Component technology promotes code-reuse by enabling the construction of complex applications by assembling of-the-shelf components. However, components depend on certain characteristics of the environment in which they execute. They depend on other software components and on hardware resources. In existing component architectures, the application developer is left with the task of resolving those dependencies, i.e., making sure that each component has access to all the resources it needs and that all the required components are loaded. Nevertheless, according to encapsulation principles, developers should not be aware of the component internals. Thus, it may be dicult to fi nd out what a component really needs. In complex systems, this manual approach to dependency management can lead to disastrous results. In this paper, we propose an integrated architecture for managing dependencies in distributed component-based systems in an efective and uniform way. The architecture supports automatic configuration and dynamic resource management in distributed heterogeneous environments. We describe a concrete implementation of this architecture and present experimental results.

Abstract. Rapid advances in networking, hardware, and middleware technologies are facilitating the development and deployment of complex grid applications, such as large-scale distributed collaborative scientific simulation, analysis of experiments in elementary particle physics, distributed mission training and virtual surgery for medical instruction. These predominantly collaborative applications are characterized by their very high demand for computing, storage and network bandwidth requirements. Grid applications require secure, controlled, reliable, and guaranteed access to different types of resources, such as network bandwidth, computing power, and storage capabilities, available from multiple service providers. Moreover, they demand multiple, simultaneous end-to-end quality of service (QoS) properties, such as delay guarantees, jitter guarantees, security, scalability, reliability and availability guarantees, and bandwidth and throughput guarantees, for their effective operation. Existing grid infrastructure middleware, such as Globus, ICENI, and Legion,