Intra- and inter-object coordination with MESSENGERS

Abstract

MESSENGERS is a paradigm for the programming of distributed systems. It is based on the principles of autonomous messages, called Messengers, which carry their own behavior in the form of a program. This enables them to navigate freely in the underlying computational network, communicate with one another, and invoke pre-compiled node-resident functions. Coordination is facilitated at two distinct levels of abstraction: first, Messengers coordinate the invocation and the exchange of data among the various functions distributed throughout the network in both time and space (intra-object coordination); second, Messengers, each representing a high-level entity, can coordinate their behaviors among themselves (inter-object coordination). These principles, where an application is composed of autonomous, mobile entities whose behaviors may change dynamically and which can coordinate their actions among themselves, offer great flexibility in interacting with and manipulating the application at run time, as well as improved performance. This is illustrated using two concrete examples—a Toxicology simulation from medicine and a study of collective fish behavior from biology.