relation: http://eprints.imtlucca.it/122/ title: CC-Pi: A Constraint-Based Language for Specifying Service Level Agreements creator: Buscemi, Maria Grazia creator: Montanari, Ugo subject: QA75 Electronic computers. Computer science description: Service Level Agreements are a key issue in Service Oriented Computing. SLA contracts specify client requirements and service guarantees, with emphasis on Quality of Service (cost, performance, availability, etc.). In this work we propose a simple model of contracts for QoS and SLAs that also allows to study mechanisms for resource allocation and for joining different SLA requirements. Our language combines two basic programming paradigms: name-passing calculi and concurrent constraint programming (cc programming). Specifically, we extend cc programming by adding synchronous communication and by providing a treatment of names in terms of restriction and structural axioms closer to nominal calculi than to variables with existential quantification. In the resulting framework, SLA requirements are constraints that can be generated either by a single party or by the synchronisation of two agents. Moreover, restricting the scope of names allows for local stores of constraints, which may become global as a consequence of synchronisations. Our approach relies on a system of named constraints that equip classical constraints with a suitable algebraic structure providing a richer mechanism of constraint combination. We give reduction-preserving translations of both cc programming and the calculus of explicit fusions. publisher: Springer contributor: De Nicola, Rocco date: 2007 type: Book Section type: PeerReviewed identifier: Buscemi, Maria Grazia and Montanari, Ugo CC-Pi: A Constraint-Based Language for Specifying Service Level Agreements. In: Proceedings of the 16th European Symposium on Programming (ESOP’07). Lecture Notes in Computer Science, 4421 . Springer, pp. 18-32. ISBN 978-3-540-71314-2 (2007) relation: http://dx.doi.org/10.1007/978-3-540-71316-6_3 relation: 10.1007/978-3-540-71316-6_3