This project considers specifically two QoS dimensions - availability and network resource management and investigates methods by which objects can specify and obtain the quality of service they desire. Today's applications cannot specify availability requirements and generally cannot adapt to changes in resource availability. Similarly, current networks and their applications are designed to function independently, without knowledge of the other's internal mechanisms, priorities, or constraints. While this black box approach reduces the complexity of developing networks and applications, it seriously hinders the ability for mutual adaptation. Networks cannot adapt to serve the needs of specific applications.
Applications can neither control nor adapt to network performance or resource availability.
The objective of this project is to make orders of magnitude improvement in providing ways for applications to manage the quality of service they receive from a system distributed over a wide area network. We achieve this objective by providing advanced resource management strategies, facilitating adaptation of the applications when their needs cannot be met, and enhancing infrastructure mechanisms to support dynamic behavior. The availability component of the AQuA architecture supports multiple types of replication and is capable of tolerating crash and value faults. The focus of AQuA is to develop sophisticated QoS mechanisms in the areas of dependability and managed network resources. In addition, AQuA will make initial investigations into the implications of combinations and tradeoffs of these two QoS dimensions.