Django 502 bad gateway with Nginx and Uwsgi - django

Question

I can normally open up my web in the front several hours after deployment,but later , it occurred 502 bad gateway ,it is so wired, my web uses Django and Nginx and Uwsgi, i do research a lot on google,but failed with nothing
Here is my configuration:
1.Nginx configuration
# mysite_nginx.conf
upstream django {
server 127.0.0.1:8004; # for a web port socket (we'll use this first)
}
server {
listen 80;
server_name www.example.com # substitute your machine's IP address or FQDN
charset utf-8;
client_max_body_size 75M; # adjust to taste
location /media {
alias /home/blender_font_project/django_file/Blender_website/media;
}
location /static {
alias /home/blender_font_project/django_file/Blender_website/static;
}
location / {
uwsgi_pass 127.0.0.1:8003;
include /etc/nginx/uwsgi_params;
}
}
2.uwsgi configuration
# mysite_uwsgi.ini file
[uwsgi]
chdir = /home/blender_font_project/django_file/Blender_website
module = djangoTest5.wsgi
master = true
processes = 10
socket = :8003
vacuum = true
harakiri=60
daemonize=/home/blender_font_project/uwsgi_file/real3dfont_logfile
3.this is my Nginx error log
231 connect() failed (111: Connection refused) while connecting to upstream
BTW , i have set Django to DEBUG Ture and i can access my resource by www.example.com/static/example.jpg,but the web page shows 502
I really dont know why , thanks if you offer any help!

Answer 1

(...After million years struggle and strive,with inspiration from a super hero in comment named #Atul Mishra , i finally figure it out...)
It is the matter Django itself,i forget to download mysql module in View , i would have expect a Django error html if it is the django problem, but no , so i mistakenly attribute it to Nginx or Uwsgi
But the wired thing is that Django should have report the error , but no ! what an irresponsible dude!!
so , 1.remember to add Django error log function ,it saves your life , and
2.test Django with runserver before Nginx enter the stage even when comet is striking the earth!!