132,473 research outputs found
Pattern-based software architecture for service-oriented software systems
Service-oriented architecture is a recent conceptual framework for service-oriented software platforms. Architectures are of great importance for the evolution of
software systems. We present a modelling and transformation technique for service-centric distributed software systems. Architectural configurations, expressed through hierarchical architectural patterns, form the core of a specification and transformation technique. Patterns on different levels of abstraction form transformation invariants that structure and constrain the transformation
process. We explore the role that patterns can play in architecture transformations in terms of functional properties, but also non-functional quality aspects
Flexible Service Choreography
Service-oriented architectures are a popular architectural paradigm for building software
applications from a number of loosely coupled, distributed services. Through a
set of procedural rules, workflow technologies define how groups of services coordinate
with one another to achieve a shared task. A problem with workflow specifications
is that often the patterns of interaction between the distributed services are too complicated
to predict and analyse at design-time. In certain cases, the exact patterns of
message exchange and the concrete services to call cannot be predicted in advance, due
to factors such as fluctuating network load or the availability of services. It is a more
realistic assumption to endow software components with the ability to make decisions
about the nature and scope of their interactions at runtime.
Multiagent systems offer a complementary paradigm: building software applications
from a number of self interested, autonomous agents. This thesis presents an investigation
into fusing the agency and service-oriented architecture paradigms, in order
to facilitate flexible, workflow composition. Our approach offers an agent-based solution
to service choreography and is founded on the concept of shared interaction
protocols. By adopting an agent-based approach to service choreography, active autonomous
agents can utilise the typically passive service-oriented architectures, found
in Internet and Grid systems. In contrast with statically defined, centralised service
orchestrations, decentralised agents can perform service choreography at runtime, allowing
them to operate in scenarios where it is not possible to define the pattern of
interaction in advance.
Application to real scenarios is a driving factor behind this research. By working
closely with a number of active Grid projects, namely AstroGrid and the Large-Synoptic
Survey Telescope (LSST), a concrete set of requirements for scientific workflow have
been derived, based on realistic science problems. This research has resulted in the
MultiAgent Service Choreography (MASC) language to express scientific workflow,
methodology for system building and a software framework which performs agent based
Web service choreography, in order to enact distributed e-Science experiments.
Evaluation of this thesis is conducted through case study, applying the language, methodology
and software framework to solve a motivating set of workflow scenarios
Quality-aware model-driven service engineering
Service engineering and service-oriented architecture as an integration and platform technology is a recent approach to software systems integration. Quality aspects
ranging from interoperability to maintainability to performance are of central importance for the integration of heterogeneous, distributed service-based systems. Architecture models can substantially influence quality attributes of the implemented software systems. Besides the benefits of explicit architectures on maintainability and reuse, architectural constraints such as styles, reference architectures and architectural patterns can influence observable software properties such as performance. Empirical performance evaluation is a process of measuring and evaluating the performance of implemented software. We present an approach for addressing the quality of services and service-based systems at the model-level in the context of model-driven service engineering. The focus on architecture-level models is a consequence of the black-box
character of services
Towards a re-engineering method for web services architectures
Recent developments in Web technologies – in particular
through the Web services framework – have greatly enhanced the flexible and interoperable implementation of service-oriented software architectures. Many older Web-based and other distributed software systems will be re-engineered to a Web services-oriented platform. Using an advanced
e-learning system as our case study, we investigate central aspects of a re-engineering approach for the Web services platform. Since our aim is to provide components of the legacy system also as services in the new platform, re-engineering to suit the new development paradigm is as important as re-engineering to suit the new architectural requirements
Ontology-based patterns for the integration of business processes and enterprise application architectures
Increasingly, enterprises are using Service-Oriented Architecture (SOA) as an approach to Enterprise Application Integration (EAI). SOA has the potential to bridge
the gap between business and technology and to improve the reuse of existing applications and the interoperability with new ones. In addition to service architecture
descriptions, architecture abstractions like patterns and styles capture design knowledge and allow the reuse of successfully applied designs, thus improving the quality of
software. Knowledge gained from integration projects can be captured to build a repository of semantically enriched, experience-based solutions. Business patterns identify the interaction and structure between users, business processes, and data.
Specific integration and composition patterns at a more technical level address enterprise application integration and capture reliable architecture solutions. We use an
ontology-based approach to capture architecture and process patterns. Ontology techniques for pattern definition, extension and composition are developed and their
applicability in business process-driven application integration is demonstrated
Semantic model-driven development of service-centric software architectures
Service-oriented architecture (SOA) is a recent architectural paradigm that has received much attention. The prevalent focus on platforms such as Web services, however, needs to be complemented by appropriate software engineering methods. We propose the model-driven development of service-centric software systems. We present in particular an investigation into the role of enriched semantic modelling for a modeldriven development framework for service-centric software systems. Ontologies as the foundations of semantic modelling and its enhancement
through architectural pattern modelling are at the core of the proposed approach. We introduce foundations and discuss the benefits and also the challenges in this context
Service architecture design for E-Businesses: A pattern-based approach
E-business involves the implementation of business processes over the Web. At a technical level, this imposes an application integration problem. In a wider sense, the integration of software and business levels across organisations becomes a significant challenge. Service architectures are an increasingly adopted architectural approach for solving Enterprise Applications Integration
(EAI). The adoption of this new architectural paradigm requires adaptation or creation of novel methodologies and techniques to solve the integration problem. In this paper we present the pattern-based techniques supporting a methodological framework to design service architectures for EAI. The techniques are used for services identification, for transformation from business models to service architectures and for architecture modifications
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