Service resilience, defined as the continued availability of a service despite failures and other negative changes in its environment, is vital in many systems. It is typically achieved by state machine replication using group communication middleware for coordination of service replicas. In this paper we focus on systems that represent critical data as Web resources identified by Uniform Resource Identifiers (URIs). The best examples of such systems are RESTful web services. We present RESTGroups: a group communication front-end for RESTful web services. Our system is based on Spread – a popular group communication toolkit. Contrary to Spread and other such toolkits, we represent group communication services as resources on the Web, addressed by URIs. In the paper, we describe the system architecture and the API.
Tadeusz Kobus, Pawel T. Wojciechowski