During a server rebalance, Couchbase Server automatically updates information about where data is located. During the rebalance, a Couchbase SDK can therefore still write to an active node in a cluster and the Couchbase Server will update information about the newly saved data location. Once the rebalance is complete, your Couchbase SDK will automatically switch to the new topology. For more information, see Couchbase Server Manual 2.0, Rebalancing