How to know who subscribes to a TOPIC?

Hello guys,
I am trying to list all the subscribers who subscribe to a Topic.
The purpose is to log and monitor a Topic, see if the clients receive the message or not.
I know we can use HiveMQ API to * List all MQTT Clients, or * List all subscriptions for a specific MQTT client
Looks like they can monitor a specific Client, but can’t monitor a specific Topic


Hi @yifan,

the only way currently is to create an extension that collects the subscribers of a subscription via SubscriptionStore.iterateAllSubscribersForTopic and create a custom rest service (using Jetty Server or something similar) in the extension to expose this information.

Hope this helps.

Michael from the HiveMQ team