Reliability Of Composite Web Service Research Articles

Colored Petri Net Based Techniques for Constructing Reliable Web Service Composition

In today's scenario, there are many web services around the web. This service has its own limited functionality. A single service can not satisfy the users' requests, so we need to combine these services in a set of services. Web service composition uses certain standard protocol to provide these services such as UDDI, SOAP, and WSDL. Reliability of composite web service which is an important aspect. The analysis of reliability in this scenario is not an easy task. In this paper we have proposed a model named Coloured Petri net based Reliability in Composite Web Service (CPN-RCWS). Using this model we compared the reliability under different state of recovery mechanism.

A Reliable Automatic Service Composition Method Based on Type Theory

Web Service composition has become a critical technology to react to the complex functional requirements put forward by business logic in e-commerce. How to guarantee the reliability of composite Web service is a hot topic through all the phase of lifecycle, including design, development and deployment. To this end, we are motivated to propose a Type Theory (TT) based method to automatic service composition. First of all, a service model in form of TT representation defines the atomic services declarations, semantic relation and composition request. Then, a set of TT rules that helps to prove the satisfiability of the user’s request is formally given. Later, several useful tools transforming the service declaration files to the propositions and extracting the composition result from the proof is discussed. To face the challenge of reliability, we show a hybrid model, which dynamically binds service with the corresponding strict proving, to ensure the reliability of our method during compositing services. At last, the proposed method is implemented and a complete case study is conducted to demonstrate the applicability and effectiveness of our techniques.

A Literature Review of the Reliability of Composite Web Service in Service-Oriented Architecture

The demands of clients in context of business application have always been high in distributed environments. With these ever increasing demands there comes the requirement for change. Service-Oriented Architecture is an architecture style that is used for the development and integration of functionality of services provided by different stakeholders. To provide refined solutions for designing business enterprise, Service-Oriented Architecture approach is adopted without affecting overall functionality of organization. For designing a Service-Oriented Architecture, there are many quality attributes like reliability, flexibility, reusability and maintainability. Among of all these, reliability is a primary concern. This survey explains three important reliability models: state-base, path-based and additive model. This paper discusses some literature for composite reliability of Service-Oriented Architecture. For this literature we have selected research articles on Service-Oriented Architecture from 2005 to 2013.

Reliable Web service composition based on QoS dynamic prediction

Web service dynamic composition is a key technology for creating value-added services by composing available services and applications. With the rapid development of web service, cloud computing, big data and internet of things, more and more services with identical functionality and different Quality of Service (QoS) are available; moreover, QoS of Web services are highly dynamic, so, how to create composite Web services reliably and efficiently is still an open issue. For this problem, this paper proposes a reliable Web service composition method based on global QoS constraints decomposition and QoS dynamic prediction. The approach includes two critical phases: firstly, before service composition, global QoS constraints are decomposed into local constraints, and the problem of Web service dynamic composition is transformed to a local optimization problem; secondly, during the running time, optimal Web service is selected for the current abstract service based on predicted QoS values. Experiment results show that our approach can greatly enhance the reliability of composite Web service.

Research on Adaptation of Service-based Business Processes

This paper proposes an adaptation mechanism based on adaptation planning graph for service-based business processes. First, a three-layer representation model of service-based business process is introduced. Second, control-flow patterns of tasks, goal, logic model of service-based business process and adaptation planning graph are introduced to enforce reliability of composite web services at run-time. Finally, a simulation example of adaptation in service-based business processes is given. Simulations prove that this approach can efficiently guarantee the reliability of composite services at run-time. DOI : http://dx.doi.org/10.11591/telkomnika.v12i1.4148

Reliable Execution Based on CPN and Skyline Optimization for Web Service Composition

With development of SOA, the complex problem can be solved by combining available individual services and ordering them to best suit user's requirements. Web services composition is widely used in business environment. With the features of inherent autonomy and heterogeneity for component web services, it is difficult to predict the behavior of the overall composite service. Therefore, transactional properties and nonfunctional quality of service (QoS) properties are crucial for selecting the web services to take part in the composition. Transactional properties ensure reliability of composite Web service, and QoS properties can identify the best candidate web services from a set of functionally equivalent services. In this paper we define a Colored Petri Net (CPN) model which involves transactional properties of web services in the composition process. To ensure reliable and correct execution, unfolding processes of the CPN are followed. The execution of transactional composition Web service (TCWS) is formalized by CPN properties. To identify the best services of QoS properties from candidate service sets formed in the TCSW-CPN, we use skyline computation to retrieve dominant Web service. It can overcome that the reduction of individual scores to an overall similarity leads to significant information loss. We evaluate our approach experimentally using both real and synthetically generated datasets.

Exception Handling in Service-Based Business Processes by Applying Adaptation Planning Graph

This paper proposes an exception handling mechanism based on Adaptation Planning Graph for service-based business processes. A three-layer representation model of service-based business process is introduced firstly. And then, Logic Model of Service-based Business Process and Adaptation Planning Graph are introduced to enforce reliability of composite Web Services at run-time. Simulations prove that this approach can efficiently guarantee the reliability of composite services at run-time.

Composite web QoS with workflow conditional pathways using bounded sets

In our previous work (Dillon and Mansour 2009), a stochastic reliability model of atomic web services was proposed. Using the well-known classic two-state bounded set technique, we developed a service-oriented model that dynamically calculates the reliability of composite web services with rollback recovery (Mansour and Dillon in IEEE Trans Serv Comput 4(4), 2011). In order to improve the Quality of Service, fault tolerance techniques have been introduced using recovery block adaptation. Our workflow was based on series-parallel structures that constitute parts of existing structures. It is worth mentioning that major service-oriented systems contain larger and more complex structures than the simple series and parallel ones. This is a limitation in our previous approach. In order to consider more realistic service-oriented systems, other main structures, such as AND, XOR and Loop, should be included into our model. In this article, our previous structures are generalized to include AND, XOR and Loops. In addition to generalized structures, we extended the existing two-state bounded set technique to include three-state systems. This extension was especially motivated by XOR-based structures. A comparative study between bounded set techniques and a new stochastic model is also presented. Our simulation results accurately reflect the performance of the new proposed model and confirm our theoretical studies. Furthermore, Monte Carlos simulations were performed and the results obtained clearly validate our stochastic model.

Dependability and Rollback Recovery for Composite Web Services

In this paper, we propose a service-oriented reliability model that dynamically calculates the reliability of composite web services with rollback recovery based on the real-time reliabilities of the atomic web services of the composition. Our model is a hybrid reliability model based on both path-based and state-based models. Many reliability models assume that failure or error arrival times are exponentially distributed. This is inappropriate for web services as error arrival times are dependent on the operating state including workload of servers where the web service resides. In this manuscript, we modify our previous model (for software based on the Doubly Stochastic Model and Renewal Processes) to evaluate the reliability of atomic web services. In order to fix our idea, we developed the case of one simple web service which contains two states, i.e., idle and active states. In real-world applications, where web services could contain quite a large number of atomic services, the calculus as well as the computing complexity increases greatly. To limit our computing efforts and calculus, we chose the bounded set techniques that we apply using the previously developed stochastic model. As a first type of system combination, we proposed to study a scheme based on combining web services into parallel and serial configurations with centralized coordination. In this case, the broker has an acceptance testing mechanism that examines the results returned from a particular web service. If it was acceptable, then the computation continues to the next web service. Otherwise, it involves rollback and invokes another web service already specified by a checkpoint algorithm. Finally, the acceptance test is conducted using the broker. The broker can be considered as a single point of failure. To increase the reliability of the broker introduced in our systems and mask out errors at the broker level, we suggest a modified general scheme based on Triple modular redundancy and N-version programming. To imitate a real scenario where errors could happen at any stage of our application and improve the quality of Service QoS of the proposed model, we introduce fault-tolerance techniques using an adaption of the recovery block technique.

Research on Exception Handling of Composite Services Based on Compensation Business Process Graph

To enforce consistency and reliability of composite Web services at run-time, this paper proposes a novel approach based on compensation business process graph to addressing the problem of exception handling in composite services. According to compensation dependencies among tasks in business processes, the automatic generation of compensation business process graph is proposed. Compensation task, compensation goal and application model of service transfer are discussed in detail, and the relevant supporting infrastructure and technique are introduced. Based on this, algorithms for automatic generation of compensation dependency and compensation business process graph, as well as algorithm for exception handling during execution of composite services, are proposed. When exceptions are handled with forward- or backward-recovery methods during execution of composite services, the approach can guarantees compensation achieving, and also gives consideration to the problem that there are no compensation services or the cost to achieve compensation is too expensive. The mechanism described here improves self-adjustability and stability of composite services in the course of deployment and execution. Simulations prove that the approach can efficiently guarantee the consistency and reliability of composite services at run-time.