Reverse Proxy File Upload Failure

[Nicholas J Ingrassellino]

I am running Nginx v1.8.0 to serve all my static files and node.js to do 
the dynamic stuff. One of the things Nginx needs to do is proxy files 
over to node.js which stores the file. node.js seems to get ~26K of the 
file and then nothing (not even sure the connection closes when the data 
"finishes" sending).

My configuration is so:
location /attachment_upload/ {
     client_body_temp_path /tmp/;
     client_body_in_file_only clean;
     client_body_buffer_size 256k;
     client_max_body_size 1g;

     proxy_set_header X-FILE $request_body_file;
     proxy_http_version 1.1;
     proxy_buffering off;
     proxy_pass http://10.10.1.20:8090/attachment_upload/;
     expires epoch;
}

I had setup curl to see if I could get more information. It returns 
right away (so it does not look like a time-out to me) without error. I 
have checked the Nginx error logs and do not see anything in there.

Not sure what to check next...