When in a cluster, EMQX nodes can be upgraded one at a time without any downtime. This process is referred to as a rolling upgrade. To achieve smooth client session migration, you can make use of the cluster rebalancing feature to evacuate clients from a node before upgrading it. Find more information about cluster rebalancing here.
The rolling upgrade process for each node in the cluster is as follows:
- Evacuate clients from the node using cluster rebalancing. (optional)
- Stop the old version node.
- Backup the config files and data directory of the nodes.
- Install a new version of EMQX.
- Start the new version node.
Do not perform cluster-wide config changes during a rolling upgrade. Configuration changes made from Dashboard, HTTP API, or CLI are applied to all nodes in the cluster. Making configuration changes during a rolling upgrade may cause nodes to become out of sync.
RPM and DEB
When using RPM or DEB packages, you can upgrade EMQX by simply installing the newer version package.
When using Docker, you can upgrade EMQX by simply pulling the newer version image and restarting the container.
Upgrade from Open Source to Enterprise Edition
If you are running an Open Source version of EMQX and would like to upgrade to the Enterprise Edition, the process is the same as upgrading to a newer version of the Open Source Edition.
There is no difference between the Open Source and Enterprise Editions of EMQX in terms of installation and upgrade. The only caveat is that you need to manually configure your license in
emqx.conf for the Enterprise edition nodes after each upgrade, but cannot apply the license key to the whole cluster before all nodes are upgraded.
For example, add the following line to
license.key = "your license"
If a license configuration is added to
emqx.conf, any runtime changes made from the Dashboard, HTTP API, or CLI will be lost after the node is restarted. This is because
emqx.conf and environment variables have the highest priority when loading configurations during startup.