This is not a typical xml-dev thread, unless someone wants to wax 
philosophical about the impact of AJAX on debugging.

You didn't say what the fault symptoms were, but I guess from your 
"Heavy server load..." message that nothing is downloaded at all. You 
don't say if there is a continuous busy-download status.

You wrote "but later it will fail." Is there a substantial time lapse 
over the course of your testing that may incur a session timeout? How 
long is after you start is "later" for your testing? Are you logged in 
as a member?  Does the site use a dummy session for those browsing 
without an account?

Off the top of my head... things that appear erratic during testing...
- a race condition in the client or a wrong value in a Javascript 
variable, due to an asynchronous setTimeout() or XMLHttpRequest callback
- server-side race conditions in database handling code
- a server-side global that is not being set consistently
- sessions that are timing out, or which are stored in a temp directory 
that is being wiped periodically

- Mitch Amiano

Tri-XML 2006 Conference
http://www.trixml.org/confschedule.shtml 
- July 27-29, 2006
- Beautiful, warm Raleigh, NC USA
- $450 regular rate for 3 day conference on XML



Scott Abel wrote:
> Hello fellow XML Pros...
>
> Just curious if anyone has any experience debugging AJAX application 
> problems. I have added (actually my developer has) an AJAX 
> functionality to my Expression Engine-powered blog that allows users 
> to filter events (filter out those that don't interest them by 
> selecting a category). When the user selects a category the lengthy 
> list of events shortens, displaying only events that meet the criteria 
> of the category selected.
>
> Unfortunately, this functionality does not work consistently. Instead 
> of removing the feature (it works sometimes), we have added a message 
> that tells the user "Due to heavy server load, we were unable to 
> retrieve events for you." This message is purely to prevent the user 
> from waiting forever for the AJAX list to work.
>
> What I don't know is why this problem occurs in the first place. When 
> I ask some folks to test it, they don't see the bug. The AJAX works 
> fine. Then, I'll go back and test the list myself and it will work, 
> but later it will fail.
>
> Any ideas? Any suggestions? Please email me directly (in addition to 
> copying those on the list) as I am traveling and may not be able to 
> access list email easily.
>
> Here's the URL of the site: www.thecontentwrangler.com
>
> Thanks in advance for any suggestions.
>
> The Content Wrangler, Inc.
> Scott Abel, Content Management Strategist
> 3421 Crystal Lakes Ct., Sarasota FL 34235
> abelsp@n...      941-359-3416
> www.thecontentwrangler.com
> Via Skype: abelsp
>
>