Why is AJAX returning HTTP status code 0?

Question

For some reason, while using AJAX (with my dashcode developed application) the browser just stops uploading and returns status codes of 0. Why does this happen?

Answer 1

We had similar problem - status code 0 on jquery ajax call - and it took us whole day to diagnose it. Since no one had mentioned this reason yet, I thought I'll share.

In our case the problem was HTTP server crash. Some bug in PHP was blowing Apache, so on client end it looked like this:

mirek@toccata:~$ telnet our.server.com 80
Trying 180.153.xxx.xxx...
Connected to our.server.com.
Escape character is '^]'.
GET /test.php HTTP/1.0
Host: our.server.com

Connection closed by foreign host.
mirek@toccata:~$ 

where test.php contained the crashing code. No data returned from the server (not even headers) => ajax call was aborted with status 0.