Standard Online Upgrade
To use a standard online upgrade, identify one or more nodes to remove from the cluster.
You must ensure that your cluster has adequate capacity to service requests with the remaining nodes while the identified nodes are upgraded.
|You cannot use the standard online upgrade process if your cluster does not have available capacity to service requests with at least one node removed.|
Because nodes must be rebalanced out of the cluster, upgraded, and rebalanced back into the cluster in a rolling fashion, the standard online upgrade is slower than the swap rebalance online upgrade strategy.
Couchbase recommends the swap rebalance online upgrade whenever possible because it maintains the cluster capacity always at a steady level throughout the upgrade. Use the standard online upgrade only if an upgrade with the swap rebalance is not possible.