How to Delete MQTT Retained Messages on Subtopics Recursively
By default, every MQTT topic can have a retained message. The standard MQTT mechanism to clean up retained messages is sending a retained message with an empty payload to a topic. This will remove the retained message.
However, sometimes you just want to delete all retained messages for a topic tree, recursively. This is now possible with the Delete Retained Messages Recursively Plugin.
Retained Message Store Service API
Even if this plugin itself isn’t useful for you, this is a perfect starting point for studying the Retained Message Store Service API for your own plugins. With HiveMQ, it’s a piece of cake to add, delete and modify the retained messages on topics. If you want to take a look at the source code, the code is available on Github.
UPDATE: Kindly note, this plugin was supported by HiveMQ 3.X versions, however, not for HiveMQ 4.X versions. Contact us to get clarification if you are looking for this feature
HiveMQ Team
The HiveMQ team loves writing about MQTT, Sparkplug, Industrial IoT, protocols, how to deploy our platform, and more. We focus on industries ranging from energy, to transportation and logistics, to automotive manufacturing. Our experts are here to help, contact us with any questions.
