NodeJS как исправить 502 ошибку при загрузке файлов?

Question

[John Doe]

Имеется сайт на NodeJS фреймворке AdonisJS. Все бы ничего, но при загрузке файлов свыше 2Мб сервер ложится на 502 ошибке. В лог пишет

2016/12/03 12:25:12 [error] 2034#2034: *2504 upstream prematurely closed connection while reading response header from upstream, client: 37.215.112.153, server: adonis.ml, request: "POST /manager/albums/1/ HTTP/1.1", upstream: "127.0.0.1:3000/manager/albums/1", host: "adonis.ml", referrer: "https://adonis.ml/manager/albums/1/"

Привожу весь файл конфигурации Nginx ( /etc/nginx/nginx.conf )

user www-data;
worker_processes auto;
pid /run/nginx.pid;

events {
	worker_connections 768;
	# multi_accept on;
}

http {
	client_max_body_size 100M;

	##
	# Basic Settings
	##

	sendfile on;
	tcp_nopush on;
	tcp_nodelay on;
	keepalive_timeout 3600s;
	types_hash_max_size 2048;
	# server_tokens on;

	# server_names_hash_bucket_size 64;
	# server_name_in_redirect off;

	include /etc/nginx/mime.types;
	default_type application/octet-stream;

	##
	# SSL Settings
	##

	ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
	ssl_prefer_server_ciphers on;

	##
	# 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/javascript text/xml application/xml application/xml+rss text/javascript;

	##
	# Virtual Host Configs
	##

	include /etc/nginx/conf.d/*.conf;
	include /etc/nginx/sites-enabled/*;
}

В настройках самого фреймворка стоит разрешение на загрузку файлов до 2Гиг
Помогите пожалуйста решить проблему 502

Конфиг хоста

server { 
      listen 443 ssl; 
      ssl on; 
      ssl_certificate /etc/letsencrypt/live/adonis.ml/fullchain.pem; 
      ssl_certificate_key /etc/letsencrypt/live/adonis.ml/privkey.pem; 

      root /gopanel/sites/adonis_ml/public_html; 
      index index.php index.html index.htm; 

      server_name adonis.ml; 

      include /etc/roundcube/webmail_configuration;
      include /etc/phpmyadmin/nginx.conf;

     location / {
        proxy_read_timeout  2400s;
        proxy_pass http://127.0.0.1:3000;
        proxy_set_header Host $host;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }

      location ~ \.php$ { 
           try_files $uri =404; 
           fastcgi_pass unix:/var/run/php/php7.0-fpm.sock; 
           fastcgi_param HTTP_PROXY ""; 
           fastcgi_index index.php; 
           fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; 
           include fastcgi_params; 
      } 
}