A Packager for Multicast Software in Distributed Systems

PTM is a packagmg tool for preparing ordinary software to execute in multicast-based environments. Using PTM, both individual programs and systems of programs can be tailored to use multicast communication, without manual intervention from the programmer , who is in turn free to reason about the distributed system's initial configuration as if ordinary RPC or message passing semantics are to be used. But with PTM, programmers also retain the flexibility afforded at run time by the multicast paradigm, wher e the set of tools that consume a given type of event can transparently evolve. After describing Polycast, our implementation of a multicast execution environment in terms of software bus organization, we present the packaging technology that automates p reparation of software for the environment. Software prototyping is one of the key beneficiaries of multicast communication, which led us to explore means for simplifying the programming tasks involved; and therefore we illustrate how Polyvast is serving our prototyping research by presenting an example prototyping tool called PTM, in which our multicast enables users to dynamically explore network design and configuration alternatives. (Also cross-referenced as UMIACS-TR-92-114