At any given point in time, there is a single cache master server manager. By default, this master is initially selected through negotiation with other server managers. Generally, this is the server manager on the first cluster node that is started. After the cluster has selected a cache master, this server manager remains the cache master until it becomes unreachable. If this occurs, another server manager automatically becomes the master. After a switch in cache masters, if the previous master becomes reachable, it reverts to a cache slave status.