Towards autonomic service-oriented applications

Lecture Notes in Computer Science, 2015

In the near future we will be surrounded by a virtually infinite number of software applications that provide services in the digital space. This situation radically changes the way software will be produced and used: (i) software is increasingly produced according to specific goals and by integrating existing software; (ii) the focus of software production will be shifted towards reuse of third-parties software, typically blackbox, that is often provided without a machine readable documentation. The evidence underlying this scenario is that the price to pay for this software availability is a lack of knowledge on the software itself, notably on its interaction behaviour. A producer will operate with software artefacts that are not completely known in terms of their functional and non-functional characteristics. The general problem is therefore directed to the ability of interacting with the artefacts to the extent the goal is reached. This is not a trivial problem given the virtually infinite interaction protocols that can be defined at application level. Different software artefacts with heterogeneous interaction protocols may need to interoperate in order to reach the goal. In this paper we focus on techniques and tools for integration code synthesis, which are able to deal with partial knowledge and automatically produce correct-by-construction serviceoriented systems with respect to functional goals. The research approach we propose builds around two phases: elicit and integrate. The first concerns observation theories and techniques to elicit functional behavioural models of the interaction protocol of black-box services. The second deals with compositional theories and techniques to automatically synthesize appropriate integration means to compose the services together in order to realize a service choreography that satisfies the goal.

International Journal of Pervasive Computing and Communications, 2019

Purpose This paper aims to propose an approach for the self-adaptation of the Web composition called SAMIWA. The SAMIWA framework helps users during the search, invocation and composition of the appropriate Web service. Design/methodology/approach The authors’ approach allows expressing requirements by taking into account potential users’ context in addition to the functional one. Findings In this paper, the authors introduce a new context-aware approach that provides a dynamic adaptation of service compositions. Originality/value The author has implemented a Web application that enables selection and composition of the most appropriate composite service.

Adaptation is of utmost importance in systems developed by assembling reusable software services accessed through their public interfaces. This process aims at solving, as automatically as possible, mismatch cases which may be given at the different interoperability levels among interfaces by synthesizing a mediating adaptor. In this paper, we present a toolbox that fully supports the adaptation process, including: (i) different methods to construct adaptation contracts involving several services; (ii) simulation and verification techniques which help to identify and correct erroneous behaviours or deadlocking executions; and (iii) techniques for the generation of centralized or distributed adaptor protocols based on the aforementioned contracts. Our toolbox relates our models with implementation platforms, starting with the automatic extraction of behavioural models from existing interface descriptions, until the final adaptor implementation is generated for the target platform.

Lecture Notes in Computer Science, 2009

Increasingly complex information systems operating in dynamic environments ask for management policies able to deal intelligently and autonomously with problems and tasks. An attempt to deal with these aspects can be found in the Service-Oriented Architecture (SOA) paradigm that foresees the creation of business applications from independently developed services, where services and applications build up complex dependencies. Therefore the dependability of SOA systems strongly depends on their ability to self-manage and adapt themselves to cope with changes in the operating conditions and to meet the required dependability with a minimum of resources. In this paper we propose a model-based approach to the realization of self-adaptable SOA systems, aimed at the fulfillment of dependability requirements. Specifically, we provide a methodology driving the system adaptation and we discuss the architectural issues related to its implementation. To bring this approach to fruition, we developed a prototype tool and we show the results that can be achieved with a simple example.

Socially Enhanced Services Computing, 2011

Mixed service-oriented systems composed of human actors and software services build up complex interaction networks. Without any coordination, such system may exhibit undesirable properties due to unexpected behavior. Also, communications and interactions in such networks are not preplanned by top-down composition models. Consequently, the management of service-oriented applications is difficult due to changing interaction and behavior patterns that possibly contradict and result in faults from varying conditions and misbehavior in the network. In this paper we present a self-adaptation approach that regulates local interactions to maintain desired system functionality. To prevent degraded or stalled systems, adaptations operate by link modification or substitution of actors based on similarity and trust metrics. Unlike a security perspective on trust, we focus on the notion of socially inspired trust. We design an architecture based on two separate independent frameworks. One providing a real Web service testbed extensible for dynamic adaptation actions. The other is our self-adaptation framework including all modules required by systems with self-* properties. In our experiments we study a trust and similarity based adaptation approach by simulating dynamic interactions in the real Web services testbed.

Service Oriented Computing and Applications, 2013

Service-oriented computing is a promising computing paradigm which facilitates the composition of loosely coupled and adaptable servicebased applications. Unfortunately, this new paradigm does not lend itself easily to traditional software engineering methods and principles due to the decentralized nature of software services. The goal of this paper is to identify a set of engineering activities that can be used to develop adaptable servicebased applications. Rather than focusing on the entire service-based application development lifecycle, this paper will focus on adaptation specific processes and activities and map them to an existing high-level SBA development life-cycle. Existing software engineering literature as well as research results from service engineering research are reviewed for relevant activities. The result is an adaptation framework that can guide software engineers in developing adaptable service-based applications.

2011

Abstract: The study of adaptivity, ie, the capability to react to changes in the environment, is becoming ever more important in many fields of study, and in the development of software in particular. This paper presents a systematic review in which both the extension and complexity of this notion are examined. After studying the influence from external fields, this review checks the hypothesis of using the scope of service-oriented architecture as a comparable model for the whole field.

Proceedings of the 3rd workshop …, 2008

IEEE Transactions on …, 2009