How many physical servers are needed to create a minimum Cluster configuration?
The recommendation for good redundancy would be 2 MySQL Server Nodes, 2 Data Nodes and 1 Management Node. For evaluation purposes it is possible to have only a single physical server, but that would only serve as a very basic evaluation. The minimum fully fault tolerant solution would consist of 3 servers with the 2 data nodes and the management node all running on different hosts and with at least 2 MySQL Server nodes running on different hosts from each other.