Governing distributed systems: from protocols to laws

This paper is concerned with the problem of the implementation of protocols, particularly in the case of heterogeneous, evolving and open distributed systems. If one is to have any confidence that a given protocol is obeyed by all objects of a distributed system, this protocol must somehow be enforced. In order to facilitate enforcement of protocols, the author introduces a new architecture for distributed systems under which all interactions between objects are governed by an explicit and strictly enforced set of rules, called the law of the system. This law is global, in the sense that all the objects of the system are made to obey it, but the maintenance of the law and its enforcement are performed locally, at each object. The law, then, is the enforced specification of protocols.<>