Date of Original Version
Abstract or Description
Dynamic change management in an autonomic, service-oriented infrastructure is likely to disrupt the critical services delivered by the infrastructure. Furthermore, change management must accommodate complex real-world systems, where dependability and performance objectives are managed across multiple distributed service components. This paper presents a change management framework that enables the assessment and minimization of service delivery disruptions. The framework builds on a few general principles. First, change management systems handle both external change requests, like software upgrades, and changes to mitigate internal events, like faults. Second, the impact on service delivery is assessed as the impact on the business values of the performance and dependability objectives across all services. The goal is to schedule change operations in order to maximize the business value across all service objectives over a long time horizon. These principles are achieved with a distributed design: change operation scheduling and business value optimization are performed by an orchestrator, while the impact assessment on specific objectives is distributed to objective-specific modules that employ domain-specific models for estimation and prediction.