Frameworks for Distributed Object-Oriented Computing (ObjectWire)

Distributed computing needs high-level, procedure-call-like interfaces that hide much of the complexity inherent to distribution. But as experience shows (e.g., with existing CORBA-based implementations), high-level interfaces are not enough. In addition, control over implementations decisions (affecting performance or other system qualities) as well as communication primitives on different levels of abstraction and support for analyzing and configuring a system are needed. In this project we developed an infrastructure for distributed object-oriented applications and concentrated on the issues mentioned above. ObjectWire is a framework-based environment that allows the adaptation of various implementation decisions. The environment has a layered architecture and offers communication interfaces on different levels of abstraction. In addition, it provides a flexible architecture for integrating monitoring tools and offers basic services for configuration, group communication, and object transport. A replication mechanism was added in the construction of an environment supporting co-operative software development. The configuration and monitoring capabilities of ObjectWire were further extended in the OrWell project. The environment has been used for investigating framework construction and for experimenting with different distributed object-oriented architectures.