Conflict Resolution on Policy Management

The simple event-condition-action (ECA) rule paradigm of active databases has proved very useful in many Al and database applications. However, its applicability goes beyond data management. ECA rules can be used in network management and monitoring, electronic commerce, security and access management, and other application areas to express policies - collections of general principles specifying the desired behavior of a system. In this paper we use a declarative policy description language PDL, in which policies are formulated as sets of ECA rules. The main contriobution of the paper is a framework for detecting action conflicts and finding resolutions to these conflicts. Conflicts are captured as violations of action constraints. The semantics of rules, and conflect detection and resolution are defined axiomatically using logic programs. Given a policy and a set of action contraints the framework defines a range of monitors that filter the output of the policy to saftisy the constraints. We present algorithms to compute the monitors and analyze their computational complexity. We briefly describe the architecture of a PDL-based policy server beign used to provide centralized administration of a soft switch in a communication network and show how it can be augmented to handle conflict resoltion.