Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am attempting to simulate my site's production environment as closely as I can on my local machine. This is a rails site that uses Apache w/ mod_proxy to forward requests to a mongrel cluster. On my Mac OSX Leopard machine, I have the default install of apache running and have configured a vhost to use mod_proxy to to forward requests to a local running mongrel instance on port 3000.

<Proxy balancer://mongrel_cluster-development>

For the most part, this is working fine. I can browse my development site using the ServerName of the vhost I configured and can confirm that requests are being properly forwarded to the mongrel instance. However, there is a page on the site that has a multipart form that is used to upload an image to the server. When I post this form, there is a delay of about 5 minutes and the browser ultimately returns a

Bad Request
Your browser sent a request that this server could not understand.

In the error log for my vhost:

[Tue Sep 22 09:47:57 2009] [error] (70007)The timeout specified has expired: proxy: prefetch request body failed to ( from ::1 ()

This same form works fine if I browse directly to the mongrel instance ( Anybody have any idea what the problem might be and how to fix it? If there is any important information that I neglected to include, post a comment, and I can add to this question.

Note: Upon further investigation, this appears to be a problem specific to Safari. The form works fine in Firefox.

share|improve this question
Do you have ProxyPass and ProxypassReverse lines? Those might be what you're looking for. – KM. Aug 20 '12 at 1:41

I think this problem cause by the limit of a cookie-header length.

The cookie-header's limitation of 'RFC 2109' is below:

  • at least 300 cookies
  • at least 4096 bytes per cookie
  • at least 20 cookies per unique host or domain name

When Safari send a large cookie header in sometime, Apache could not parse it. You may have to check the session header by using tcpmon (or like that).

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.