I get 502 and 504 error from nginx in node.js

Question

I changed the config file to increase the time and uploading size and doesn't found the php-fsm file. whenever I try to click after some time it stuck and gives 504 error and then 502 error every time.

This is my nginx.conf file.. which is located on etc/nginx/nginx.conf Please give me the solution for this issue as my project is on hold because of these things and i need to launch my web app as soon as possible.

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

events {
	worker_connections 768;
	# multi_accept on;
}

http {

	##
	# Basic Settings
	##

	sendfile on;
	tcp_nopush on;
	tcp_nodelay on;
	keepalive_timeout 600;
	types_hash_max_size 2048;
        
        # set client body size to 500M #
        
       

        proxy_connect_timeout       600;
        proxy_send_timeout          600;
        proxy_read_timeout          600;
        send_timeout                600; 

        
        client_header_timeout 3000;
        client_body_timeout 3000;
        fastcgi_read_timeout 3000;
        client_max_body_size 800m;
        fastcgi_buffers 8 128k; 
        fastcgi_buffer_size 128k;

        #client_max_body_size 800M;
        #client_header_timeout 3000;
        #client_body_timeout 3000;
        #fastcgi_read_timeout 3000;
         #client_max_body_size 800m;
        #fastcgi_buffers 8 128k; 
        #fastcgi_buffer_size 128k;
        #proxy_connect_timeout       600;
        #proxy_send_timeout          600;
        #proxy_read_timeout          600;
        #send_timeout                600; 
	# server_tokens off;

	# 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/*;
}


#mail {
#	# See sample authentication script at:
#	# http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript
# 
#	# auth_http localhost/auth.php;
#	# pop3_capabilities "TOP" "USER";
#	# imap_capabilities "IMAP4rev1" "UIDPLUS";
# 
#	server {
#		listen     localhost:110;
#		protocol   pop3;
#		proxy      on;
#	}
# 
#	server {
#		listen     localhost:143;
#		protocol   imap;
#		proxy      on;
#	}
#}