The MultiSpace: An Evolutionary Platform for Infrastructural Services

This paper presents the architecture for a Base, a clustered environment for building and executing highly available, scalable, but exible and adaptable infrastructure services. Our architecture has three organizing principles: addressing all of the diÆcult service faulttolerance, availability, and consistency problems in a carefully controlled environment, building that environment out of a collection of execution environments that are receptive to mobile code, and using dynamically generated code to introduce run-time-generated levels of indirection separating clients from services. We present a prototype Java implementation of a Base called the MultiSpace, and talk about two applications written on this prototype: the Ninja Jukebox (a cluster based music warehouse), and Keiretsu (an instant messaging service that supports heterogeneous clients). We show that the MultiSpace implementation successfully reduces the complexity of implementing services, and that the platform is conducive to rapid service evolution.