In accordance with an embodiment, described herein is a system and method for supporting clustering in a multitenant application server environment. The system includes a domain with a plurality of server clusters, and a plurality of partitions, wherein each cluster is homogenously configured and targeted by one or more partitions. An application programming interface (API) can be used to initiate a resource group across-cluster migration within a partition. The API can invoke a replication manager, which queries a target cluster for a runtime topology for use in determining where to store primary session; migrates the primary session to a determined server instance in the target cluster. Additional clustering features, such as cluster messaging service, leasing service, singleton service management, session replication, clustered JNDI, and use of domain front-end load balancing, can be supported.