Chapter 1. Lightweight Messaging with MQTT 3.1.1 and Mosquitto
In this chapter, we will start our journey towards the usage of the preferred IoT publish-subscribe lightweight messaging protocol in diverse IoT solutions combined with mobile apps and web applications. We will learn how MQTT and its lightweight messaging system work. We will learn MQTT basics, the specific vocabulary for MQTT, and its working modes. We will use different utilities and diagrams to understand the most important concepts related to MQTT. We will:
- Understand convenient scenarios for the MQTT protocol
- Work with the publish-subscribe pattern
- Work with message filtering
- Learn basic concepts related to MQTT
- Understand the MQTT puzzle: clients, servers or brokers, and connections
- Install a Mosquitto MQTT server on Linux, macOS, or Windows
- Publish messages
- Subscribe to topics
- Unsubscribe from topics
- Work with best practices when creating topics
- Understand wildcards
- Learn about the different Quality of Service levels
- Work with at least once delivery
- Work with exactly once delivery