Services and Service Composition – An Introduction (Services und Service Komposition – Eine Einführung)

2008 ◽  
Vol 50 (2) ◽  
Author(s):  
Shahram Dustdar ◽  
Mike P. Papazoglou

SummaryIn this overview paper, we discuss the basic principles underlying service-oriented computing in general, and (Web) services in particular. We discuss the important differences between (Web) services and Web applications and other models in Internet computing. Finally, we discuss where we see the future research challenges in the area of service composition.

2007 ◽  
pp. 244-267
Author(s):  
Bernd Aman ◽  
Salima Benbernou ◽  
Benjamin Nguyen

Unlike traditional applications, which depend upon a tight interconnection of all program elements, Web service applications are composed of loosely coupled, autonomous and independent services published on the Web. In this chapter, we first introduces the concept of service oriented computing (SOC) on the Web and the current standards enabling the definition and publication of Web services. This technology’s next evolution is to facilitate the creation and maintenance of Web applications. This can be achieved by exploiting the self-descriptive nature of Web services combined with more powerful models and languages for composing Web services. A second objective of this chapter is to illustrate the complexity of the Web service composition problem and to provide a representative overview of the existing approaches. The chapter concludes with a short presentation of two research projects exploiting and extending the Web service paradigm.


Author(s):  
Abul Ahsan Md Mahmudul Haque ◽  
Weihai Yu

Web mashups are web applications built on top of external web services through their open APIs. As mashups are becoming increasingly complex, there is a need for systematic support for their development and orchestration. This paper presents a peer-to-peer approach to mashup orchestration where a network of agents carries out orchestration using continuation-passing messaging. The approach supports exception handling and recovery. Our experimental results show clear performance gains of the approach over traditional centralized orchestration in service-oriented computing and orchestration done by application servers hosting mashups.


Author(s):  
Clarissa Cassales Marquezan ◽  
Andreas Metzger ◽  
Klaus Pohl ◽  
Vegard Engen ◽  
Michael Boniface ◽  
...  

Adaptive capabilities are essential to guarantee the proper execution of Web services and service-oriented applications once dynamic changes are not exceptions but the rule. The importance of adaptive capabilities significantly increases in the context of Future Internet (FI) applications will have to autonomously adapt to changes on service provisioning, availability of things and content, computing resources, and network connectivity. Current solutions for adaptive Web services and adaptive service-based applications will be challenged in such a setting because they fall short to support essential characteristics of FI applications. This chapter analyzes and justifies the need for the transition from adaptive Web services and service-based applications to adaptive FI applications. Based on two real-world use cases from multimedia and logistics, the authors examine where current solutions fall short to properly address the adaptive needs of FI applications. They propose future research challenges that should be considered in adaptive FI applications.


Author(s):  
Clarissa Cassales Marquezan ◽  
Andreas Metzger ◽  
Klaus Pohl ◽  
Vegard Engen ◽  
Michael Boniface ◽  
...  

Adaptive capabilities are essential to guarantee the proper execution of Web services and service-oriented applications once dynamic changes are not exceptions but the rule. The importance of adaptive capabilities significantly increases in the context of Future Internet (FI) applications will have to autonomously adapt to changes on service provisioning, availability of things and content, computing resources, and network connectivity. Current solutions for adaptive Web services and adaptive service-based applications will be challenged in such a setting because they fall short to support essential characteristics of FI applications. This chapter analyzes and justifies the need for the transition from adaptive Web services and service-based applications to adaptive FI applications. Based on two real-world use cases from multimedia and logistics, the authors examine where current solutions fall short to properly address the adaptive needs of FI applications. They propose future research challenges that should be considered in adaptive FI applications.


Author(s):  
Mihai Horia Zaharia

Highly developed economies are based on the knowledge society. A variety of software tools are used in almost every aspect of human life. Service-oriented architectures are limited to corporate-related business solutions. This chapter proposes a novel approach aimed to overcome the differences between real life services and software services. Using the design approaches for the current service-oriented architecture, a solution that can be implemented in open source systems has been proposed. As a result, a new approach to creating an agent for service composition is introduced. The agent itself is created by service composition too. The proposed approach might facilitate the research and development of Web services, service-oriented architectures, and intelligent agents.


Author(s):  
Fahad Aijaz

The Information Technology (IT) and Telecommunication (TelCo) sectors face enormous integration challenges, due to the prominent heterogeneity in existing systems. Service-oriented computing tackles such challenges by providing a fundamental platform that facilitates the convergence of distinct domains based on Web Services (WSs). With the mobility and technological advancements, service-oriented computing has been pushed towards the mobile sector enabling P2P Mobile Web Services (MobWSs) provisioning. In this work, we investigate the interaction, architecture and design characteristics of MobWSs for P2P computing. Here, the two MobWS interaction strategies are presented followed by the architectural discussion, enfolding server and client side components, of a resource-oriented MobWS framework. We follow REST design principles to propose an efficient way of architecting P2P MobWS systems, as an alternative to SOAP, enabling significant payload reduction and performance optimization in mobile servers. The detailed performance evaluation is also presented and compared to SOAP based on real-time measurements. By analyzing performance characteristics, we show that REST is a promising technique to architect P2P MobWS systems for resource-constraint mobile nodes.


Author(s):  
Stéphanie Chollet ◽  
Philippe Lalanda ◽  
Jonathan Bardin

The visionary promise of Service-Oriented Computing (SOC) is a world-scale network of loosely coupled services that can be assembled with little effort in agile applications that may span organizations and computing platforms. In practice, services are assembled in a Service-Oriented Architecture (SOA) that provides mechanisms and rules to specify, publish, discover and compose available services. The aim of this chapter is to present the different technologies implementing the new paradigm of SOA: Web Services, UPnP, DPWS, and service-oriented component OSGi and iPOJO. These technologies have been developed and adapted to multiple domains: application integration, pervasive computing and dynamic application integration.


2009 ◽  
pp. 279-289
Author(s):  
Emerson Loureiro ◽  
Frederico Bublitz ◽  
Loreno Oliveira ◽  
Nadia Barbosa ◽  
Angelo Perkusich ◽  
...  

The fast development on microelectronics has promoted the increase on the computational power of hardware components. On the other hand, we are facing a significant improvement on energy consumption as well as the reduction of the physical size of such components. These improvements and the emergence of wireless networking technologies are enabling the development of small and powered mobile devices. Due to this scenario, the so-called pervasive computing paradigm, introduced by Mark Weiser in 1991 (Weiser, 1991) is becoming a reality. Such a paradigm envisions a world where environments are inhabited by computing devices, all of them seamlessly integrated into peoples’ lives, and effectively helping to carry on their daily tasks. Among others, one major characteristic of Weiser’s vision is that each device in an environment becomes a potential client or provider of resources. Not surprisingly, pervasive computing environments are becoming dynamic repositories of computational resources, all of them available to mobile users from the palm of their hands. However, devices can unpredictably join and leave such environments. Thus, resources can be dynamically made available or unavailable. Such a scenario has a great impact on the way that resources are found and used. In the case of static environments, such as the Web, it is reasonable to look up and access resources, such as Web pages, knowing the address of their providers beforehand. On the other hand, for dynamic environments, such as the pervasive computing ones, this is not a reasonable approach. This is due to the fact that one cannot guarantee that the provider of a resource will be available at any moment, because it may have left the environment or simply turned off. A better approach would be to discover these resources based on their descriptions, or any other feature that does not require the client to know the specific address of their providers. To this end, some of the current pervasive computing solutions, like Wings (Loureiro, Bublitz, Oliveira, Barbosa, Perkusich, Almeida, & Ferreira, 2006), Green (Sivaharan, Blair, & Coulson, 2005), RUNES (Costa, Coulson, Mascolo, Picco, & Zachariadis, 2005), and Scooby (Robinson, Wakeman, & Owen, 2004), are making use of a novel approach from the branch of distributed applications, the service-oriented computing paradigm (Papazoglou, 2003; Huhns & Singh, 2005). This is due to the fact that such a paradigm provides a crucial element for pervasive computing systems, the ability for dynamically binding to remote resources (Bellur & Narenda, 2005), which enables mobile devices to find needed services on demand. However, pervasive environments may be structured in different ways. They can range from wired networks to completely wireless ones, where communication among the devices is performed in an ad hoc way. Such a characteristic indicates that the way services are provisioned in a pervasive computing environment should fit in its organization, in order to enhance the access to the services available. Considering the above discussion, in this article we provide a review on service provision and its applicability in pervasive computing. More precisely, we will list the existing service provision approaches and discuss the characteristics and problems associated with each one, as well as their usage in pervasive computing environments. We start by providing introductory concepts of service-oriented and pervasive computing, respectively in the service-oriented computing and pervasive computing sections. Next, we present the service provision techniques available and how they can be applied for pervasive computing environments. The main current solutions within this scope will be introduced in the service oriented technologies section. Some of the future trends associated with research for service provision in pervasive computing environments will be presented in the future research trends section. Finally, in the conclusions sect


2014 ◽  
Vol 11 (2) ◽  
pp. 67-84 ◽  
Author(s):  
Tanveer Ahmed ◽  
Abhishek Srivastava

Service oriented architecture has revolutionized the way a traditional business process is executed. The success of this architecture is Indue to the composition of multiple heterogeneous services at runtime. Web service composition is a mechanism where several web services are combined at runtime to build a complex application for a user. It is one of the most sought after processes in the context of semantic web. But, composition of web services at runtime is a difficult task owing to the availability of multiple service providers offering the same functionality. The process if exasperated by due conflicting preferences of a service consumer. In this paper, the authors address the issue of selecting a service based on Quality of Service (QoS) attributes. They utilize concepts customized from physics to create an environment that facilitates the selection of a best service from the set of similar services. The technique not only facilitates the selection of the service with the best QoS attributes, but distributes the load among expeditiously. Here in this paper, the authors concentrate on minimizing and equitably balancing the waiting time for a user. They conduct in silico experiments on multiple workflows to demonstrate the efficacy of the proposed technique to balance load efficiently among similar service offerings.


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