A compliant persistent architecture

The changing needs of modern application systems demand new and radical sof tware architectures to support them. The attraction of persistent systems i s that they define precisely the extent to which they are open, thereby all owing the dynamically changing resource requirements of applications to be tracked accurately within the persistent environment. Thus, an ever-growing body of work is being established to study the nature of running applicati ons, and to use the information gleaned, to improve the runtime execution o f these applications. Here we propose a new architectural approach to const ructing persistent systems that accommodates, and thus is compliant to, the needs of particular applications. By separating policy from mechanism in a ll components, the architecture may be tailored to the policy needs of the application. We first propose a generic architecture for compliance, and th en show how it may be instantiated, Finally, we describe an example of how the architecture operates in a manner that is compliant to a target applica tion, me postulate, since we have not yet measured, that the benefits of co mpliant architectures will be a reduction in complexity, with corresponding gains in flexibility, portability, understandability in terms of failure s emantics, and performance. Copyright (C) 2000 John Wiley & Sons, Ltd.