Design And Imploementation Of IoT Middleware For Smart Door Lock

With the arrival of the third wave of information industry,the Internet of Things has emerged in all aspects of our lives.With the concept of "Experience China",proposed by Premier Wen Jiabao,the Internet of Things has become a hot topic,attracting the attention of the people of the country.Unlike the traditional Internet,the Internet of Things has brought a wide variety of items to the network.According to Gartner's statistics,the number of IoT devices in 2017 has exceeded the number of people in the world,which means that in this transition from the Internet to the Internet of Things era,the Realm of Things is at an imminent moment.After decades of development,the traditional Internet has formed a common norm in the industry,and the Internet of Things has not yet formed standards recognized in the field.If the massive multi-source heterogeneous data is handed over to the back-end server for processing in the traditional Internet industry,the hardware configuration requirements will be exaggerated,and it is not conducive to the horizontal vertical expansion of the server business.In order to solve this problem and ease the pressure on the background server,the concept of the Internet of Things middleware came into being.This article takes the Internet of Things middleware as the starting point,and discusses how to design a middleware with a full-featured,multi-transport protocol that can meet the production environment and can connect to a single server with millions of concurrent devices.Based on this,according to the actual situation.The project required the design of an IoT smart door lock system.At first,this article introduces the concept of middleware and its location in the project architecture,and introduces the main function of the Internet of Things middleware,that is,processing multi-source heterogeneous data.Then it discusses the topic of no unified transmission protocol standard in the industry,compares and analyzes the characteristics of MQTT protocol and CoAP protocol that need to be used in the project,designes comparative simulation experiments to test their performance,and make recommendations of which areas to use these protocols.Secondly,according to the main requirements of IoT middleware design,the feasibility of implementing high performance IoT middleware by Node.js is tested by a single server million-level concurrent connection experiment.Based on this,a smart door lock middleware system based on microservices is designed to provide basic functions such as service discovery,service registration and service upgrade including microservice architecture.It also includes MQTT,CoAP transport protocol data processing and system log.In addition,in order to alleviate the pressure of massive data on middleware,Kafka cluster is used as a "bridge" for information exchange between IoT middleware and baek-end server.Finally,the front-end management page,mobile app and back-end server of the smart door lock system are designed and implemented.The fragmentation function of the database MongoDB is used to persist the massive data,and realizes the docking of smart door lock middleware that is connected to a single million-level concurrent connection.