You should use the same version number when you perform the migration process to prevent version differences which may result in a failed upgrade. To upgrade between Couchbase Server Community Edition and Couchbase Server Enterprise Edition, you can use two methods:
Perform an online upgrade
Here you remove one or more nodes from the cluster and rebalance. On the nodes you have taken out of the cluster, uninstall Couchbase Server Community Edition package, and install Couchbase Server Enterprise Edition. You can then add the new nodes back to the cluster and rebalance. This process can be repeated until the entire cluster is using the Enterprise Edition.
For more information on performing online upgrades, see Section 2.5.1, “Online Upgrades”.
Perform an offline upgrade
Here you need to shutdown the entire cluster, and uninstall Couchbase Server Community Edition, and install Couchbase Server Enterprise Edition. The data files will be retained, and the cluster can be restarted.
For more information on performing offline upgrades, see Section 2.5.3, “Offline Upgrade Process”.