That error is produced when requests exceed the NGINX uwsgi_read_timeout setting. After NGINX exceeds this limit it closes the socket and then uWSGI tries to write to the closed socket, producing the error that you see from uWSIG.
Make sure your NGINX timeouts are at least as high as uWSGI timeouts (HARAKIRI_TIMEOUT).
syntax not correct, use like this:
- Django – When should I use signals and when should I override save method?
- Why isn't my Django User Model's Password Hashed?