Policy Service for Distributed Systems

The ever-increasing size and complexity of large distributed systems makes management of such systems very difficult. This thesis describes a novel policy notation supported by a policy service which permits flexible evolution of the management system. Policies define the overall strategy of the management system and hence influence its behaviour. The policies are interpreted by management agents and so can be easily modified or changed without shutting down or reprogramming the agents. Obligation policies specify what activities a manager must perform, and authorisation policies specify what activities a manager is permitted to do. The policy service enables policies to be specified independent of the distributed agents which interpret them, thus enabling dynamic change of policies and reuse of these agents with different policies. Graphical tools are provided for specifying and interactively manipulating policies. The policy notation can be used to express both high-level (abstract) ..