Managing Stale Websocket Connections

[kmiklas]

Note: Also documented on SO here:
https://stackoverflow.com/questions/63639414/how-to-manage-stale-websocket-connections]

Using Python Websockets [1] to manage a set of server-side websocket connections from browser. They must be registered and maintained.

Problem: when User disconnects a stale connection remains present in the registry. Also, if user refreshes browser (1, 2, 17... or n times), or a reconnect script is present, more invalid connections are registered. This creates a big registry of stale connections.

The docs address this issue as follows:

As shown in the synchronization example above, if you need to maintain
a list of currently connected clients, you must register them when
they connect and unregister them when they disconnect.

How are stale connections properly identified and removed? Is some sort of ping/pong scheme required?

I did find the code in [2], but it goes back to 2018. Is this obsolete, or has this issue since been addressed?

Ref:

1. https://websockets.readthedocs.io/en/stable/intro.html
2. Common pattern for reconnections #414

[aaugustin]

The example here (https://websockets.readthedocs.io/en/stable/intro.html#registration) removes stale connections:

    finally:
        # Unregister.
        connected.remove(websocket)