Processor group membership protocols: Specification, design and implementation

This paper presents the specification, design and implementation of a set of protocols to solve the processor group membership problem in distributed systems. These group membership protocols were developed as part of a toolkit for building distributed/parallel applications on a cluster of workstations. The group membership service forms the lowest layer in the toolkit, and it is the glue which unifies all other layers. The membership service supports three distinct protocols: weak, strong, and hybrid. These protocols differ significantly in the level of consistency and the number of messages exchanged in reaching agreement. The paper also describes the modular implementation of these protocols and the optimization techniques used to enhance their performance.