Real-Time Systems CSE 520 WUSTL: Message Brokers

AN ISO standard (ISO/IEC PRF 20922)[2] publish-subscribe-based "lightweight" messaging protocol for use on top of the TCP/IP protocol. It is designed for connections with remote locations where a "small code footprint" is required or the network bandwidth is limited.

methods (sometimes referred to as verbs) to indicate the desired action to be performed on the identified resource.

• Connect
• Disconnect
• Subscribe
• UnSubscribe
• Publish

Method that waits for a connection to be established with the server.

Method that waits for the MQTT client to finish any work it must do, and for the TCP/IP session to disconnect.

Method that waits for completion of the Subscribe or Unsubscribe method.

Method that requests the server unsubscribe the client from one or more topics.

Method that returns immediately to the application thread after passing the request to the MQTT client.