Limit a form post size with Apache / Django – clarification

I believe you should be able to do this with Apache's LimitRequestBody method.

The LimitRequestBody directive allows the user to set a limit on the allowed size of an HTTP request message body within the context in which the directive is given

...

If, for example, you are permitting file upload to a particular location, and wish to limit the size of the uploaded file to 100K, you might use the following directive:

LimitRequestBody 102400 

Why don't you double check the size of the POST request. For example, you can use netcat to listen on 8080.

netcat -l -p 8080

Then, redirect your browser to use a proxy on port 8080 just before submitting the form. You should get something like this:

POST http://example.com/path/to/my/wiki/index.php HTTP/1.1
Host: example.com
Proxy-Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
Content-Length: 217

The most important line is Content-Length and just double check the actual length of the content. That will at least help you to determine where things are going wrong. You will at least have an idea of the actual content size.

Then, ensure that you are directly connecting to Apache and not through either a proxy or a reverse-proxy. Some reverse-proxies place a cap on the maximum size of a request as a sort of security measure. So, you may want to check that as well as your Apache logs to ensure that nothing else is going on.