Most of the time we face an error called 503 but in python / nodejs applications which is running in a WHM server with cloudlinux
Here is the solution:
First step is to check your litespeed & cloudlinux license. If you don’t have license that can be a cause of this 503 issue then check litespeed version sometimes you might face issue with the litespeed above 6.0.12 so try to keep litespeed version 6.0.12 then when you are sure its litespeed 6.0.12 then open your favorite ssh client such as Putty/Bitvise SSH
/bin/bash /usr/local/lsws/admin/misc/enable_ruby_python_selector.sh
Second Step:
cagefsctl --force-update && cagefsctl -M
Now after completing this your app should work perfectly.
Disclaimer: Make sure you have backup of your server secondly if you face any issue then Kh Raad or its company is not responsible for any damage. I post articles after doing it in real life. We do not copy and paste tutorials all of our tutorials are tested.