One harsh truth we discover while building backend systems for IoT devices like industrial sensors or electric vehicle (EV) chargers is this: Hardware lies. Your Python WebSocket server works flawlessly on your local machine, but deploy it to production where physical hardware is shoved into underground concrete parking garages, fighting high-voltage electromagnetic interference, and constantly falling back to legacy 2G/3G networks, and your server will quickly fall victim to "Zombie Connections."
I still remember a seminar I attended where a gentleman was explaining how he had deployed their IoT devices on generators in remote mining locations. They were facing this exact issue. The IoT devices were sending all-green signals, but the physical generators were completely offline.
A Zombie Connection happens when an IoT device loses cellular service and drops off the network abruptly, failing to send a standard TCP close frame. The Python server still considers it an open connection.
The Naive (and Dangerous) Approach
Most Python WebSocket tutorials teach you to handle connections like this:
