Abstraction and composition techniques for reconfiguration of large-scale complex applications

Complex distributed applications are often developed incrementally while they are in active use. Programming and runtime environments must allow software designers to make these changes easily and efficiently. This must be provided within the appropriate framework for modeling, analysis and correct execution that is essential for complex applications. The key to supporting reconfiguration of large-scale applications is providing efficient abstraction and composition mechanisms. By separating specification of well-defined components from the component interaction and composition behavior, we allow designers to implement easily replaceable components and changeable interaction behavior. The abstraction mechanism simplifies development of large-scale reconfigurable applications by hiding implementation details. The facility also includes automatic analytical tools for checking consistency, reachability and dependency in the behavior of interacting components. These tools are essential for development and runtime support of large-scale and reconfigurable decentralized applications.