Yang Syu

A Survey on Automated Service Composition Methods and Related Techniques

As a promising, low-cost, and agile way to develop software, in recent years automatic service composition has been a popular research topic receiving a lot of attentions. For this topic, upon our long-term study and paper reviewed, we present technical survey and observation in this paper, including indispensable background and preliminary knowledge. The survey assumes under traditional composition context. Moreover, following the survey and observation, we suggest two approach patterns and point out possible future challenge as well as direction, especially to the influence of the mature of mobile devices and environment.

Towards a Genetic Algorithm Approach to Automating Workflow Composition for Web Services with Transactional and QoS-Awareness

Service-oriented architecture implemented by Web Services is one of the most popular and promising software development paradigm that has brought some challenging research issues today. One of the most important issues is how to automate web service composition at design phase. Currently, there are many researchers concentrating on service composition problem that can be partitioned into three parts, dynamic workflow composition, QoS-aware, and transaction-aware service selection. This paper addresses the issue of automatic composing Web Services into an executable workflow not only according to user¡¦s functional requirements but also to their transactional properties and QoS characteristics. We propose an automatic composition approach through genetic algorithm to satisfy user¡¦s functional requirements, QoS criteria, and transactional requirements automatically at the same time. Experimental results are presented.

Genetic algorithm for QoS-aware dynamic web services composition

Nowadays, the Service-Oriented Architecture (SOA) as well as orchestration technology becomes trend of software development. The benefit of SOA is that we will save cost and time extremely due to the services utilized are already exist and reuse those services as well as integrate them. Currently, the main issues of SOA are how to define workflow as well as how to select the suitable services to perform this workflow with QoS. Many approaches separate workflow defined and services with QoS selected, therefore, will sacrifice the users feasibility. In this paper, we provide an approach to deal with the dynamic service composition issue based on the genetic algorithm and cases-based reasoning. This approach can support the flexible service workflow according to the users requirements and compose the workable services to complete this workflow.

Semantic-based automatic service composition with functional and non-functional requirements in design time

ContextIn recent years, the composition of ready-made and loosely coupled services into desired systems is a common industrial approach and a widely followed research topic in academia. In the field, the current research trend is to automate this composition; however, each of the existing efforts automates only a component of the entire problem. Therefore, a real automation process that addresses all composition concerns is lacking. ObjectiveThe objective is to first identify the present composition concerns and subsequently to devise a compositional approach that covers all concerns. Ultimately, we conduct a number of experiments to investigate the proposed approach. MethodWe identify the current composition concerns by surveying and briefly describing the existing approaches. To include all of the identified concerns, the solution space that must be searched is highly dimensioned. Thus, we adopt a genetic algorithm (GA) due to its ability to solve problems with such characteristics. Proposed GA-based approach is designed with four unusual independent fitness functions. Additionally, experiments are carried out and discussions are presented for verification of the design, including the necessity for and correctness of the independence and priority of the four fitness functions. ResultsThe case studies demonstrate that our approach can automatically generate the required composite services and considers all identified concerns simultaneously. The results confirm the need for the independence of the fitness function and also identify a more efficient priority for these functions. ConclusionsIn this study, we present an all-inclusive automatic composer that does not require human intervention and effort during the composition process and is designed for users who must address multiple composition concerns simultaneously, including requirements for overall functionality, internally workable dataflow, and non-functional transaction and quality-of-service considerations. Such multiple and complex composition requirements cannot be satisfied by any of the previous single-concern composition approaches.

Search based approach to forecasting QoS attributes of web services using genetic programming

ContextCurrently, many service operations performed in service-oriented software engineering (SOSE) such as service composition and discovery depend heavily on Quality of Service (QoS). Due to factors such as varying loads, the real value of some dynamic QoS attributes (e.g., response time and availability) changes over time. However, most of the existing QoS-based studies and approaches do not consider such changes; instead, they are assumed to rely on the unrealistic and static QoS information provided by service providers, which may seriously impair their outcomes. ObjectiveTo predict dynamic QoS values, the objective is to devise an approach that can generate a predictor to perform QoS forecasting based on past QoS observations. MethodWe use genetic programming (GP), which is a type of evolutionary computing used in search-based software engineering (SBSE), to forecast the QoS attributes of web services. In our proposed approach, GP is used to search and evolve expression-based, one-step-ahead QoS predictors. To evaluate the performance (accuracy) of our GP-based approach, we also implement most current time series forecasting methods; a comparison between our approach and these other methods is discussed in the context of real-world QoS data. ResultsCompared with common time series forecasting methods, our approach is found to be the most suitable and stable solution for the defined QoS forecasting problem. In addition to the numerical results of the experiments, we also analyze and provide detailed descriptions of the advantages and benefits of using GP to perform QoS forecasting. Additionally, possible validity threats using the GP approach and its validity for SBSE are discussed and evaluated. ConclusionsThis paper thoroughly and completely demonstrates that under a realistic situation (with real-world QoS data), the proposed GP-based QoS forecasting approach provides effective, efficient, and accurate forecasting and can be considered as an instance of SBSE.

A Review of the Automatic Web Service Composition Surveys

In recent years, developing needed software applications via the technique Web Service Composition (WSC) has been more and more popular. Moreover, benefit from the Semantic Web Services (SWSs) technology, it is possible to even automatically conduct WSC, i.e. the Automated Web Service composition (AWSC). Currently the AWSC is a well-studied research subject and which means the existence of a large number of related research efforts. To existing AWSC researches, our goal is to make complete and referable surveys of them, and in this paper we adopt a strategy which may be more efficient than directly reviewing original research papers that we inspect and focus on the already-published AWSC surveys, trying to take advantages of them. With an AWSC survey framework proposed by us previously, we present a modest review on the selected AWSC surveys which inspected the AWSC researches that largely benefit from the SWSs technology. For each selected AWSC survey, in this review we indicate what AWSC research concerns defined by us in the survey framework are covered by it and precisely describe its contents. With this review, the reader can easily and quickly find out proper AWSC surveys for more advanced information and reading.

A Survey to Service Composition Methods Using Aspects Classification

As a promising, few-risk, low-cost, and agile way to rapidly produce and construct executable intended software, in recent years automatic service composition related techniques and methods have been a prevailing and deeply-studied research field, receiving a lot of attentions. For this research field, upon our long-term studies and efforts as well as papers reviewed we present, in this article, a technical profound survey along with the future challenges and directions observed. Before the main body of the survey appears, there are introductions to some vital background knowledge and adopted survey framework, respectively. The framework used in organizing the structure of the survey has been aided and inspired by aspect-oriented paradigm.

A Genetic Algorithm with Prioritized Objective Functions for Service Composition

Since genetic algorithm was invented, it has been applied to solve lots of difficulties. One kind of the frequently encountered issues by it is problems having plural and conflicting objectives to be achieved simultaneously (i.e. multiobjective problems). However, it is unlikely to find an answer which is optimal or perfect to all conflicting objectives. The feasible way is searching compromises between these objectives and these compromises are called Pareto-optimal answers. There already are many techniques that can be used to find Pareto-optimal answers for multiobjective problems through genetic algorithm. The goal of us is addressing comprehensive service composition and it totally has four independent, conflicting, and prioritized objectives. The problem cannot be tackled by traditional way because the relationship between these objectives. To deal with such a special problem by genetic algorithm, we proposed a genetic algorithm design having layered and prioritized relationship between objective functions. Employing this design to overcome comprehensive service composition and, ultimately, we hope that the layered and prioritized functions design can be applied to other similar problems.

Transactional Web Services Composition: A Genetic Algorithm Approach

Service Oriented Architecture implemented by Web Services is one of the most popular and promising software development paradigm, however, it still has some challenging issues. One of that is how to automate web services composition at design time. Services composition reuses existing component services to provide composite service with more complexes, value-added functions that cannot be provided through any single component service; therefore it avoids constructing any new service from scratch. In this paper we propose an approach based on genetic algorithm to automatically composing web service without a workflow template beforehand and ensuring resulting service has reliable behavior (transactional properties). A composite service which is produced through our approach will be able to treat as a unit of work avoiding inconsistence and it does not ask user to define the workflow template manually. Experimental results are presented.

An Overview and Classification of Service Description Approaches in Automated Service Composition Research

In recent years, automated service composition has been a fervid research area in service computing. Within this area, service description plays a crucial role in terms of the development of a diverse number of automation schemes. In this paper, we provide an investigation and classification of the service description approaches that have been used in a diverse collection of automated service composition studies. To position the service description approaches used in automated service composition throughout the service description world and to clearly classify them, we propose five two-value dimensions. Using the proposed dimensions, we first perform a categorization and provide a simple introduction to current representative industrial service description standards. Subsequently, because we discovered that most of the studied automated composition approaches follow a tuple-based service description paradigm, an exhaustive classification and discussion of this paradigm is made, with the automated composition approaches adopting this paradigm as an example. Finally, we discuss issues that are currently relevant to the service description field and possible solutions. With this study, the reader can obtain a complete understanding of service description approaches used in automated service composition research, including their common formulation and assumptions.