4.7.x to 4.8.x Migration Guide

This is a minor HiveMQ upgrade. HiveMQ 4.8 is a drop in replacement for HiveMQ 4.7.x.
You can learn more about all the new features HiveMQ 4.8 provides in our release blogpost

HiveMQ 4.8 is prepackaged with all the HiveMQ Enterprise Extensions (disabled), the open-source MQTT CLI tool, and the HiveMQ Swarm load-testing tool (both located in the tools folder). If necessary, adapt your deployment pipeline to accommodate these changes.

Upgrade a HiveMQ Cluster

Rolling upgrades are supported and it is possible to run HiveMQ version 4.7 and version 4.8 simultaneously in the same cluster. By default, the HiveMQ cluster enables all new cluster features when all nodes are upgraded to the new version. No manual intervention is required.

Please follow the instructions in our user guide to ensure a seamless and successful rolling upgrade.

For more information, see HiveMQ Clustering Documentation.

Upgrade a Single-node HiveMQ Instance

  • Create a backup of the entire HiveMQ 4.7.x installation folder from which you want to migrate

  • Install HiveMQ 4.8 as described in the HiveMQ Installation Guide

  • Migrate the contents of the configuration file from your old HiveMQ 4.7.x installation

  • To migrate your persistent data, copy everything from the data folder of your backup to the data folder of the new HiveMQ 4.8 installation. The first time you start HiveMQ 4.8, the file storage formats of the persistent data from your previous installation are automatically updated in the new persistent storage.

Configuration File Changes

You can upgrade from HiveMQ 4.7.x to HiveMQ 4.8 without making changes to your configuration file.

Persistent Data Migration

When you migrate, HiveMQ 4.8 automatically updates the file storage formats of all the data that you copied into your new data folder.

To migrate the persistent data, you must copy everything in the data folder of the previous HiveMQ 4.7.x installation to the data folder of your new HiveMQ 4.8 installation.

Linux example
cp -r /opt/hivemq-4.7.6/data/* /opt/hivemq-4.8.0/data/

The first time you start HiveMQ 4.8, the file storage formats of the persistent data from your previous installation are automatically updated in the new persistent storage.

Native SSL Default Communication Protocols

Due to security concerns, the OpenJDK Java platform no longer enables TLSv1 and TLSv1.1 by default. As a result, Java applications such as HiveMQ that use TLS to communicate now require TLS 1.2 or above to establish a connection.

To align with the OpenJDK Java platform, from HiveMQ 4.7 onwards, HiveMQ only enables the following TLS protocols by default for native SSL:

  • TLSv1.3

  • TLSv1.2

If you still need to support legacy TLS versions such as TLSv1 or TLSv1.1 for your Native SSL implementation, you must explicitly enable the versions in your tls-tcp-listener configuration. For more information, see Communication Protocol and Native SSL.
Example configuration for native SSL with explicit legacy TLS configuration
<?xml version="1.0"?>
<hivemq xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

    ...
    <listeners>
        ...
        <tls-tcp-listener>
            <tls>
                ...
                <!-- Enable specific TLS versions manually -->
                <protocols>
                    <protocol>TLSv1.1</protocol>
                </protocols>
                <native-ssl>true</native-ssl>
                ...
            </tls>
        </tls-tcp-listener>
    </listeners>
    ...
</hivemq>

HiveMQ Bridge Extension

The most significant changes in this release include the following:

  • To further secure your deployment, the HiveMQ Enterprise Bridge Extension now enables loop-prevention with hop-count-limit=1 by default.

The new setting prevents infinite loops in configurations where two MQTT 5 Brokers are connected via the Bridge Extension.

  • If your topology features exactly two MQTT Brokers, no further action is required.

  • If your topology includes more than 2 MQTT Brokers, you must adapt your hop-count-limit. Example: You have 3 Brokers (Broker A, Broker B, Broker C) and want messages published to Broker A to be forwarded from Broker A to Broker B and then Broker C, For this use case, you need to set the hop-count-limit to a value of 2.

For more information, see Loop prevention.