A Configurable Membership Service

A membership service is used to maintain information about which sites are functioning in a distributed system at any given time. Many such services have been defined, with each implementing a unique combination of properties that simplify the construction of higher levels of the system. Despite this wealth of possibilities, however, any given service only realizes one set of properties, which makes it difficult to tailor the service provided to the specific needs of the application. Here, a configurable membership service that addresses this problem is described. This service is based on decomposing membership into its constituent abstract properties, and then implementing these properties as separate software modules called micro-protocols that can be configured together to produce a customized membership service. A prototype C++ implementation of the membership service for a simulated distributed environment is also described.