData: JsonData,  
              timeout: "120000"  
            }
        },
        function (error, response, body) {
            if (!error && response.statusCode == 200) {
                if (body.status == "success") {
                    //User completed action within 120 seconds, so do stuff
                }
                else {
                    //120 elapsed without user completing action, body.status == "nothing", so execute this:
                    console.log("NO");
                    res.send("F");
                }
            }
            else {
                console.log("ERROR: "+error);
            }
        });
});

QUESTION:

I am intentionally waiting 120 seconds to test my code. Nothing is logged on the client, but "NO" is logged on the server, so I know that res.send("F") should have been sent as a response.

Yet, I received "Failed to load resource: net::ERR_EMPTY_RESPONSE" in my browser console as an error message and nothing happens.

Here is everything that logs out in my terminal (server logs):

POST /1/2 - - ms - -
NO
POST /1/2 - - ms - -
NO

Strangely enough, it seems the request is triggered multiple times although I have called it only once ?

I even added a load counter to make sure it gets called only once, but it seems it gets called twice.

What should I do to only have one AJAX request and actually get the proper response from my server ?

You're posting to `/1/2` but showing a POST handler for `/payment`, is that intentional? I'm not sure what you're trying to do inside that `/payment` handler, though. — Dave Newton, Jan 02 '18 at 19:17

score 2 · Accepted Answer · answered Jan 02 '18 at 19:42

The error description has it -- empty response. Your server received and logged the request, but sent nothing in return. It's possible the browser rejected the response such as for CORS, but I would expect a different error message in that case.

Do you have another means to test the URL, such as cUrl? I use Fiddler a bit to monitor and manipulate network traffic, which might be easier. Rule out the server before revisiting the client code.

Why does my AJAX request return empty?

1 Answers1