Is there a way to redirect Post requests preserving post data or an alternative?

I am setting up a CDN relying o开发者_StackOverflownly on Header redirects or temporary URLs served by an API controlled by a Database cluster. The Goal is to reduce hardware costs and have flexible nodes with only FTP/HTTP/PHP as requirement and create a cheap solution for websites that can work with this.

Howevery my Problem is that i want to have a static Address where file uploads (containing ClientID and Token) can be sent to. I am using simple post. But the file should be sent directly to the most idle server.

So what I want is to have A Post request to http://whatever.com/upload.php which is redirected to http://server-in-cdn.whatever.com/upload.php whithout loosing the data. The problem is that the post request gets converted into a GET request and Post data is lost. The W3C documentation states that the 307 Header code could be used, but its not reliable and user confirmation is required.

Or is there an alternative? I am not really into network stuff... but I think the classic solution would be some sort of Load balancer or router running BGB/Quagga or something like that, and the traffic would still go over that node.. is that correct? Or is there a way to totally redirect the traffic on Network/DNS basis?

Thanks in advance.