How to "Bridge" or "Daisy-Chain-Cluster" HiveMQ Brokers


I want to set up a 3-broker-cluster/bridge with one of the brokers being the “middle man” in a star-topology so to speak.
The setup should be, having broker A as the center of the star:

I tried clustering the three with a static discovery config but I only get a connection between two of the brokers. the third one is then not able to join the cluster. My conclusion is that the third broker trying to connect to the cluster always tries to connect to all brokers that are part of the cluster. In the config of B and C, I only have configured the IP address of A as the static cluster partner.

I do not want to set up a HA MQTT cluster but extend the reach of the availability through different firewall zones.

How can I configure the cluster to “daisy chain” instead of building a connection between all cluster nodes for HA?
In HiveMQ Version 2 there was something lice a bridging announced instead of clustering, which seems to be what I am looking for.

One problem is that the Cluster is set up in a larger network environment and I only have a firewall allowance rule for the connection

Hi @Chester,

You are totally correct in assuming, that the HiveMQ cluster feature is mainly for HA and performance. As it uses a masterless topology it is not possible to use the clustering to create a daisy chain. Each node must be able to exchange data with every other node. (So firewall rules won’t help here)

The best way to implement your setup is by bridging, as you rightly stated.

The HiveMQ team is currently working on a new Enterprise Bridge Extension, that will address this issue and should be a perfect match for your use case. The initial release of the Bridge extension should not be too far in the future.

If you are interested please contract

A wish you a great week


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