SDI Seminar

Speaker: Brian Noble

A Programming Interface for Application-Aware Adaptation in Mobile Computing

Date: April 7, 1995

Abstract: Mobile clients face wide variations in network conditions and local resource availability when accessing remote data. Coping with this uncertainty requires the ability to retrieve and present data at varying degrees of fidelity. In this paper we present applicaton-aware adaptation as a solution to this problem. The essence of our solution is a collaborative partnership between applications and the operating system. We describe the Odyssey API for application-aware adaptation and demonstrate its use in accessing two types of data: video and maps.

Joint work with Morgan Price and M. Satyanarayanan

Application-Aware Adaptation for Mobile Computing

Date: September 8, 1994

Abstract: This talk identifies application-aware adaptation as an essential capability of mobile clients, and provides an overview of Odyssey, an architecture that supports this capability. Functionality that has hitherto been implemented monolithically must now be split between the operating system and individual applications. The role of the operating system is to sense external events, and to monitor and allocate scarce resources. In contrast, the role of individual applications is to adapt to changing conditions by using the information and resources provided by the operating system.

Joint work with: M. Satyanarayanan, P. Kumar, M. Price

An Empirical Study of a Highly Available File System

Date: May 12, 1994

Abstract: In this paper we present results from a six-month empirical study of the high availability aspects of the Coda File System. We report on the service failures experienced by Coda clients, and show that such failures are masked successfully. We also explore the effectiveness and resource costs of key aspects of server replication and disconnected operation}, the two high availability mechanisms of Coda. Wherever possible, we compare our measurements to simulation- based predictions from earlier papers and to anecdotal evidence from users. Finally, we explore how users take advantage of the support provided by Coda for mobile computing.