What is split brain syndrome?
Split brain syndrome, in the context of high-availability clusters, refers to a situation where the nodes in a cluster lose communication with each other, and each node perceives itself as the only surviving member of the cluster. This can lead to conflicting actions being taken by different nodes, potentially causing data corruption, service disruptions, or other serious issues.

In a clustered environment, nodes communicate with each other to coordinate and make joint decisions about the state of the cluster. When communication between nodes is lost due to network issues or other failures, and no mechanism is in place to prevent nodes from operating independently, split brain syndrome can occur

To avoid split brain syndrome, high-availability clusters typically employ mechanisms such as quorum, fencing, and heartbeat mechanisms