Dynamic Introduction of Attributes into Policies

Current techniques in the field of policy management rely on system designers and implementers ‘baking’ information about policies and the attributes that those policies can have and what those attributes mean into a system at design and build time. In the future, in which policydriven dynamic techniques for systems management and system composition become widespread (initiatives in this area include Autonomic Computing [6,7] and On Demand Computing [8]), this design- and build-time approach will no longer be suitable—a dynamic system must, in order to be effective, have a dynamic understanding of the policies, and the attributes of those policies, which drive it.

We describe a step on the road to a policydriven, dynamic IT world—specifically, we describe techniques by which (for example) a hardware upgrade or a small change in a user’s requirements can have an effect on a system without requiring a change in the policies, or the policy infrastructure. Our technique permits new attributes to be defined within existing policies, without changes to the supporting policy evaluation and management code. As a concrete example, we further describe how the ability to introduce new attributes can be implemented as part of a policy-based storage management system.