[MQTT] HowTo Delete Subscriptions?

After deleting a MQTT Generic Thing and recreating a new one using a different Broker Thing, the Thing is working correctly, however the system still is subscribed to the former topics via the old Broker Thing.
Raising the log:level of org.openhab.core does show WARN messages like:

2021-02-16 13:22:29.237 [DEBUG] [.thing.internal.CommunicationManager] - Received event '98' for non-existing thing 'mqtt:topic:opuspi3MQTTBroker:Rolladen_Wohnzimmer_Thing', not forwarding it to the handler
Actual Identifier: mqtt:topic:opuspi4MQTTBroker:Rolladen_Wohnzimmer_Thing

HowTo delete such subscriptions?
Restart openHAB, System Restart, stopping Mosquitto and deleting the mosquitto.db did not help.

The old Things are for sure gone? Double check using the REST API Docs or grepping through the JSONDB files.

If they are gone I’m at a loss. The best I can offer is to file an issue. If they are still hanging around then we can figure out how to get rid of them.

I checked the REST API.
I’ll file an issue on that one.

Opened a Issue, did some deeper search (this time not only the JSON-DB for Things but also for the Links).
Found SEVERAL stale Links, removed them and the problem is gone!


I would have suggested that before but I never imagined that just the Links would keep the MQTT subscriptions active. Good find!

If only I would have come to this idea before… :roll_eyes:

Although I have removed a large number of stray links now, the original reason to raise the log-level of org.openhab.core however isn’t solved! (Why am I getting Attempting to send a state update of an item which doesn't exist: undefined whenever displaying the sonos-widget)