Role-based serializability for distributed object systems

In the role-based access control model, a role is a set of access rights. A subject doing jobs is granted roles showing the jobs in an enterprise. A transaction issued by a subject is associated with a subset of roles granted to the subject, which is named purpose. A method with a more significant purpose is performed before another method with a less significant purpose. We discuss which purpose is more significant than another purpose. We discuss two types of role-ordering (RO) schedulers SRO and PRO where multiple conflicting transactions are serializable in the significant order of subjects and purposes, respectively. We evaluate the RO schedulers compared with the traditional two-phase locking protocol in terms of throughput.