Plesk Error: 751#0: *1308343 connect() failed (110: Connection timed out) while connecting to upstream
Under certain circumstances, it could happen that your web server is no longer accessible and the browser displays the error code 502. This error occurs especially with Shopware.
If a look into the logs of the web server shows you the error
Plesk error: 751#0: *1308343 connect() failed (110: Connection timed out) while connecting to upstream
Do I have a quick solution to fix the problem.
Open the nginx configuration
nano /etc/nginx/nginx.conf
and adjust the number of worker processes and connections according to your hardware.
After that add the following settings in the http settings section:
proxy_connect_timeout 600;
proxy_send_timeout 600;
proxy_read_timeout 600;
send_timeout 600;
After that you just have to restart the service and everything should work again
service nginx restart