scholarly journals Dissemination Protocols for Event-Based Service-Oriented Architectures

2008 ◽  
Vol 1 (3) ◽  
pp. 155-168 ◽  
Author(s):  
Brahim Medjahed
Author(s):  
Valentin Cristea ◽  
Ciprian Dobre ◽  
Corina Stratan ◽  
Florin Pop

This chapter introduces the macroscopic views on distributed systems’ components and their inter-relations. The importance of the architecture for understanding, designing, implementing, and maintaining distributed systems is presented first. Then the currently used architectures and their derivatives are analyzed. The presentation refers to the client-server (with details about Multi-tiered, REST, Remote Evaluation, and Code-on-Demand architectures), hierarchical (with insights in the protocol oriented Grid architecture), service-oriented architectures including OGSA (Open Grid Service Architecture), cloud, cluster, and peer-to-peer (with its versions: hierarchical, decentralized, distributed, and event-based integration architectures). Due to the relation between architecture and application categories supported, the chapter’s structure is similar to that of Chapter 1. Nevertheless, the focus is different. In the current chapter, for each architecture the model, advantages, disadvantages and areas of applicability are presented. Also the chapter includes concrete cases of use (namely actual distributed systems and platforms), and clarifies the relation between the architecture and the enabling technology used in its instantiation. Finally, Chapter 2 frames the discussion in the other chapters, which refer to specific components and services for large scale distributed systems.


2021 ◽  
Vol 15 (2) ◽  
pp. 1-25
Author(s):  
Amal Alhosban ◽  
Zaki Malik ◽  
Khayyam Hashmi ◽  
Brahim Medjahed ◽  
Hassan Al-Ababneh

Service-Oriented Architectures (SOA) enable the automatic creation of business applications from independently developed and deployed Web services. As Web services are inherently a priori unknown, how to deliver reliable Web services compositions is a significant and challenging problem. Services involved in an SOA often do not operate under a single processing environment and need to communicate using different protocols over a network. Under such conditions, designing a fault management system that is both efficient and extensible is a challenging task. In this article, we propose SFSS, a self-healing framework for SOA fault management. SFSS is predicting, identifying, and solving faults in SOAs. In SFSS, we identified a set of high-level exception handling strategies based on the QoS performances of different component services and the preferences articled by the service consumers. Multiple recovery plans are generated and evaluated according to the performance of the selected component services, and then we execute the best recovery plan. We assess the overall user dependence (i.e., the service is independent of other services) using the generated plan and the available invocation information of the component services. Due to the experiment results, the given technique enhances the service selection quality by choosing the services that have the highest score and betters the overall system performance. The experiment results indicate the applicability of SFSS and show improved performance in comparison to similar approaches.


Author(s):  
JENS WEBER-JAHNKE

Computer-based clinical decision support (CDS) contributes to cost savings, increased patient safety and quality of medical care. Most existing CDS systems are stand-alone products (first generation) or part of complete electronic medical record packages (second generation). Experience shows that creating and maintaining CDS systems is expensive and requires effort that should be economized by sharing them among multiple users. It makes good economic sense to share CDS service installations among a larger set of client systems. The paradigm of a service-oriented architecture (SOA) embraces this idea of sharing distributed services. Some attempts making CDS services available to distributed health information systems exist. However, these approaches have not gained much adoption. We argue that they do not provide a sufficient level of decoupling between client and CDS in order to be broadly reusable in SOAs. In this paper, we present a new CDS service component called EGADSS, which has been designed and implemented with the declared objective to minimize the coupling between client and CDS server. We present our key design decisions, which are guided by empirical research in SOA development. We evaluate our result theoretically by measuring the level of decoupling achieved compared to existing CDS approaches. Furthermore, we report on an empirical evaluation of the resulting design, integrating the EGADSS service with an example client system.


2008 ◽  
Vol 2 (2) ◽  
pp. 1-46 ◽  
Author(s):  
Seung Hwan Ryu ◽  
Fabio Casati ◽  
Halvard Skogsrud ◽  
Boualem Benatallah ◽  
Régis Saint-Paul

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