Please help - "fastcgi request record is too big" - no idea

[Michael Shadle]

We're hitting this with a simple AJAX-based file upload. The file
being uploaded is only 199862 bytes.

The debug output is here. I masked the hostnames and IPs (with the
same length though, just in case) to protect the innocent.

http://pastebin.com/7k6PihVN

I am not sure if these are relevant or not, but it should be tuned to
allow file uploads up to at least 100 megs. It works great, but for
some reason this request is not working.

Here's anything possibly relevant to any kind of proxy
buffers/handling/etc/etc :p

sendfile on;
tcp_nopush on;
tcp_nodelay on;
ignore_invalid_headers on;
client_max_body_size 251m;
client_header_buffer_size 8k;
client_body_buffer_size 416k;
large_client_header_buffers 16 8k;
keepalive_timeout 30;

proxy_buffer_size 16k;
proxy_buffers 16 8k;

server_names_hash_max_size 4096;
server_names_hash_bucket_size 128;

fastcgi_ignore_client_abort on;
fastcgi_intercept_errors on;
fastcgi_buffers 32 8k;
fastcgi_buffer_size 8k;
fastcgi_busy_buffers_size 16k;
fastcgi_read_timeout 120;
fastcgi_param UNTOUCHED_BODY $request_body;

Thank you!