On the Power of Attribute-Based Communication

Abstract

Abstract. In open systems, i.e. systems operating in an environment that they cannot control and with components that may join or leave, behaviors can arise as side effects of intensive components interaction. Finding ways to understand and design these systems and, most of all, to model the interactions of their components, is a difficult but important endeavor. To tackle these issues, we present AbC , a calculus for attributebased communication. An AbC system consists of a set of parallel agents each of which is equipped with a set of attributes. Communication takes place in an implicit multicast fashion, and interactions among agents are dynamically established by taking into account "connections" as determined by predicates over the attributes of agents. First, the syntax and the semantics of the calculus are presented, then expressiveness and effectiveness of AbC are demonstrated both in terms of modeling scenarios featuring collaboration, reconfiguration, and adaptation and of the possibility of encoding channel-based interactions and other interaction patterns. Behavioral equivalences for AbC are introduced for establishing formal relationships between different descriptions of the same system.

A Formal Approach to the Engineering of Domain-Specific Distributed Systems

“…AbC (Attribute-based Communication calculus, [103,9,104]) is a process calculus specifically designed to deal with CAS. It has been heavily inspired by Scel, but has been designed to reduce complexity and keep the set of linguistic primitives to a minimum.…”

“…Instead, to deal with autonomic computing the Scel language [8] was introduced that had explicit notions of agents knowledge and primitives and policies for its manipulations together with an original approach to ad hoc ensembles formation (Section 4). Finally, to model and prove emergent properties of collective adaptive systems a distilled version of Scel named AbC [9] was introduced that had specific operators for selecting communication partners using predicates on the run time value of relevant attributes of the agents forming the system (Section 5).…”

Rigorous Graphical Modelling of Movement in Collective Adaptive Systems

“…Thus communication based on addresses represented by entity identity or location will fail when entities enter and leave the system and change their location. We choose to use a process algebra-style language in which entities are represented as components and communication is attribute-based, meaning that communication partners are selected according to their characteristics rather than their identity or location [2]. The language concerned is CARMA (Collective Adaptive Resource-sharing Markovian Agents), a high-level language designed specifically for modelling CAS [1].…”

Modelling and Analysis of Collective Adaptive Systems with CARMA and its Tools

“…The stochastic variant of SCEL, called StocS [22], was a first step towards the investigation of the impact of different stochastic semantics for autonomic processes, that relies on stochastic output semantics, probabilistic input semantics and on a probabilistic notion of knowledge. Moreover, SCEL has inspired the development of the core calculus AbC [2,1] that focuses on a minimal set of primitives that defines attributebased communication, and investigates their impact. Communication among components takes place in a broadcast fashion, with the characteristic that only components satisfying predicates over specific attributes receive the sent messages, provided that they are willing to do so.…”