You can configure data replication for each bucket in cluster. You can also configure different buckets to have different levels of data replication, depending how many copies of your data you need. For the highest level of data redundancy and availability, you can specify that a data bucket will be replicated three times within the cluster.
Replication is enabled once the number of nodes in your cluster meets the number of replicas you specify. For example, if you configure three replicas for a data bucket, replication will only be enabled once you have four nodes in the cluster.
After you specify the number of replicas you want for a bucket and then create the bucket, you cannot change this value. Therefore be certain you specify the number of replicas you truly want.
For more information about creating and editing buckets, or specifying replicas for buckets, see Section 6.3.1, “Creating and Editing Data Buckets”.