A scalable decentralized group membership service for an asynchronous environment

Abstract

This thesis presents a globally scalable, decentralized group membership service to manage client process groups operating in a distributed, asynchronous environment. This group membership service is totally scalable, handling process groups spanning a single LAN to groups spanning the entire global Internet equally well. It provides for nested and overlapping groups, as well as multiple groups residing on a single LAN. It also provides various Quality of Service selections which permit individual groups to be configured for an optimal balance between high quality with strong consistency semantics for group membership, and weaker consistency semantics with reduced complexity and latency. This thesis describes the complete design of the protocol used to implement the group membership service. It presents the design requirements and goals, and underlying assumptions about the network. The various Quality of Service selections provided by the group membership service are described in detail, as well as the interface between the process groups, the membership service, and the underlying network. The use of a hierarchical architecture to obtain the desired scalability, flexibility, and robustness is explained. A proof of correctness for the protocol is presented, and a partial implementation of the group membership service is described