error on long lasting ajax calls

schulzki · Post by **schulzki** » April 11th, 2015, 3:04 am

Hi,

since FF V35, long lasting ajax requests are canceled with an error after a random amount of time.
The error is a status 404 but not a reply from the server.
With a processing delay of 100 Secs the error happens with >95% of the requests, with a high variance
(somtetimes after 10 secs, sometimes after 70 secs).

I tested ajax requests without lib support as well as jQuery.
I also checked different appserver versions (Jetty 6, 8, 9)

No error on FF <= Version 34 (also no error on other browsers).

Can sb. please verify this?

thx, schulzki

Post by **LoudNoise** » April 11th, 2015, 9:00 am

Moving to Web Development to give those folks a look at this. Can you provide a link to something showing the problem?

Post by **trolly** » April 11th, 2015, 11:21 am

To my knowledge 404 is a server side error.
http://en.wikipedia.org/wiki/HTTP_404

jscher2000 · Post by **jscher2000** » April 11th, 2015, 7:50 pm

I think if a high percentage of AJAX calls were randomly cancelled in Firefox 35-37, there would be a large volume of posts about it on Mozilla-related forums and on sites like StackOverflow. I can't recall seeing that.

Could it be something Jetty-specific?

Post by **LoudNoise** » April 11th, 2015, 9:02 pm

As noted, a link to the problem would be welcomed.

schulzki · Post by **schulzki** » April 12th, 2015, 5:12 am

ok, here is some more info:

I can reproduce it with apache/PHP so it is not jetty.
The 404 is the status delivered in the ajax callback, however, the status reported on firebug network table is "aborted"
I don't have a link illustrating the problem in production (only integration), but it is very easy to reproduce if you have apache/PHP installed. I provide some code beneath

To reproduce the problem, you only need these 2 files.
The index.html provides a button that simply triggers an ajax request loading info.php, which delays the answer for 100sec.

index.html

Code: Select all

<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>Ping WS</title>
    <script type="text/javascript">
   function debug(text){
      document.getElementById("debug").innerHTML = text;
   }
   
    function callAjax(url, success, error){
      var xmlhttp;
      xmlhttp = new XMLHttpRequest();
      xmlhttp.onreadystatechange = function(){
         if (xmlhttp.readyState == XMLHttpRequest.DONE ){
            if( xmlhttp.status == 200){
               success(xmlhttp.responseText);
            } else {
               error(xmlhttp.responseText);
            }
         }
      }
      xmlhttp.open("GET", url, true);
      xmlhttp.send();
   }

      function longping(){
            start = new Date().getTime();
         debug("long call...")
            callAjax(
                window.location.origin + "/info.php",
                function(){
               var dur = new Date().getTime() - start;
               debug("ok: " + dur);
            }, 
            function(e){
               var dur = new Date().getTime() - start;
               debug("ko: "  + dur);
            });
        };


    </script>
</head>
<body>
<button onclick="longping()">fire</button>
<div id="debug">debug</div>
</body>
</html>

info.php

Code: Select all

<?php

echo "waiting\n";

usleep(100000000);
?>

jscher2000 · Post by **jscher2000** » April 12th, 2015, 10:38 am

Test page: http://jeffersonscher.com/res/ajax100.html

I got normal results on my regular profile. I got one out of four abnormal results on a clean profile; I don't have an explanation for that.

Post by **trolly** » April 12th, 2015, 12:46 pm

10 times, 10 times ok ...

Network issue?? Wireshark log available maybe?

schulzki · Post by **schulzki** » April 13th, 2015, 4:02 am

trolly wrote:10 times, 10 times ok ...

Network issue?? Wireshark log available maybe?

I can reproduce the issue running client and server on the same machine, so most prob. no network problem.

I found this issue when I detected loads of logfile entries for a productive client (It uses a framework with long polling ajax requests for comet push), so it is reproducible in different environments.

But strange that it is not fully reproducible on all FFV35+.....

Post by **trolly** » April 13th, 2015, 5:05 am

BTW: I got this result:

GET XHR http://jeffersonscher.com/res/info.php [HTTP/1.1 200 OK 100359ms]
GET XHR http://jeffersonscher.com/res/info.php [HTTP/1.1 200 OK 6ms]
GET XHR http://jeffersonscher.com/res/info.php [HTTP/1.1 200 OK 100345ms]

The middle one had a response time of only 6 ms.

schulzki · Post by **schulzki** » April 13th, 2015, 7:15 am

just realized I never mentioned I use FF on windows (win7 64 bit), what is your OS?

Post by **trolly** » April 13th, 2015, 7:32 am

Firefox Nightly 40 x64 on WXP and W7/64.

BTW We knew. Your user agent at least gave away your OS.

error on long lasting ajax calls

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