You can add a failed over node back to the cluster if you identify and fix the issue that caused node failure. After Couchbase Server marks a node as failed over, the data on disk at the node will remain. A failed over node will not longer be synchronized with the rest of the cluster; this means the node will no longer handle data request or receive replicated data.
When you add a failed over node back into a cluster, the cluster will treat it as if it is a new node. The means that you should rebalance after you add the node to the cluster. This also means that any data stored on disk at that node will be destroyed when you perform this rebalance.
Copy or Delete Data Files before Rejoining Cluster
Therefore, before you add a failed over node back to the cluster, it is best practice to move or delete the persisted data files before you add the node back into the cluster. If you want to keep the files you can copy or move the files to another location such as another disk or EBS volume. When you add a node back into the cluster and then rebalance, data files will be deleted, recreated and repopulated.
For more information on adding a node to the cluster and rebalancing, see Section 5.7.2, “Performing a Rebalance”.