For a dynamic page, I use Ajax Long Polling and even with jQuery 1.9, Internet Explorer hangs after the first request.

The script code is based on the article Simple Long Polling Example with JavaScript and jQuery

 <script type="text/javascript" charset="utf-8"> 
   $(document).ready(function(){ 
     (function poll(){
       $.ajax({ url: "ajaxstats.json", success: function(data){
         $("button.requests" ).empty().append(data.requests);
   }, dataType: "json", plete: poll, timeout: 30000 });
     })();
   });
 </script>

The console shows no errors.

The IE network monitor immediately shows many requests to the ajaxstats.json resource with a response time of < 1 ms and a 304 (not modified) response code. The response body is correct (JSON code).

The server code always delays the answer by 1000 milliseconds. And in Firefox, Firebug XHR log shows that every request takes around 1000 milliseconds, as expected.

The HTTP response code is different between Firefox and Internet Explorer:

• in Firefox: response code is 200 ok
• in Internet Explorer 9, the response code is 304 (not modified)

Is there a way to work around this IE problem?

For a dynamic page, I use Ajax Long Polling and even with jQuery 1.9, Internet Explorer hangs after the first request.

The script code is based on the article Simple Long Polling Example with JavaScript and jQuery

 <script type="text/javascript" charset="utf-8"> 
   $(document).ready(function(){ 
     (function poll(){
       $.ajax({ url: "ajaxstats.json", success: function(data){
         $("button.requests" ).empty().append(data.requests);
   }, dataType: "json", plete: poll, timeout: 30000 });
     })();
   });
 </script>

The console shows no errors.

The IE network monitor immediately shows many requests to the ajaxstats.json resource with a response time of < 1 ms and a 304 (not modified) response code. The response body is correct (JSON code).

The server code always delays the answer by 1000 milliseconds. And in Firefox, Firebug XHR log shows that every request takes around 1000 milliseconds, as expected.

The HTTP response code is different between Firefox and Internet Explorer:

• in Firefox: response code is 200 ok
• in Internet Explorer 9, the response code is 304 (not modified)

Is there a way to work around this IE problem?

• javascript
• jquery
• ajax
• internet-explorer-9

• 1 any errors in the console? what about the http traffic? – jbabey Commented Jan 31, 2013 at 14:08
• @jbabey see my edit, I will update it with my findings in Firefox – mjn Commented Jan 31, 2013 at 14:18
• Did you clear you cache? You are making a GET request which will cache the http response. Set the cache option to the ajax call if you want jQuery to add a cache breaking querystring parameter to the call. – epascarello Commented Jan 31, 2013 at 14:27
• on a side note, one of the ments on the linked article already covered this: "are you sure the timeout param in $.ajax works that way, i.e. to delay the next execution by at least 30 seconds? Because i think it just sets a maximum timeout for the call. When I tried it just now the function kept firing AFAICT as fast as it could loop." – jbabey Commented Jan 31, 2013 at 15:09
• @jbabey I guess this is as designed, I delay the response for exactly this reason - avoid overloading the client. In other words: the server controls when the next refresh of the page will happen. – mjn Commented Jan 31, 2013 at 15:16

3 Answers 3

Try setting cache param to false, if set to false, it will force requested pages not to be cached by the browser.

 <script type="text/javascript" charset="utf-8"> 
   $(document).ready(function(){ 
     (function poll(){
       $.ajax({ url: "ajaxstats.json", success: function(data){
         $("button.requests" ).empty().append(data.requests);
   }, dataType: "json", plete: poll, timeout: 30000, cache: false });
     })();
   });
 </script>

Use the setTimeout version on the article. The timeout option sets the timeout for the request, not the time to wait until the next request.

There's a reply to a ment from Lars, where the author suggests that.

I don't have a good answer on why IE9 hangs other than the fact that IE9 is just slow. It will intermittently take forever to call the callback of an ajax call. Testing at work, I've seen the same ajax call against the same server take more than 5x the time in IE9 as it does in Firefox, even though the browsers are running on the same machine.

If you are building a real time app and have access to the actual server it is running on I highly remend you use Socket.IO. http://socket.io/ Originally it was built for node.js but there are server side implements now for most of the major languages.

The client library has this fall back order:

• WebSocket
• Adobe Flash Socket
• AJAX long polling
• AJAX multipart streaming
• Forever Iframe
• JSONP Polling

On the newer browsers you get true web socket performance, on those that don't support it you get long polling for free but you get to just treat it as a web socket using the same clean Socket.IO interface.