MQTT (Message Queuing Telemetry Transport) has become the perfect messaging protocol for IoT (Internet of Things) systems since it is the lightest protocol designed for low bandwidth, high-latency, unreliable networks. Today, the strategy of distributing several MQTT brokers on the networks is widely used because the strategy of using a single broker is no longer efficient. However, in the distributing architectures of MQTT brokers, a subscriber should have prior knowledge about the address of the broker that publishes the data on the topics of interest. In this paper, we tackle this challenge by proposing a mechanism that connects the subscribers to the brokers in a transparent way. The proposed approach, known as TD-MQTT (Transparent Distributed MQTT brokers), requires no prior knowledge of the brokers by the subscribers. The data will be carried automatically from brokers that can change their configuration and location. The transparency will help to use IoT data without worrying about their location and dynamic configuration changes. To evaluate our approach, we compared it with the basic distributed MQTT and the EMMA (MQTT Middle-ware for Edge Computing Applications) approach. The results of the evaluation show that TD-MQTT is much better than the standard MQTT, especially in terms of response time.

翻译：MQTT（消息队列遥测传输）已成为物联网系统理想的通信协议，因其专为低带宽、高延迟、不可靠网络设计的轻量级特性。当前，在网络上部署多个MQTT代理的策略已被广泛采用，因为单代理模式已不再高效。然而，在MQTT代理的分布式架构中，订阅者需预先知晓发布其感兴趣主题数据的代理地址。本文提出一种透明连接订阅者与代理的机制来解决该挑战。所提出的方法称为TD-MQTT（透明分布式MQTT代理），无需订阅者预先知晓代理信息。数据将自动从可动态配置和迁移的代理中获取。这种透明性有助于在无需关注数据位置和动态配置变化的情况下使用物联网数据。为评估本方法，我们将其与基础分布式MQTT及EMMA（面向边缘计算应用的MQTT中间件）方法进行了对比。评估结果表明，TD-MQTT在响应时间等方面显著优于标准MQTT。