Zero-downtime Internet process migration in same host

When I am running my website, something troubles me.  While there is a bug in the production server, I need to modify code and restart them.  Sounds fine, right? Yes, for most of web servers, they are stateless,  it is not a big deal to restart them whenever you want, but it is not true for me, they are realtime audio streaming servers. When you restart a realtime streaming server, it means audience connected to the server will be interrupted.  Here is a diagram shows the problem:

Good logging practice in Python

Introduce good logging practice in Python