Dynamic Web Service Composition Research Articles

Dynamic composition and optimization of Web services

Process-based composition of Web services has recently gained significant momentum for the implementation of inter-organizational business collaborations. In this approach, individual Web services ...

A reference model for dynamic web service composition systems

Web services have become an emerging and promising technology to design and build complex business applications out of atomic web-based software components. To enforce extensive software reuse and dynamic adaptation, dynamic service composition has experienced an increasing interest in research efforts. Together, the lack of a general conceptual reference model for dynamic web service composition systems and the widespread use of these systems in service-enabled applications constitute a problem of management for these systems. To capture the requirements and challenges of these composition systems, a survey of a representative set of these systems is presented. In this paper, we develop a reference model for describing the functional structure and evaluating the performance of dynamic web service composition systems based on existing dynamic web service composition platforms and prototypes. To the best of our knowledge there has been no such model in the literature.

A business model for dynamic composition of telecommunication web services

Web service composition is a mechanism for creating new web services from existing Web services. Web service composition enables rapid service creation by reusing existing services. Dynamic composition is composition at runtime. A business model defines the different parties involved in service provisioning and their relationships. However, the existing business models are not suitable for Web service composition. This article proposes a novel business model for dynamic web service composition that is an extension of the standard web service business model. The proposed model is demand-driven, where services can be dynamically composed based on the demand for them. We introduce new business roles and new interactions. We have provided a UDDI-based implementation of our new model by proposing extensions to the subscription API of UDDI. We have developed a proof-of-concept prototype, and have made some preliminary performance measurements. The performance analysis shows that the UDDI extensions incur acceptable performance penalization.

Adaptive web service composition

Web services have played an important role in the development of distributed systems. In particular, the possibility of composing already implemented web services in order to provide a new functionality is an interesting approach for building distributed applications and business processes. The possibility of dynamically composing web services is also apparent. Current approaches address to this point, but they do not adopt established specifications, like WS-BPEL, as they usually propose modifications in the rules of business process specifications by imposing more difficulties to implement the system. This paper proposes a policy-driven approach for enabling web service adaptability through a semantic modification in the invocation primitive of WS-BPEL, whilst mantains its syntax unaffected. Hence, programmers may define dynamic web service compositions without changing the source code. The approach has been applied to a loan approval system in order to illustrate it.

Dynamic web service composition based on OWL-S

Composing existing web services for enterprise applications may enable higher level of reuse. However the composition processes are mostly static and lack of support for runtime redesign. In this paper, we describe our approach to the extension of the OWL-S ontology framework for dynamic web service composition. We raise the level of abstraction and propose an abstract service layer so that web services can be composed at the abstract service level instead of the concrete level. Each abstract service is attached with an instance pool including all instances of the abstract service to facilitate fail-over and dynamic compositions.

APPLYING ORCHESTRATION AND CHOREOGRAPHY OF WEB SERVICES ON DYNAMIC VIRTUAL MARKETPLACES

The Service-Oriented Architecture promises to be an affordable solution for the integration of heterogeneous systems through the Internet. In the e-Business field, this promise represents a great chance for companies to increase competitiveness and to enable the enactment of new collaborative e-Business processes. In this paper, we present a Virtual Marketplace infrastructure, the VM-Flow, which uses Dynamic Composition of Web Services (Orchestration and Choreography) as a fundamental technique to enable interorganizational business interactions in the context of Dynamic Virtual Enterprises. The VM-Flow platform is workflow-based and also introduces a series of interaction policies to deal with aspects like autonomy and privacy. A platform model is presented together with details on the infrastructure prototype and on an application built over it.

Classification of the state-of-the-art dynamic web services composition techniques

Dynamic web service composition can serve applications or users on an on-demand basis. With dynamic composition, the application's capabilities can be extended at runtime so that theoretically an unlimited number of new services can be created from a limited set of service components, thus making applications no longer restricted to the original set of operations specified and envisioned at design and/or compile time. Moreover, dynamic composition is the only means to adapt the behaviour of running components in highly available applications such as, banking and telecommunication systems where services cannot be brought offline to upgrade or remove obsolete services. In this paper, we present a novel classification of the current state-of-the-art dynamic web services composition techniques with attention to the capabilities and limitations of the underlying approaches. The proposed taxonomy of these techniques is derived based on a comprehensive survey of what has been done so far in dynamic web service composition. Finally, we summarise our findings and present a vision for future research work in this area.

Dynamic web service composition with QoS constraints

In service oriented systems, complex applications can be composed as business processes invoking a variety of available web services with different characteristics. Usually, a set of functionally equivalent services can be selected, that is, services which implement the same functionality but differ for quality parameters. Under this scenario, applications are defined as high level business processes and service composition can be implemented dynamically by identifying the best set of services available at run time satisfying also Quality of Service (QoS) constraints. In this paper, we model the service composition problem as a mixed integer linear problem where local constraints, that is, constraints for component web services, and global constraints, that is, constraints for the whole application, can be specified. Our approach proposes the formulation of the optimisation problem as a global ptimisation. Constraints are fulfilled statically at deployment time and are guaranteed at run time through dynamic reoptimisation. Experimental results demonstrate the effectiveness of our approach.

동적 웹 서비스 조합을 위한 시멘틱 웹 서비스 발견 및 실행 기법

최근에 동적으로, 즉 요구가 있는 즉시 서비스들을 조합하는 동적 웹 서비스 조합은 가장 큰 관심사 중 하나이다. 지금까지 동적 웹 서비스조합에 관한 많은 연구들이 수행되어졌는데 주로 사람이 개입된 반자동 대화식 조합 기법들이 제안되었다. 또한 이들 연구에서 탐색 알고리즘 및 워크플로우 설계 기법들이 부분적으로는 기술되어 있으나. 웹 서비스 조합 자동화를 위한 전반적인 워크플로우 처리과정을 기술한 연구는 아직 없다. 본 논문은 웹 서비스 조합 자동화 기법에 초점을 맞추고 있다. 주된 아이디어는 시멘틱 웹을 실현하기 위한 웹 온톨로지와 비즈니스분야에서 성공적으로 활용되고 있는 워크플로우 기법들을 적용하여 웹 서비스 조합 자동화 시스템을 구현하는 것이다. 본 연구에서는 웹 서비스발견을 위해 매칭 알고리즘이 제안되고, 웹 서비스들 간 상호연결을 지원하기 위해 매칭 알고리즘에 온톨로지 개념이 적용된다. 그리고 웹 서비스 조합 자동화를 지원하기 위한 워크플로우 실행계획이 기술된다. 마지막으로 실 데이터 실험을 통해 제안 시스템의 우수성을 보인다. Recently, one of the most challenging problems is to compose web services dynamically, that is, on demand. A number of researchers have been considerably interested in the dynamic web services composition. However, while most of them focused on the semi-automatic web services composition with a human controller, very little attention was devoted to the full automation of this process. This paper primarily focuses on the automatic web services composition techniques. The main idea is to implement an automatic web services composition system using web ontologies to realize the semantic web and workflow technologies to play a major role in E-businesses. In this paper, we propose a matching algorithm for web service discovery and present an approach based on the use of ontologies to facilitate the interoperability of web services. Finally, we describe a workflow execution plan to support the automatic web services composition, and an experimental study that shows the high performance of our system.

A FRAMEWORK FOR ADAPTIVE AND DYNAMIC COMPOSITION OF WEB SERVICES

The modularity of web services has left an open problem in composition, a scenario that involves an amalgamation of two or more web services to fulfill a request that no one web service is able to provide. This paper presents a framework for adaptive and dynamic composition of web services, enabling web services to be discovered either statically or dynamically by utilizing a semantic ontology to describe web services and their methods. This novel approach gives greater control on how web services are dynamically discovered by allowing the application developer to specify how matches are made, which goes beyond the present techniques of semantically matching inputs and outputs along with classification taxonomies. We utilize the Composite Capabilities/Preferences Profiles (CC/PP) to adapt the interface and content to be compatible with virtually any device. A proof of concept implementation has been constructed that enables users of any device to dynamically discover context-based services that will be dynamically composed to satisfy a user's request. In addition, we have designed and implemented a UDDI-like registry to support context-based adaptive composition of web services. Existing web services can be easily adapted and new web services can be effortlessly deployed.

Dynamic and Personalized Web Services Composition in E-Business

Building composite Web services can save significant time and cost for developing new applications and enhancing the interoperability and collaboration among E-business partners. This article proposes a framework for dynamic and personalized composition of Web services using an approach that integrates not only functional attributes of Web services, but also nonfunctional attributes such as service requirements, quality of service, and the preferences and constraints of individual service consumers. A prototype system based on the proposed framework and some implementation details are also presented.

Non-Backtrace Backward Chaining Dynamic Composition of Web Services Based on Mediator

Non-Backtrace Backward Chaining Dynamic Composition of Web Services Based on Mediator

Cohesion Metrics for Ontology Design and Application

Recently, domain specific ontology development has been driven by research on the Semantic Web. Ontologies have been suggested for use in many application areas targeted by the Semantic Web, such as dynamic web service composition and general web service matching. Fundamental characteristics of these ontologies must be determined in order to effectively make use of them: for example, Sirin, Hendler and Parsia have suggested that determining fundamental characteristics of ontologies is important for dynamic web service composition. Our research examines cohesion metrics for ontologies. The cohesion metrics examine the fundamental quality of cohesion as it relates to ontologies.

Composing Web Services: A QoS View

An Internet application can invoke several services--a stock-trading Web service, for example, could invoke a payment service, which could then invoke an authentication service. Such a scenario is called a composite Web service, and it can be specified statically or established dynamically. Dynamic composition of Web services requires service consumers to discover service providers that satisfy given functional and nonfunctional requirements including cost and QoS requirements such as performance and availability. In previous columns, I've examined how quality of service (QoS) comes into play for service providers, consumers, and parallel transactions. Here, I'll show how it fits into composite Web services.

A declarative approach to composing web services in dynamic environments

A recent trend in E-business is the deployment of a variety of web services by product and service vendors to facilitate B2B and B2C E-commerce. To utilize these web services effectively, customer's have to (a) locate each of these services from service directories and retrieve brief service descriptions, (b) analyze service features and evaluate their applicability to the task at hand dynamically, and finally (c) invoke these services in a certain sequence to complete an overall business or personal need. Alternatively, intermediaries execute the aforementioned steps manually and provide a composite service for access from a single service platform. Both these approaches are highly tedious (either for the customer or intermediary) and non-scalable due to the volatility and size of the web. The dynamic nature of the availability and features of web services, real-time requirements on service composition and the large number of alternative combinations of service choices to fulfill a service need makes major demands on the service composition process. This paper presents a novel declarative approach to facilitate dynamic and scalable web service composition called Integrated Service Planning and Execution (ISP&E) based on AI planning techniques. Implementation of an architecture for dynamic web service composition and execution based on a domain-independent AI planning framework called Hierarchical Task Network (HTN) planning is described in this paper. Simulated experiments highlight the effectiveness of our proposed approach which interleaves service composition and execution, to cope with dynamic service capabilities and service volatility.

Towards a Framework for Agent-Enabled Semantic Web Service Composition

The article presents the framework for agent-enabled dynamic Web service composition. The core of the methodology is the new understanding of a Web service as an agent capability having proper ontological description. It is demonstrated how diverse Web services may be composed and mediated by dynamic coalitions of software agents collaboratively performing tasks for service requestors. Middle Agent Layer is introduced to conduct service request to task transformation, agent-enabled cooperative task decomposition and performance. Discussed are the formal means to arrange agents’ negotiation, to represent the semantic structure of the task-activity-service hierarchy and to assess fellow-agents’ capabilities and credibility factors. Finally, it is argued that the presented formal technique is applicable to various application domains. Presented is the ongoing work on designing and implementing agent-based layered architecture for intelligent rational information and document retrieval. Finally, the discussion of the OntoServ.Net framework for the development of P2P mobile service infrastructures for industrial asset management provides the extension of the Web service composition approach.

Modeling the Flow in Dynamic Web Services Composition

Modeling the Flow in Dynamic Web Services Composition

Multiagent systems with workflows

Industry and researchers have two different visions for the future of Web services. Industry wants to capitalize on Web service technology to automate business processes via centralized workflow enactment. Researchers are interested in the dynamic composition of Web services. We show how these two visions are points in a continuum and discuss a possible path for bridging the gap between them.