Biochemical Tuple Spaces for Self-organising Coordination Mirko Viroli and Matteo Casadei Alma Mater Studiorum – Universit`a di Bologna via Venazia 52, 47023 Cesena, FC, Italy {mirko.viroli,m.casadei}@unibo.it Abstract. Inspired by recent works in computational systems biology and existing literature proposing nature-inspired approaches for the co- ordination of today complex distributed systems, this paper proposes a mechanism to leverage exact computational modelling of chemical reac- tions for achieving self-organisation in system coordination. We conceive the notion of biochemical tuple spaces. In this model: a tuple resembles a chemical substance, a notion of activity/pertinency value for tuples is used to model chemical concentration, coordination rules are structured as chemical reactions evolving tuple concentration over time, a tuple space resembles a single-compartment solution, and finally a network of tuple spaces resembles a tissue-like biological system. The proposed model is formalised as a process algebra with stochastic semantics, and several examples are described up to an ecology-inspired scenario of system coordination, which emphasises the self-organisation features of the proposed model. 1 Introduction The characteristics of the ICT landscape – yet notably changed by the advent of ubiquitous wireless connectivity – will further re-shape due to the increasing deployment of computing technologies like pervasive services and social networks: new devices with increasing interaction capabilities will be exploited to create services that inject and retrieve data from any location of the very dynamic and dense network that will pervade our everyday environments. Addressing this scenario calls for finding infrastructures promoting a concept of eternality, namely, changes in topology, device technology, and continuous creation of new services, have to be dynamically tolerated as much as possible, and incorporated with no significant re-engineering costs at the middleware level [30]. As far as coordination is concerned, this means that coordination models will increasingly be required to tackle self-adaptation, self-management, self-optimisation – in one word, full self-organisation – as inherent system properties rather than peculiar aspects of individual coordinated components. The concept of self-organising coordination then enters the picture, which is based on the idea of structuring local coordination rules – which are possi- bly stochastic and timed – so as to make interesting global properties appear J. Field and V.T. Vasconcelos (Eds.): COORDINATION 2009, LNCS 5521, pp. 143–162, 2009. c  Springer-Verlag Berlin Heidelberg 2009