Group communication in partitionable systems: Specification and algorithms

give a formal specification and an implementation for a partitionable group communication service in asynchronous distributed systems. Our specificati on is motivated by the requirements for building "partition-aware" applicat ions that can continue operating without blocking in multiple concurrent pa rtitions and reconfigure themselves dynamically when partitions merge. The specified service guarantees liveness and excludes trivial solutions, it co nstitutes a useful basis for building realistic partition-aware application s, and it is implementable in practical asynchronous distributed systems wh ere certain stability conditions hold.