Since upgrades of both of them happen regularly, we have implemented a feature to update your cluster as far as possible with just the click of a button.
The new upgrade feature is located under Nodes information, where the usual upgrade options are. As shown in the image below, the feature will tell you how far it can take your nodes. There are certain versions that must be stopped for RabbitMQ to carry out necessary migrations (see the Official RabbitMQ Version Upgradability table) so if it’s not possible to get to the latest version right away, there might be a need for multiple updates.
If either RabbitMQ or Erlang is already upgraded to the latest possible version, the feature will be disabled, and the usual upgrade method should be used. This is a precaution so that the upgrade can be a rolling upgrade with zero downtime (only applies to patch version upgrades of RabbitMQ), if possible.
An upgrade of Erlang will always cause some downtime to your cluster (or single node). That will also be the case for this upgrade. Read more about RabbitMQ and Erlang upgrades.
We hope this will be an appreciated feature. Let us know if you have any questions!
All the best,
/Johan and the CloudAMQP team