Service-oriented Enterprise Systems Research Articles

A View-based Approach to Quality of Service Modelling in Service-oriented Enterprise Systems

Service-oriented enterprise architecture and emerging advanced technologies bring up new problems for enterprise systems engineering or, more exactly, for service-oriented enterprise systems (SoESs) engineering. One of the most important issues is the modelling of quality of services (QoS). The QoS is a complex and multi-sided concept. In various contexts and for different aims it may be defined quite differently. In the context of SoES, QoS has also some specifics that in several aspects differ from the systems implementing service-oriented architecture (SOA) in other contexts, for example, in business-to-consumer or utility-service ones. The paper suggests that it is possible to identify several understandings of QoS reflecting the viewpoints of different SoES stakeholders in a similar way as it is carried out for software products. It also proposes a conceptual view-based framework for QoS modelling in web-based SoES and for balancing different viewpoints.

Architecture-level software performance abstractions for online performance prediction

Modern service-oriented enterprise systems have increasingly complex and dynamic loosely-coupled architectures that often exhibit poor performance and resource efficiency and have high operating costs. This is due to the inability to predict at run-time the effect of workload changes on performance-relevant application-level dependencies and adapt the system configuration accordingly. Architecture-level performance models provide a powerful tool for performance prediction, however, current approaches to modeling the context of software components are not suitable for use at run-time. In this paper, we analyze typical online performance prediction scenarios and propose a performance meta-model for (i) expressing and resolving parameter and context dependencies, (ii) modeling service abstractions at different levels of granularity and (iii) modeling the deployment of software components in complex resource landscapes. The presented meta-model is a subset of the Descartes Meta-Model (DMM) for online performance prediction, specifically designed for use in online scenarios. We motivate and validate our approach in the context of realistic and representative online performance prediction scenarios based on the SPECjEnterprise2010 standard benchmark.

A Model of View-Based Enterprise Business Service Quality Evaluation Framework

The symbiosis between an enterprise architecture and service-oriented architecture results in so-called service-oriented enterprise architecture and brings up new problems for service-oriented enterprise systems engineering. One of the most important is a business service quality definition, specification and evaluation. The paper proposes a formal model of enterprise business service quality evaluation framework to encompass and balance all the viewpoints and perspectives on an enterprise business service quality.

A lightweight and extensible Complex Event Processing system for sense and respond applications

Complex Event Processing (CEP) is considered as a promising technology for enabling the evolution of service-oriented enterprise systems towards operational aware systems. CEP effectively supports the implementation of “sense and respond” behaviours, as it enables to extract meaningful events from raw data streams originated by sensing infrastructures, for enterprise processes and applications consumption. This paper proposes a novel CEP engine conceived with ease of use, extensibility, portability, and scalability requirements in mind. More specifically, we propose a Lightweight Stage-based Event Processor (LiSEP) based on a layered architectural design. Thanks to the adoption of Staged Event-Driven Architecture principles, core event processing logic is decoupled from low-level thread management issues. This results in an easy-to-understand and extensible implementation while testing results show performance scalability. We report on the carrying out of a case study on dangerous goods monitoring in maritime transport. The objective of the case study is to develop a Proof of Concept application leveraging on LiSEP capabilities in sensor and RFID events processing for monitoring and alerting purposes.

Template-Based Adaptation of Semantic Web Services with Model-Driven Engineering

Service-oriented enterprise systems, which tend to be heterogeneous, loosely coupled, long-lived, and continuously running, have to cope with frequent changes to their requirements and the environment. In order to address such changes, applications need to be inherently flexible and adaptive, supported by appropriate infrastructures. In this paper, we propose a model-driven approach for the dynamic adaptation of Web services based on ontology-aware service templates. Model-driven engineering raises the level of abstraction from concrete Web service implementations to high-level service models, which leads to more flexible and automated adaptations through template designs and transformations. The ontological semantics enhances the service matching capabilities required by the dynamic adaptation process. Service templates are based on OWL-S descriptions and provide the necessary means to capture and parameterize specific behavior patterns of service models. In this paper, we apply our approach in the context of the EU-funded ALIVE project and illustrate, as an example, how the proposed framework supports the adaptation of the authentication mechanism used by an interactive tourist recommendation system.