An Integrated Group Communication Infrastructure for Hybrid Real-time Distributed Systems

Raimundo José de Araújo Macêdo

Group Communication is a powerful abstraction that is being widely used to manage consistency problems in a variety distributed system models, ranging from synchronous, to time-free asynchronous model. Though similar in principles, distinct implementation mechanisms have been employed in the design of group communication for distinct system models. However, the hybrid nature of many modern (real-time) distributed systems, with distinct QoS guarantees, has put forward the need for integrated models, where both hard and soft real-time application services must be provided within the very same system. Moreover, in such scenarios, adaptation with degraded service is a common requirement. This paper tackles this new challenge by introducing a mechanism called the Timed Causal Blocks, which is an extension of the so-called Causal Blocks model used for asynchronous systems. Because they combine physical and logical time in the same infrastructure, Timed Causal Blocks represents an integrated framework capable of handling group communication for both synchronous hard real-time and asynchronous soft real-time distributed systems. This paper describes the information structure of Timed Causal Blocks and sketches the related algorithms intended to total order message delivery and dynamic membership reconfiguration. Moreover, it is shown that the ordering and reliability information provided by the Causal Blocks can be used to anticipate message delivery, and timely delivery can be achieved without relying on clock synchronization.

Caso o link acima esteja inválido, faça uma busca pelo texto completo na Web: Buscar na Web

Biblioteca Digital Brasileira de Computação - Contato:
     Mantida por: