Extended virtual synchrony

We formulate a model of extended virtual synchrony that defines a group communication transport service for multicast and broadcast communication in a distributed system. The model extends the virtual synchrony model of the Isis system to support continued operation in all components of a partitioned network. The significance of extended virtual synchrony is that, during network partitioning and remerging and during process failure and recovery, it maintains a consistent relationship between the delivery of messages and the delivery of configuration changes across all processes in the system and provides well-defined self-delivery and failure atomicity properties. We describe an algorithm that implements extended virtual synchrony and construct a filter that reduces extended virtual synchrony to virtual synchrony.<>