| A policy is defined as any type of formal behavioural guide [43] that is input to the system. A policy set can be understood to represent a strategy for achieving a set of objectives. The strategy-tree is an abstraction that encapsulates and relates multiple strategies for achieving a set of objectives over time. Evaluation of a given strategy's performance against administrator specified expectations is made on multiple time-scales and decisions to alternate among the set of strategies are made at defined intervals. This dynamic approach to policy-based management has implications in the general area of distributed system's management.;Keywords: data center, management, middleware, objectives, policy, service level agreement (SLA), strategy-tree;This thesis introduces the concept of the strategy-tree. It presents a formal model along with the requisite algorithms for providing the management capabilities at runtime. Further, an architecture is described and prototype implementation developed which facilitates the design and creation of a strategy-tree as well as its use in experimentation. The results of the various experiments demonstrate the effectiveness of this approach in achieving various sets of objectives including a pair that are in conflict. |
