Distributed information systems for decision-support and e-commerce applications require coordination of multiple autonomous components and their services to accomplish a set of global goals. In such systems, a global and often distributed coordination policy actively governs the coordination among the distributed components. The services provided and required by the components are coordinated according to the sequencing constraints specified by the policy.; Current architectures for such systems are based on design-time analysis to select a single coordination policy to implement over the application life cycle. A major problem with such a static configuration is handling dynamic changes in priorities, preferences and constraints of the autonomous components that require changes in the coordination policy. Short of bringing down and reconfiguring the system, current approaches can not switch coordination policies at run-time in response to dynamically changing conditions within a shared and often resource-constrained environment.; This dissertation presents the SWAP approach and architecture for handling such dynamic changes. SWAP is a self-adaptive software architecture containing change coordination mechanisms supporting run-time coordination policy changes. states and a change coordination agent that uses the tracked policy states to plan and implement change coordination actions. A major challenge confronted in the design of SWAP change coordination mechanisms is assuring dependable run-time policy changes that preserve application-specific safety and correctness properties for jobs undergoing processing during the change.; The major contribution of this dissertation is the development of the SWAP method for design and analysis of the configuration mechanisms that address the above challenge. The method specifies activities for the following: (1) Development of domain-specific architectures conforming to the SWAP architecture; (2) Systematic generation of tracking and change coordination agent specifications; (3) Verification via simulation that domain-specific safety and correctness properties are preserved during run-time changes.; To demonstrate, we use the SWAP method to develop domain-specific architectures and change coordination mechanism specifications for the view maintenance and workflow task domains. We then simulate the specifications using the SPIN model checker to verify their correctness.
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