Question

The MQTT publish-subscribe protocol is:
a. Event driven
b. Broker driven
c. Client driven
d. All of these

Answer 1

d. All of these.

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Answer 2

Publish–subscribe: A messaging pattern where publishers don't send the messages directly to the subscribers.

They configure in such a way that it categorizes published messages into classes.

These classes are used by the subscribers.

This is not known to the subscribers.

It decouples the sender and the receiver.

The clients connect and communicate with a server called as the broker.  

The broker provides the messaging patterns required for communication between the client and the server in the publish subscribe system.

Hence, MQTT protocol is event driven, client driven and also broker driven.

The answer is (d) All of these.