Slow uploads Nginx and Gluster - django

Question

We are having trouble with uploads to my site with django, gunicorn, running behind nginx. we also have a gluster mount on the app server where the files are uploaded and distributed-replicated across several servers. (All tiers are on AWS)
When we go to upload a file(~15mb), we get a 502 Bad Gateway. we also check the nginx logs which show a upstream prematurely closed connection while reading response header from upstream, client. Our upload speeds are being extremely slow (<5k). we can upload to other sites just fine, and our internet upload is around 10MB with anything else.
Is there any configuration file that I am missing to allow uploads of a file through gunicorn or nginx?
nginx.conf
user www-data;
worker_processes 4;
pid /run/nginx.pid;
events {
worker_connections 768;
# multi_accept on;
}
http {
##
# Basic Settings
##
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
# server_tokens off;
server_names_hash_bucket_size 256;
# server_name_in_redirect off;
include /etc/nginx/mime.types;
default_type application/octet-stream;
##
# Logging Settings
##
access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;
##
# Gzip Settings
##
gzip on;
gzip_disable "msie6";
# gzip_vary on;
# gzip_proxied any;
# gzip_comp_level 6;
# gzip_buffers 16 8k;
# gzip_http_version 1.1;
# gzip_types text/plain text/css application/json application/x-javascript text/xml
application/xml application/xml+rss text/javascript;
##
# nginx-naxsi config
##
# Uncomment it if you installed nginx-naxsi
##
#include /etc/nginx/naxsi_core.rules;
##
# nginx-passenger config
##
# Uncomment it if you installed nginx-passenger
##
#passenger_root /usr;
#passenger_ruby /usr/bin/ruby;
##
# Virtual Host Configs
##
include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;
}
conf.d files:
client_max_body_size 256m;
_
proxy_read_timeout 10m;
proxy_buffering off;
send_timeout 5m;
_
We have a feeling that it may be either nginx or the gluster mount. We have been working on this for days, and have looked all through the timeout* variables in nginx and gunicorn and haven't made any progress.
Any help would be appreciated, Thank you!

Answer 1

So, we solved the problem. It had nothing to do with any of our code, server setup, or amazon. We narrowed it down to only linux machines uploading in our network. there was a bug with 'tcp window scaling' in the firewall that was resetting the upload after it reaches a limit.
Thanks for anyone that attempted.