Please note this group is for discussions of the MQTT protocol in
general (I think that's what people say here ... :-)
Other than that:
> 1) Is there a way to view ALL 'retained' message on Mosquitto broker?
Subscribe to '#'; if you're not hindered by ACLs, you'll get them all.
> 2) What is the command to clear all or part of the 'retained messages?
Publish a retained, NULL payload to a topic.
-JP