| It is often useful to distinguish between the definition of a core software system and features that may apply to it. A feature is an optional extension of the original system. Systems need to be adapted in order to take on new features. Distributed heterogeneous software is particularly hard to adapt for deployment in disparate execution environments. We introduce the concept of an adaptation service to coordinate crosscutting modifications to standard program components, transparently. This is achieved through Aspect-Oriented Programming. A service is made up of client- and server-side components called adaptlets. At run-time a protocol, GlueQoS, can be used to determine what adaptlets are activated. The goal is to reduce development costs associated with middleware application maintenance and deployment. |
