Policy-based web service composition

Distributed and Parallel …, 2005

This paper describes a knowledge-based Web Service composition system, called SWIM, which is based on the Service Domain model. Service Domains are communities of related Web Services that are mediated by a single Web Service, called the Mediator Service, which functions as a proxy for them. When a requestor sends a message to the Mediator Service one or more of the related Web Services are selected to dispatch the message and the results returned are aggregated to a single answer to the requestor. Mediator Services can be further composed to more complex Mediator Services that combine several selection and aggregation algorithms among many heterogeneous web services. The system utilizes the X-DEVICE deductive XML rule language for defining complex algorithms for selecting registered web services, combining the results, and synchronizing the workflow of information among the combined web services in a declarative way. In the paper, we demonstrate the flexibility and expressibility of our approach for composing Web Services using several e-business examples, covering most of the workflow patterns found in a comprehensive workflow management system [2].

2006

Abstract Simplifying the discovery of web services on one hand and protecting them from misuse on the other hand has initiated several lines of research in the area of policyaware semantic web services. However, the diversity of approaches, ontologies and languages chosen for defining Semantic Web services and policies has made the research area cluttered. It is now ambiguous how different registries and agents with different policy languages and Semantic Web service ontologies would share their information.

Aaai fall symposium on agents and the …, 2005

Workflow templates are necessary for various different Web Service related tasks such as encoding business rules in a B2B application, specifying domain knowledge in a scientific Grid application, and defining preferences for users that interact with Web Services. Abstract activities in templates can be used to specify the features of a required service and concretes service can be discovered and used to generate executable workflows. In this paper, we examine how Web ontologies can be used to write such template descriptions that will allow flexible matchmaking of services. We discuss the importance of expressing preferences in templates and provide a ranking algorithm based on DL inference services. We then present the HTN-DL formalism -an extension to the HTN planning formalism to generate compositions of Web Services based on these templates. Finally we present the experimental evaluation for the composition system we proposed.

2008

In this work, we present a framework for the semantic composition of web services based on Statecharts and uniform community service descriptions. Our model is a two step process. In the first step, we derive the execution model of the user's query. The execution model is specified in Statecharts formalism; whereas the user's query is described in OWL-S. Therefore, a mapping from Statecharts formalism to OWL-S is developed. In the second step, we instantiate the developed execution model through invocation of available e-services instances. Hence, and a result, we obtain an execution plan (said also strategy) satisfying user constraints. The key features of the proposed framework could be summarized as follows. First, unlike other existing languages, using OWL-S enables the semantic description of e-services. These semantics are taken into consideration in our composition strategy. Second, the user constraints (or preferences) are taken into account during composition and are expressed as a finite set of logical formulas with the Knowledge Interchange Format (KIF) language.

Web services technologies are becoming a de facto standard to integrate distributed applications and systems. Developing applications that support web services interfaces will not be enough to provide complete and coordinated business processes. Thus, we need a new approach to compose these web services together in order to form composite web services. Once a Web service is published and deployed, other applications can discover and invoke it. Business domains have requirement for automatically composing web services according to specified business logic which requires an efficient way of selecting web service according to component requirement. In this paper, we present an approach for automatically composing Web Services into composite service by using ontology for semantic description.

2018

A Web service is a collection of open protocols and standards used for exchanging data between applications and systems. Web Service discovery, selection and composition are the important tasks of the any automated business processes. In a web service composition set of web services are collectively executed to achieve the objectives. This study reveals the existing approaches used for web service composition in both syntactic and semantic environments. We have reviewed more than 40 articles in this domain and concluded with merits and demerits of the methodologies applied for the implementation of the web service composition.

Qubahan Academic Journal, 2021

Abstract—Service composition is gaining popularity because a composite service can perform functions that an individual service cannot. There are multiple web services available on the web for different tasks. The semantic web is an advanced form of the current web in which all contents have well-defined meanings due to nature, allowing machines to process web contents automatically. A web service composition is a collection of web services that collaborate to achieve a common goal. They reveal the established methods for web service composition in both syntactic and semantic environments. In this study Initially, we identify the existing techniques used for the composition. We classified these approaches according to the processing of the service descriptions, which can be syntactic or semantic-based service processes. We have reviewed more than 14 articles in this domain and concluded the merits of the methodologies applied for the implementation of web service composition.

Service Oriented Computing and Applications, 2014

With the increasing popularity of Web Services and Service-Oriented Architecture, we need infrastructure to discover and compose Web services. In this paper, we present a generalized semantics-based technique for automatic service composition that combines the rigor of processoriented composition with the descriptiveness of semantics. Our generalized approach presented in this paper introduces the use of a conditional directed acyclic graph where complex interactions, containing control flow, information flow, and pre-/post-conditions are effectively represented. Composition solution obtained is represented semantically as OWLS documents. Web service composition will gain wider acceptance only when users know that the solutions obtained are comprised of trustworthy services. We present a framework that not only uses functional and non-functional attributes provided by the Web service description document but also filters and ranks solutions based on their trust rating that is computed using Centrality Measure of Social Networks. Our contributions are applied for automatic workflow generation in context of the currently important bioinformatics domain. We evaluate our engine for automatic workflow generation of a phylogenetic inference task. We also evaluate our engine

Lecture Notes in Computer Science, 2003

The successful application of Grid and Web Service technologies to real-world problems, such as e-Science [1], requires not only the development of a common vocabulary and meta-data framework as the basis for inter-agent communication and service integration but also the access and use of a rich repository of domain-specific knowledge for problem solving. Both requirements are met by the respective outcomes of ontological and knowledge engineering initiatives. In this paper we discuss a novel, knowledge-based approach to resource synthesis (service composition), which draws on the functionality of semantic web services to represent and expose available resources. The approach we use exploits domain knowledge to guide the service composition process and provide advice on service selection and instantiation. The approach has been implemented in a prototype workflow construction environment that supports the runtime recommendation of a service solution, service discovery via semantic service descriptions, and knowledge-based configuration of selected services. The use of knowledge provides a basis for full automation of service composition via conventional planning algorithms. Workflows produced by this system can be executed through a domain-specific direct mapping mechanism or via a more fluid approach such as WSDL-based service grounding. The approach and prototype have been used to demonstrate practical benefits in the context of the Geodise initiative [2].

Measuring Outcomes and Effectiveness

This chapter presents a comprehensive logic programming framework designed to support intelligent composition of Web services. The underlying model relies on the modeling of Web services as actions, each described by a logic programming theory. This view allows the use of logic-based planning to address the Web service composition problem, taking advantage of the fact that logic-based planning enables the elegant introduction of a number of extensions and generalizations (e.g., dealing with incomplete knowledge and preferences). The theory describing each Web service is encoded as a logic programming module, and different semantics are allowed within different modules, thus better reflecting the practical use of different service description formalisms and ontologies.