Patent ID: 8850007
Filing Date: 2014-09-30
Classification: G06F

Abstract:
1. A method comprising: maintaining a cluster that includes cluster operational data and an independent replica that comprises a storage device that maintains the cluster operational data, that is not an element of any node of the cluster, that is not directly attached to the any node of the cluster, that is controlled by only one node of the cluster at a time, where the maintaining the cluster comprises the independent replica being exclusively controlled by the one node of the cluster based on the one node of the cluster obtaining or maintaining the exclusive control according to a node arbitration process that is configured for first reading a variable from the independent replica and, after a challenge period, second reading the variable from the independent replica, where the obtaining or the maintaining is based on the first reading and the second reading resulting in a same value, and where the independent replica is configured to be online in the cluster regardless of which of the any nodes are operational in the cluster.