HTTP status code 499 from long running requests

[justin]

Hello, I have long running requests upwards of five minutes that are called
via ajax (jQuery) (XHR), and hitting a backend PHP script.

I am seeing very strange behavior, intermittently calling the script twice,
even though in Chrome developers tools I only see a single XHR request in
the network pane. I know that it is running twice because in my backend PHP
script I write a log to a MySQL database, and I am seeing two entries.

I took a look at the nginx access log, and seeing HTTP status code 499,
which seems to be: client closed connection before nginx
was able to send anything to client.

What is the best way to fix this? Is there a config setting in nginx to keep
the connection open? Or is the client terminating the request, and then
reissuing the request, thus way I am seeing two entries?

Thanks for the help with this.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,239759,239759#msg-239759