1,721,241 research outputs found
On the potential advantages of exploiting behavioural information for contract-based service discovery and composition
No full textAbstractThe importance of service contracts providing a suitably synthetic description of software services is widely accepted. While different types of information – ranging from extra-functional properties to ontological annotations to behavioural descriptions – have been proposed to be included in service contracts, no widely accepted de facto standard has yet emerged for describing service contracts, except for signature information. The lack of a de facto standard is inhibiting large scale deployment of techniques and tools supporting enhanced discovery and composition of services.In this paper we discuss the potentially huge advantages of exploiting behavioural information for service discovery and composition, and relate them to the cost of generating such information and to the needed trade-off between expressiveness and cost and value of analysing such information. On such ground, we also discuss the potential suitability of some well-known modelling approaches to become the de facto standard to represent service behaviour in contracts, also in view of contextual factors (such as required know-how and current employment)
Ontology- and behaviour-aware discovery of Web service compositions
No full textOntology- and behaviour-aware discovery of Web service composition
Anomaly Detection and Failure Root Cause Analysis in (Micro) Service-Based Cloud Applications: A Survey
Get PDFThe proliferation of services and service interactions within microservices and cloud-native applications, makes it harder to detect failures and to identify their possible root causes, which is, on the other hand crucial to promptly recover and fix applications. Various techniques have been proposed to promptly detect failures based on their symptoms, viz., observing anomalous behaviour in one or more application services, as well as to analyse logs or monitored performance of such services to determine the possible root causes for observed anomalies. The objective of this survey is to provide a structured overview and qualitative analysis of currently available techniques for anomaly detection and root cause analysis in modern multi-service applications. Some open challenges and research directions stemming out from the analysis are also discussed
Fully Abstract Compositional Semantics for an Algebra of Logic Programs
No full textAbstractA simple extension of logic programming consists of introducing a set of basic program composition operations, which form an algebra of logic programs with interesting properties for reasoning about programs and program compositions. From a programming perspective, the operations enhance the expressive power of the logic programing paradigm by supporting a wealth of programming techniques, ranging from software engineering to artificial intelligence applications.This paper focuses on the semantics of program composition operations. It is shown that the immediate consequence operator T(P) properly characterises the intended meaning of a program P when considering compositions of programs. More precisely, it is shown that the T(P) semantics is both compositional and fully abstract w.r.t. the set of composition operations of the algebra. This implies that the T(P) semantics induces the coarsest equivalence relation on programs (subsumption-equivalence) and that any other semantics of programs must induce the same equivalence relation to be both compositional and fully abstract w.r.t. the whole set of operations of the algebra. The T(P) semantics is then related to other well known semantics for logic programs which induce coarser equivalence relations. In particular, three equivalence relations, originally studied by Maher (1988), are considered: Weak subsumption-equivalence, logical equivalence and least Herbrand model equivalence. It is shown that the chain of equivalence relations composed by weak subsumption-equivalence, logical equivalence and least Herbrand model equivalence coincides with the chain of fully abstract compositional equivalence relations for proper subsets of the operations of the algebra, obtained by dropping one operation at a time from the set of compositions
Behaviour-aware discovery of Web service compositions
No full textA major challenge for Service-oriented Computing is how to discover and compose (Web) services to build complex applications. We present a matchmaking system that exploits both semantics and behavioural information to discover service compositions capable of satisfying a client request
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