A model for dynamic configuration which preserves application integrity

Our approach to dynamic configuration is based on building a model of reconfigurable applications. The model documents applications according to the configuration paradigm and for each component, captures structural constraints and behavioural information. The model presents change administrators with an abstract interface to dynamic configuration management. Change is initiated by submitting a version descriptor to the configuration manager; much of the low-level and error-prone activities of dynamic configuration are automated. Synchronisation of dynamic configuration with the application and management of persistent state are fundamental to preserving an application's integrity. We present our synchronisation mechanism, which adopts atomic operations for both intra- and inter-component computation. The problems of persistent state management are simplified by our synchronisation model. We also expose the difficulties and propose solutions for managing composite components and components whose operations are constrained.