Building a Context World for Dynamic Service Composition

Dynamic service composition requires responding and adapting to changes in the computing environment when orchestrating existing services into one or more new services that fit better to a composite application. This paper abstracts the changes of the environment as a context world to store the physical contexts of the computing environment, user profiles and computed results of services as well. We use ontology techniques to model the domain concepts of application contexts. Context Condition/Effect Description Language is designed to describe the dynamic semantics of the requirements and capabilities of goals and services in a concise and editable manner. Goal-driven and planning techniques are used to dynamically implement the service composition according to the domain knowledge and facts in the context world.