Research And Implementation Of Distributed MQTT Protocol

The MQTT(Message Queuing Telemetry TransPort)protocol is an Internet of Things protocol[1]launched by IBM.Due to its streamlined and lightweight features,it occupies a mainstream position in the Internet of Things field.With the continuous development of the Internet of Things,the MQTT protocol has broader application scenarios,such as:applying the MQTT protocol to live video barrage transmission on the computer or mobile terminal,communication between drone clusters or small robot clusters,etc[2].In some small Internet of Things systems,the MQTT protocol with a single Broker structure is used to realize the process of sending and receiving messages,but this centralized structure has bottlenecks and deficiencies.Broker node failure failure will lead to the collapse of the entire system,that is,a single point of failure.Aiming at the single point of failure problem,this thesis analyzes the distributed architecture of Data Distribution Service(DDS),combines the"Global Data Space" of DDS with the MQTT protocol,and proposes a distributed extension method of the MQTT protocol,thus Effectively solve the single point failure problem of the MQTT protocol.At the same time,by analyzing the existing load balancing scheme,this thesis proposes a load balancing strategy in a small IoT system with only two nodes,Client and Broker.Mutual selection with Broker nodes to achieve load balancing.Finally,this thesis designs and implements a distributed MQTT protocol system based on Mosquitto.After actual deployment and testing,the MQTT protocol system implemented based on the global data space provides the function of MQTT nodes publishing/subscribing messages in a distributed scenario,which effectively solves the problem of single-point failure in the MQTT protocol.At the same time,in a multi-Broker scenario,the load balancing strategy proposed in this thesis can also achieve a relatively uniform load effect.The realization of the distributed MQTT protocol is an exploration of the development of distributed protocols in the field of Internet of Things,and has positive significance for the expansion of distributed systems in the field of Internet of Things.