A computer system for hosting computing clusters for clients. The system includes clusters each including a set of computing resources and each implemented in custom or differing configurations. Each of the configurations provides a customized computing environment for performing particular client tasks. The configurations may differ due to configuration of the processing nodes, the data storage, or the private cluster network or its connections. The system includes a monitoring system that monitors the clusters for operational problems on a cluster level and also on a per-node basis such as with monitors provided for each node. The system controls client access to the clusters via a public communications by only allowing clients to access their assigned cluster or the cluster configured per their specifications and performing their computing task. Gateway mechanisms isolate each cluster such that communications within a cluster or on a private cluster communications network are maintained separate.