Policy Based Self-Management in Distributed Environments

Currently, increasing costs and escalating complexities are primary issues in the distributed system management. The policy based management is introduced to simplify the management and reduce the overhead, by setting up policies to govern system behaviors. Policies are sets of rules that govern the system behaviors and reflect the business goals or system management objectives. This paper presents a generic policy-based management framework which has been integrated into an existing distributed component management system, called Niche, that enables and supports self-management. In this framework, programmers can set up more than one Policy-Manager-Group to avoid centralized policy decision making which could become a performance bottleneck. Furthermore, the size of a Policy-Manager-Group, i.e. the number of Policy-Managers in the group, depends on their load, i.e. the number of requests per time unit. In order to achieve good load balancing, a policy request is delivered to one of the policy managers in the group randomly chosen on the fly. A prototype of the framework is presented and two generic policy languages (policy engines and corresponding APIs), namely SPL and XACML, are evaluated using a self-managing file storage application as a case study.