[Python] 502 Bad Gateway upstream prematurely closed connection while reading response header...

how are you? I have a server on DigitalOcean with Ubuntu 16.04 I am making a Flask Application with uWSGI and Nginx.

My files look like: wsgi.py:

from flaskapp import app
if __name__ == "__main__":
app.run()


flaskapp.ini

[uwsgi]
limit-as = 512
module = wsgi:app
plugin = python
master = true
processes = 5
socket = flaskapp.sock
chmod-socket = 660
vacuum = true
die-on-term = true


/etc/systemd/system/flaskapp.service

[Unit]
Description=uWSGI instance to serve flaskapp
After=network.target

[Service]
User=blitwak
Group=www-data
WorkingDirectory=/home/blitwak/flaskapp
Environment="PATH=/home/blitwak/flaskapp/myprojectenv/bin"
ExecStart=/home/blitwak/flaskapp/myprojectenv/bin/uwsgi --ini flaskapp.ini

[Install]
WantedBy=multi-user.target


/etc/nginx/sites-available/flaskapp.conf

server {
listen 80;
server_name 162.243.76.55;

charset utf-8;
proxy_buffering on;
proxy_buffer_size 1k;
proxy_buffers 24 4k;
proxy_busy_buffers_size 8k;
proxy_max_temp_file_size 2048m;
proxy_temp_file_write_size 32k;

proxy_connect_timeout 75s;
proxy_read_timeout 300s;


location / {
include uwsgi_params;
uwsgi_pass unix:///home/blitwak/flaskapp/flaskapp.sock;

uwsgi_param UWSGI_SCRIPT app.wsgi;

uwsgi_buffer_size 32k;
uwsgi_buffers 8 32k;
uwsgi_busy_buffers_size 32k;


}
}


and in /var/log/nginx/error.log it says a lot of times:

2017/01/19 15:58:18 [error] 19181#19181: *36 upstream prematurely closed connection while reading response header from upstream, client: {myip}, server: {myserver}, request: "POST /yajugue HTTP/1.1", upstream: "uwsgi://unix:///home/blitwak/flaskapp/flaskapp.sock:", host: "{myserver}", referrer: "http://{myserver}/jugarPrimeraVez"
​

Thank you very much!!!

How can I resolve it?

Continue reading...