Vina Ermagan

Rich Services: The Integration Piece of the SOA Puzzle

One of the key challenges to successful systems-of- systems integration using Web services technologies is how to address crosscutting architectural concerns such as policy management, governance, and authentication, while still maintaining the lightweight implementation and deployment flavor that distinguishes Web services from earlier attempts at providing interoperable enterprise systems. To address this challenge, this article introduces the notion of a Rich Service, an extension of the standard service notion, based on an architectural pattern that allows hierarchical decomposition of system architecture according to separate concerns. Rich Services enable the capture of different system aspects and their interactions. By leveraging emerging Enterprise Service Bus technologies, Rich Services also enable a direct transition from a logical to a deployed service-oriented architecture (SOA). This results in immediate benefits not only in SOA design, implementation, deployment, and quality assurance, but also in the traceability of architectural requirements to an SOA implementation.

A UML2 profile for service modeling

In this article we provide an embedding of an interaction-based service notion into UML2. Such an embedding is needed, because to this date, UML2 has only limited support for services - they are certainly not first-class modeling elements of the notation. This is despite the ever increasing importance of services as an integration paradigm for ultra large scale systems. The embedding we provide rests on two observations: (i) services are fundamentally defined by component collaborations; (ii) to support a seamless development process, the service notion must span both logical and deployment architecture. To satisfy (i) and (ii) we introduce modifications to the UML that focus on interaction modeling, and the mapping from logical to deployment service architectures. The result is a novel and comprehensive UML2 profile for service-oriented systems.

A Fault Tolerance Approach for Enterprise Applications

Service oriented architectures (SOAs) have emerged as a preferred solution to tackle the complexity of large-scale, complex, distributed, and heterogeneous systems. Key to successful operation of these systems is their reliability and availability. In this paper, we propose an approach to creating fault tolerant SOA implementations based on an architectural pattern called Rich Services. Our approach is model-driven, focuses on interaction specifications as the means for defining services and managing their failures, and is technology independent. We leverage an enterprise service bus (ESB) framework to implement a system based on the fault tolerant Rich Service pattern. We evaluate our approach by measuring availability and reliability of an experimental system in the e-business domain.

A Rich Services Approach to CoCoME

Systems-of-systems integration projects present exquisite challenges for software and systems engineering researchers and practitioners. Traditional integration approaches involve time-consuming rework bearing major financial and technical risk. Service-Oriented Architectures (SOAs) have emerged as a widely accepted solution to this challenge because they use standards-based infrastructure to forge large-scale systems out of loosely-coupled, interoperable services. SOAs can create systems-of-systems by mapping existing systems into services, then orchestrating communication between the services. New functionality can be created by either adding new services or modifying communication among existing services. Because of these features, SOA projects are particularly amenable to agile development processes. Consequently, well executed SOAs can drive down financial and technical risk by improving flexibility and reducing time to market.

Aspect-oriented modeling approach to define routing in enterprise service bus architectures

System-of-systems integration is a fundamental challenge to Software Engineering. Enterprise Service Bus (ESB) technologies help overcoming this challenge by addressing loose coupling of services while provisioning for crosscutting concerns. ESBs use aspect-oriented techniques and flexible message routing and filtering to support decoupling of the business logic from crosscutting concerns such as encryption and failure management. These characteristics have led to an increasing adoption of ESBs in the enterprise business domain. However, currently there is no systematic development approach for Service-Oriented Architectures (SOAs) ranging from requirements analysis to architecture design to ESB deployment. A core challenge is the precise specification of the routing capabilities of the ESB. A viable solution should maintain the decoupling of crosscutting concerns from the business logic while being able to reason about the integrated interaction pattern. In this paper we leverage the Rich Service architectural blueprint in combination with Aspect-Oriented Modeling techniques to address this problem.

A Service-Oriented Blueprint for COTS Integration: the Hidden Part of the Iceberg

The use of commercial off-the-shelf (COTS) software can greatly reduce the development cost and effort for complex software systems. Reusing software can also improve the general quality of a system by leveraging already proven implementations. One of the limiting factors in the adoption of COTS software is the complexity of integrating it with the rest of the system under development. Often, requirements do not entirely match the functionalities available in COTS components, increasing the complexity of the glue software that needs to be written. In this paper, we present the blueprint of a service-oriented architecture that can guide the engineer both in specifying the functionalities of a complex software system and as a deployment architecture to seamlessly integrate COTS components implementing such functionalities. The COTS integration concern, typically a deployment issue, is addressed in the service architecture, and is treated as first-class citizen of the development process.

Rich services: addressing challenges of ultra-large-scale software-intensive systems

Ultra-Large-Scale (ULS) Software-Intensive Systems are the new frontier for Software Engineering research and development. The requirements space for ULS encompasses, in particular, the system-of-systems integration challenge. This challenge is characterized by the inherently distributed nature of the constituent systems and the integration solution, the typically interdisciplinary back-ground from which these constituent systems emerge, the need to address a broad spectrum of crosscutting concerns as part of the integration fabric, and a significant amount of agility both in the integration architecture and the development process to accommodate changing requirements over time. In this position paper, we discuss some of the consequences we see emerging from this challenge, propose an architectural blueprint for addressing them, and present future research directions.