Managing the Evolution of Distributed and Interrelated Components

Abstract

Software systems are increasingly being built by integrating preexisting components developed by different, geographically distributed organizations. Each component typically evolves independently over time, not only in terms of its functionality, but also in terms of its exposed interfaces and dependencies on other components. Given that those other components may also evolve, creating an application by assembling sets of components typically involves managing a complex web of evolving dependencies. Traditional configuration management systems assume a form of centralized control that simply does not suffice in these situations. Needed are new configuration management systems that span multiple organizations, operate in a distributed and decentralized fashion, and help in managing the consistent evolution of independently developed, inter-related sets of components. A critical aspect of these new configuration management systems is that they must respect the different levels of autonomy, privacy, and trust that exist among different organizations. In this paper, we introduce TWICS, an early example of such a new configuration management system. Key aspects of TWICS are that it maintains traditional configuration management functionality to support the development of individual components, but integrates policy-driven deployment functionality to support different organizations in evolving their inter-related components.