Failing over nodes

Failing over nodes

Failover is the process in which a node in a cluster is declared as unavailable and a replica vBucket is enabled.

Information is distributed around a cluster using a series of replicas , which are complete copies of the data stored in the bucket and kept within the Couchbase Server Cluster. For Couchbase buckets, you can configure a number of replicas.

In the event of a failure in the server (either due to transient failure or for administrative purposes), use a process called failover to indicate that a specific node within the cluster is no longer available and to enable the replica vBuckets for the failed over node.

The failover process contacts each server that was acting as a replica and updates the internal table that maps client requests for documents to an available Couchbase Server.

Failover can be performed manually or automatically using the built-in automatic failover process. Auto failover acts after a preset time, when a node in the cluster becomes unavailable.