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node.jsmqttmosca

How to delete publish message of MQTT protocol in node js

developing chat application using MQTT protocol, mosca (node module) and MongoDB as a database in Node.js

facing the problem of how to delete publish message and remove from all subscriber in app.

Solution

  • At a MQTT level you can't, once a message has been published it's will be delivered by the broker to all connected clients (and queued for disconnected clients) with a matching subscription.

    The only thing that is possible is to clear a retained message to prevent the same payload being re-delivered each time the client connects. You do this by publishing a message with a null payload (and the retained bit set)

    If you want to delete messages at the chat level you will have to implement this yourself with in the application.