502 bad gateway nginx shiny file upload - nginx

Question

I have uploaded a big file (5Gb) using fileUpload. I have increased the file upload limit to 10Gb in the shiny server code. The file upload succeeds but returns the error after the upload is completed:
Error : html head title 502 bad gateway /title /head
Below are my config info:
options(shiny.maxRequestSize = 10000 * 1024 ^ 2)
The nginx config /etc/nginx/nginx.conf has the basic settings in http block as below:
http {
map $http_upgrade $connection_upgrade {
default upgrade;
'' close;
client_max_body_size 100G;
large_client_header_buffers 8 64k;
}
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
# server_tokens off;
# server_names_hash_bucket_size 64;
# server_name_in_redirect off;
include /etc/nginx/mime.types;
default_type application/octet-stream;
}
The /etc/nginx/sites-available/default configuration is as shown below:
server {
listen 80 default_server;
listen [::]:80 default_server
root /var/www/html;
# Add index.php to the list if you are using PHP
index index.html index.htm index.nginx-debian.html;
server_name _;
location /shiny/ {
proxy_pass http://X.X.X.X:3838/;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
rewrite ^(/shiny/[^/]+)$ $1/ permanent;
}
location /rstudio/ {
proxy_pass http://X.X.X:8787/;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
rewrite ^(/rstudio/[^/]+)$ $1/ permanent;
client_max_body_size 100000M;
}
location / {
# First attempt to serve request as file, then
# as directory, then fall back to displaying a 404.
try_files $uri $uri/ =404;
proxy_buffer_size 16k;
proxy_buffers 8 32k;
proxy_busy_buffers_size 224K;
keepalive 64
}
Any hints to try will be helpful.

Answer 1

Adding the following lines to the location/ to the config file in sites-available/myApp.com fixed the issue:
location / {
proxy_http_version 1.1; // you need to set this in order to use params below.
proxy_pass http://XXXXXX.XX.XX:3838;
proxy_redirect http://XXXXXX.XX.XX:3838/ https://$host/;
proxy_set_header Host $http_host;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $connection_upgrade;
proxy_temp_file_write_size 64k;
proxy_connect_timeout 10080s;
proxy_send_timeout 10080;
proxy_read_timeout 10080;
proxy_buffer_size 64k;
proxy_buffers 16 32k;
proxy_busy_buffers_size 64k;
proxy_redirect off;
proxy_request_buffering off;
proxy_buffering off;
}