Communication and Data Sharing for Dynamic Distributed Systems

Abstract

This research direction aims to develop and analyze algorithms to solve problems of communication and data sharing in highly dynamic distributed environments. The term dynamic here encompasses many types of changes, including changing network topology, processor mobility, changing sets of participating client processes, a wide range of types of processor and network failures, and timing variations. Constructing distributed applications for such environments is a difficult programming problem. In practice, considerable effort is required to make applications resilient to changes in client requirements and to evolution of the underlying computing medium. We focus our work on distributed services that provide useful guarantees and that make the construction of sophisticated distributed applications easier. The properties we study include ordering and reliability guarantees for communication and coherence guarantees for data sharing. To describe inherent limitations on what problems can be solved, and at what cost, the algorithmic results will be accompanied by lower bound and impossibility results. One example of our approach is the new dynamic atomic shared-memory service for message-passing systems. We formally specified the service and developed algorithms implementing the service. A system implementation is under development. The service is reconfigurable in the sense that the set of owners of data can be changed dynamically and concurrently with the ongoing read and write operations.

This work is supported by the NSF Grants 0121277, 9988304 and 9984774.