When one or more nodes have been brought into or taken out of a cluster, rebalance redistributes data and indexes among available nodes. Rebalance can be performed and configured by means of the REST API.
REST Rebalance Overview
Rebalance must be performed whenever the number of nodes in a cluster have changed, and whenever buckets have been added or removed. A complete overview is provided in Rebalance.
The REST API supports the following:
Rebalancing the Cluster. Rebalance can be performed; specifying all current cluster-nodes, and specifying which (if any) are to be ejected.
Getting Rebalance Progress. The progress of an ongoing rebalance to be ascertained.
Configuring Rebalance Retries. Rebalance failures can be responded to automatically, with up to 3 retries. The number of seconds required to elapse between retries can also be configured.
Getting Rebalance-Retry Status. The status of pending rebalance retries can be returned.
Canceling Rebalance Retries. Rebalance retries can be canceled.
Limiting Concurrent vBucket Moves. The number of concurrent moves of vBuckets that occur during rebalance can be limited, with the limit applied to every node in the cluster; so as to increase rebalance performance.