Preventing data corruption due to pre-existing split brain

A non-transitory computer readable storage medium storing program instructions executable for:

• in response to determining that a node is no longer part of a sub-cluster of a cluster,
• designating another node in the sub-cluster as a racer node;
• accessing a matrix, wherein
• the matrix comprises information to determine whether a majority of a plurality of coordination points in the cluster are accessible during a fence race by a plurality of nodes in the sub-cluster, wherein each of the coordination points can fence off one or more nodes in the cluster from accessing one or more storage devices, and
• the plurality of coordination points comprise an odd number of coordination points;
• based on the accessing, determining that the information indicates that the majority of the plurality of coordination points are accessible by the plurality of nodes;
• and
• broadcasting the information.

A system comprising:

• one or more processors;
• and
• a memory coupled to the one or more processors, wherein the memory stores program instructions executable by the one or more processors for:
• in response to determining that a node is no longer part of a sub-cluster of a cluster,
• designating another node in the sub-cluster as a racer node;
• the racer node accessing a matrix, wherein
• the matrix comprises information to determine whether a majority of a plurality of coordination points in the cluster are accessible during a fence race by a plurality of nodes in the sub-cluster, wherein each of the coordination points can fence off one or more nodes in the cluster from accessing one or more storage devices, and
• the plurality of coordination points comprise an odd number of coordination points;
• based on the accessing, determining that the information indicates that the majority of the plurality of coordination points are accessible by the plurality of nodes;
• and
• broadcasting the information.