Using Transparent Shaping and Web Services to Support Self-Management of Composite Systems

Increasingly, software systems are constructed by composing multiple existing applications. The resulting complexity increases the need for self-management of the system. However, adding autonomic behavior to composite systems is difficult, especially when the existing components were not originally designed to support such interactions. Moreover, entangling the code for integrated self-management with the code for the business logic of the original applications may actually increase the complexity of the system, counter to the desired goal. In this paper, we propose a technique to enable self-managing behavior to be added to composite systems transparently, that is, without requiring manual modifications to the existing code. The technique uses transparent shaping, developed previously to enable dynamic adaptation in existing programs, to weave self-managing behavior into existing applications, which interact through Web services. A case study demonstrates the use of this technique to construct a fault-tolerant surveillance application from two existing applications, one developed in .NET and the other in CORBA, without the need to modify the source code of the original applications