Towards an aspect weaving BPEL engine

This position paper proposes the use of dynamic aspects and the visitor design pattern to obtain a highly configurable and extensible BPEL engine. Using these two techniques, the core of this infrastructural software can be customised to meet new requirements and add features such as debugging, execution monitoring, or changing to another Web Service selection policy. Additionally, it can easily be extended to cope with customer-specific BPEL extensions. We propose the use of dynamic aspects not only on the engine itself but also on the workflow in order to tackle the problems of Web Service hot deployment and hot fixes to long running processes. In this way, composing aWeb Service "on-the-fly" means weaving its choreography interface into the workflow

Exploiting rules and processes for increasing flexibility in service composition

Recent trends in the use of service oriented architecture for designing, developing, managing, and using distributed applications have resulted in an increasing number of independently developed and physically distributed services. These services can be discovered, selected and composed to develop new applications and to meet emerging user requirements. Service composition is generally defined on the basis of business processes in which the underlying composition logic is guided by specifying control and data flows through Web service interfaces. User demands as well as the services themselves may change over time, which leads to replacing or adjusting the composition logic of previously defined processes. Coping with change is still one of the fundamental problems in current process based composition approaches. In this paper, we exploit declarative and imperative design styles to achieve better flexibility in service composition

A Taxonomy of Variability in Web Service Flows

The combination of Software Product Lines (SPL) and Service-Oriented Architectures (SOA) development practices is expected to become a new development paradigm maximizing reuse and business integration. However, multiples issues must be still addressed in order to clarify the connections between both fields. One of the key questions to answer is how SPL practices can be used to support serviceoriented applications. in this context, identifying and managing the points of variability in composite Web services emerges as an inevitable step for making possible such integration. in this position paper we give a first step toward such direction by introducing a comprehensible overview of the main variability points in Web service flows.Ministerio de Educación y Ciencia TIN2006-0047

A Framework for Interoperability Across Heterogeneous Service Description Models

Automated Web service processing, composition and execution is a research area that has yielded different service description models that can be implemented using a wide array of standards and technologies. Due to the diversity of their underlying service description models and the specific operational standards and platforms they are using, it has been difficult to fairly compare various research solutions pertaining to Web service processing, composition and execution. All solutions require a Web service description repository, for example, to automatically compose and execute composite services. Different research endeavors have provided original and diverse solutions to these Web service processing problems, many of them being extensions to existing solutions using standard service description models. We propose a highly modular Web service description framework that can allow the user to import, export, search, modify, and enable the composition and execution of services described using different service description models and/or standards. Our service description framework uses a simple and flexible interface to test and compare Web service processing, composition and execution models and algorithms. We evaluate our framework by creating specific instances of our framework to achieve concrete motivation scenarios, which we do successfully, achieving all of our goals

Leveraging service-oriented business applications to a rigorous rule-centric dynamic behavioural architecture.

Today’s market competitiveness and globalisation are putting pressure on organisations to join their efforts, to focus more on cooperation and interaction and to add value to their businesses. That is, most information systems supporting these cross-organisations are characterised as service-oriented business applications, where all the emphasis is put on inter-service interactions rather than intra-service computations. Unfortunately for the development of such inter-organisational service-oriented business systems, current service technology proposes only ad-hoc, manual and static standard web-service languages such as WSDL, BPEL and WS-CDL [3, 7]. The main objective of the work reported in this thesis is thus to leverage the development of service-oriented business applications towards more reliability and dynamic adaptability, placing emphasis on the use of business rules to govern activities, while composing services. The best available software-engineering techniques for adaptability, mainly aspect-oriented mechanisms, are also to be integrated with advanced formal techniques. More specifically, the proposed approach consists of the following incremental steps. First, it models any business activity behaviour governing any service-oriented business process as Event-Condition-Action (ECA) rules. Then such informal rules are made more interaction-centric, using adapted architectural connectors. Third, still at the conceptual-level, with the aim of adapting such ECA-driven connectors, this approach borrows aspect-oriented ideas and mechanisms, and proposes to intercept events, select the properties required for interacting entities, explicitly and separately execute such ECA-driven behavioural interactions and finally dynamically weave the results into the entities involved. To ensure compliance and to preserve the implementation of this architectural conceptualisation, the work adopts the Maude language as an executable operational formalisation. For that purpose, Maude is first endowed with the notions of components and interfaces. Further, the concept of ECA-driven behavioural interactions are specified and implemented as aspects. Finally, capitalising on Maude reflection, the thesis demonstrates how to weave such interaction executions into associated services

Achieving autonomic Web service compositions with models at runtime

[EN] Several exceptional situations may arise in the complex, heterogeneous, and changing contexts where Web service operations run. For instance, a Web service operation may have greatly increased its execution time or may have become unavailable. The contribution of this article is to provide a tool-supported framework to guide autonomic adjustments of context-aware service compositions using models at runtime. During execution, when problematic events arise in the context, models are used by an autonomic architecture to guide changes of the service composition. Under the closed-world assumption, the possible context events are fully known at design time. Nevertheless, it is difficult to foresee all the possible situations arising in uncertain contexts where service compositions run. Therefore, the proposed framework also covers the dynamic evolution of service compositions to deal with unexpected events in the open world. An evaluation demonstrates that our framework is efficient during dynamic adjustments.Alférez-Salinas, GH.; Pelechano Ferragud, V. (2017). Achieving autonomic Web service compositions with models at runtime. Computers & Electrical Engineering. 63:332-352. doi:10.1016/j.compeleceng.2017.08.004S3323526