Title: A process calculus for Specifying Service Level Agreements and Resource Allocation
Speaker:Marzia Buscemi
IMT Lucca Institute for Advanced Studies & University of Pisa, Italy
Time: 3pm, Monday June 4
Venue: Lecture room, Lab for Computer Science, Level 3 Building #5, Institute of Software, CAS


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 talk, 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