A Theory of Adaptable Contract-Based Service Composition

Abstract

Service Oriented Architectures draw heavily on techniques for reusing and assembling off-the-shelf software components. While powerful, this programming practice is not without a cost: the software architect must ensure that the off-the-shelf components interact safely and in ways that conform with the specification. We develop a new theory for adaptable service compositions. The theory provides an effective framework for analyzing the conformance of contract-based service compositions, and for enforcing their compliance, in a uniform, and formally elegant setting.

A theory of contracts for web services

“…This is proved by Bernardi et al [2008] who extend our work (more precisely the version in ) for dealing with choreographies of Web services. Apart from a few technical differences-Bernardi et al disallow different summands of an external choice guarded by the same action and uses a fair variant of compliance- [Bernardi et al 2008] shows how filters provide a new interesting solution to the problem of Web service composition [Traverso and Pistore 2004;Berardi et al 2003;Hull et al 2003;Pistore et al 2005; De Giacomo and Sardiña [Berardi et al 2003;De Giacomo and Sardiña 2007].…”

“…Apart from a few technical differences-Bernardi et al disallow different summands of an external choice guarded by the same action and uses a fair variant of compliance- [Bernardi et al 2008] shows how filters provide a new interesting solution to the problem of Web service composition [Traverso and Pistore 2004;Berardi et al 2003;Hull et al 2003;Pistore et al 2005; De Giacomo and Sardiña [Berardi et al 2003;De Giacomo and Sardiña 2007]. In [Bernardi et al 2008] both contracts and filters are associated with locations and can be composed for describing and constraining the participants interacting in a choreography. The notion of compliance is extended to compositions of located contracts and an algorithm is defined that infers the greatest relevant composite filter (cf.…”

Compliance Preorders for Web Services

“…Besides investigating the relationships between the existing definitions of compliance, we have also shown how to obtain compliance preorders for multiparty service compositions, by recasting and generalizing the theory of behavioral coercions from [8,9] to this setting. Our present endeavor continues on the line of work we initiated in [2]. There, we used filters to provide a new solution to the problem of web service adaptation within service compositions [18,1,10].…”

“…We conclude that σ C s , against the hypothesis. Thus the only possible case is (2): there exists at least one ρ = ρ n such that ρ n C n =⇒ ρ C and moreover for every ρ such that ρ n C n =⇒ ρ C it holds ρ = ρ i for some i < n. Thus for every ρ such that ρ n C n =⇒ ρ C it holds: ρ Since (σ C s ) there exists a computation σ n C n =⇒ σ * C * such that (σ * C * ) . In particular σ n w * =⇒ σ * .…”

A theory of contracts for web services

“…§3.4.1 in this work) that makes a composition of located contracts satisfy compliance (which corresponds to our Corollary 3.24). Additionally Bernardi et al [2008] propose a new usage of filters, which can be seen as a specification of the roles occupied by the participants of a choreography.…”