Create a backup of your cluster data using cbbackup. See Section 7.8, “cbbackup Tool”.

Choose a node to remove from the cluster and upgrade. You can upgrade one node at a time, or if you have enough cluster capacity, two nodes at a time. We do not recommend that you remove more than two nodes at a time for this upgrade.

In Couchbase Web Console under Manage->Server Nodes screen, click Remove Server. This marks the server for removal from the cluster, but does not actually remove it.

Figure 2.5. Online Upgrade — Marking a Node for Removal from a Cluster

The Pending Rebalance shows servers that require a rebalance. Click the Rebalance button next to the node you will remove.

Figure 2.6. Online Upgrade — Starting the Rebalance Process

This will move data from the node to remaining nodes in cluster. Once rebalancing has been completed, the Server Nodes display should display only the remaining, active nodes in your cluster.

Figure 2.7. Online Upgrade — Cluster with the Node Removed

Perform an individual node upgrade to the latest version of Couchbase Server. See Section 2.6, “Upgrading Individual Nodes”.

Couchbase Server starts automatically after the upgrade. You now need to add the node back to the cluster.

Open Web Console for an existing node in the cluster.

Go to Manage->Server Nodes.

Click the Add Server button. You will see a prompt to add a node to the cluster.

At this point you can provide a hostname for the new node you add. For more information, see Section 2.4, “Using Hostnames with Couchbase Server”.

Figure 2.8. Online Upgrade — Adding the Node back to the Cluster

After you add the new node, the Pending Rebalance count will indicate that servers need to be rebalanced into the cluster.

Click Rebalance to rebalance the cluster and bring the new node into an active state.