Service Oriented Computing Paradigm Research Articles

Evaluating the Reliability of PwCOV: A Loosely Coupled Software as a Service for COVID-19 Data Processing System

The pandemic coronavirus diseases 2019 are generating different data sets in different regions of the world. The data sets are observed to be available in geographically separated medical entities. However, the demand for accessing and reliable delivery of such datasets through a web-based module is increasing gradually. In this work, we propose a novel cycle of reliability evaluation model for deployment of Software as a Service-based prototype for the coronavirus disease data processing system. We call it as PwCOV. The prototype generates clinical remarks through the paradigm of service-oriented computing, cluster-based load balancing web servers, and loosely coupled software principles. The applicability of PwCOV for processing isolated disease datasets is discussed against different stress of set of user entities. The validity and applicability of the proposed model are evaluated through statistical analysis. The reliability of the PwCOV is observed by evaluating the recorded status of the business logic execution, failure count and failure rate. The study reveals that the PwCOV is affective for processing disease data set for a collaborative set of tenants. A novel methodology is designed for the deployment of software as a service for the COVID-19 data processing system using a load balancing cluster base web server, where the roles of service-oriented computing are segregated among different layers. The limitation of such deployment is also discussed for multi-tenant environment.

A Hybrid Approach for Improving the Design Quality of Web Service Interfaces

A key success of a Web service is to appropriately design its interface to make it easy to consume and understand. In the context of service-oriented computing (SOC), the service’s interface is the main source of interaction with the consumers to reuse the service functionality in real-world applications. The SOC paradigm provides a collection of principles and guidelines to properly design services to provide best practice of third-party reuse. However, recent studies showed that service designers tend to pay little care to the design of their service interfaces, which often lead to several side effects known as antipatterns . One of the most common Web service interface antipatterns is to expose a large number of semantically unrelated operations, implementing different abstractions, in one single interface. Such bad design practices may have a significant impact on the service reusability, understandability, as well as the development and run-time characteristics. To address this problem, in this article, we propose a hybrid approach to improve the design quality of Web service interfaces and fix antipatterns as a combination of both deterministic and heuristic-based approaches. The first step consists of a deterministic approach using a graph partitioning-based technique to split the operations of a large service interface into more cohesive interfaces, each one representing a distinct abstraction. Then, the produced interfaces will be checked using a heuristic-based approach based on the non-dominated sorting genetic algorithm (NSGA-II) to correct potential antipatterns while reducing the interface design deviation to avoid taking the service away from its original design. To evaluate our approach, we conduct an empirical study on a benchmark of 26 real-world Web services provided by Amazon and Yahoo. Our experiments consist of a quantitative evaluation based on design quality metrics, as well as a qualitative evaluation with developers to assess its usefulness in practice. The results show that our approach significantly outperforms existing approaches and provides more meaningful results from a developer’s perspective.

OGC-to-W3C Services: A Wrapper-Based Solution for Geospatial Metadata Exchange

When trying to compose services that are developed according to different standards, interoperability issues arise that are often faced by developing ad-hoc solutions. A typical example is represented by the composition of W3C and OGC services, which were developed more or less concurrently by independent organizations. In such a context, developing a wrapper that abstracts as much as possible the inner details and logic of a wrapped service well embraces the low-coupled nature of the general Service Oriented Computing paradigm. This paper focuses on the proper management of geospatial metadata into a W3C-based environment and is based on the development of a wrapper that exposes OGC functionality in a W3C-compliant way, thus overcoming the technical differences between the two types of services. To efficiently accomplish this task, a flexible, wrapper-based, and standard-compliant mechanism for metadata retrieval is proposed that avoids the use of third-party entities. The proposal exploits the scalable and adaptable nature of the WS-Metadata (Web Services Metadata) specification.

Improving the Safety and Security of Wide-Area Cyber–Physical Systems Through a Resource-Aware, Service-Oriented Development Methodology

This paper presents a service-oriented development methodology for wide-area cyber–physical systems (CPS) such as smart grid and vehicular networks. Unlike the traditional task-based development approach from the domains of automotive and avionics, the proposed service-oriented development methodology inherently enables disruption-free incremental system deployment and reconfiguration that are fundamental requirements for handling the “always-online” nature of emerging wide-area CPS application domains such as smart grid and vehicular networks. The proposed service-oriented CPS development methodology extends the traditional service-oriented computing (SOC) paradigm for handling hard real-time CPS aspects by introducing resource-aware service deployment and quality-of-service (QoS)-aware service operation phases. The proposed CPS development methodology also supports a streamlined formal interface between the traditional computer-aided feedback controller design environments and SOC paradigm. The paper utilizes a simulation-based smart grid case study to illustrate the advantages of the proposed methodology for developing wide-area cyber–physical systems with improved safety and security characteristics. The paper also identifies a set of technological requirements for the proposed service-oriented CPS development methodology that should guide future research in this area.

Assessing Web Services Interfaces with Lightweight Semantic Basis

In the last years, Web Services have become the technological choice to materialize the Service-Oriented Computing paradigm. However, a broad use of Web Services requires efficient approaches to allow service consumption from within applications. Currently, developers are compelled to search for suitable services mainly by manually exploring Web catalogs, which usually show poorly relevant information, than to provide the adequate glue-code for their assembly. This implies a large effort into discovering, selecting and adapting services. To overcome these challenges, this paper presents a novel Web Service Selection Method. We have defined an Interface Compatibility procedure to assess structural-semantic aspects from functional specifications - in the form of WSDL documents - of candidate Web Services. Two different semantic basis have been used to define and implement the approach: WordNet, a widely known lexical dictionary of the English language; and DISCO, a database which indexes co-occurrences of terms in very large text collections. We performed a set of experiments to evaluate the approach regarding the underlying semantic basis and against third-party approaches with a data-set of real-life Web Services. Promising results have been obtained in terms of well-known metrics of the Information Retrieval field.

Maintainability prediction of web service using support vector machine with various kernel methods

The present day software are mostly developed based on Service-Oriented Computing (SOC), which assembles loosely coupled pieces of software called services. With the increase in the number of development of these varieties of service oriented software, their effective maintenance plays an important role for the developers. The quality of SOC can be best assessed by the use of software metrics. In this paper, different object-oriented software metrics have been considered in order to design a model for predicting maintainability of SOC paradigm. Further support vector machine with different type of kernels have been considered for predicting maintainability of SOC paradigm. This paper also focuses on the effectiveness of feature selection techniques such as univariate logistic regression analysis, cross correlation analysis, rough set analysis, and principal component analysis. The results show that, maintainability of SOC paradigm can be predicted by application of various object-oriented metrics. The results further indicated that, it is possible to find a small subset of object-oriented metrics out of total available various object-oriented metrics, that enables prediction of maintainability with higher accuracy.

A Majority Vote Based Classifier Ensemble for Web Service Classification

Service oriented architecture is a glue that allows web applications to work in collaboration. It has become a driving force for the service-oriented computing (SOC) paradigm. In heterogeneous environments the SOC paradigm uses web services as the basic building block to support low costs as well as easy and rapid composition of distributed applications. A web service exposes its interfaces using the Web Service Description Language (WSDL). A central repository called universal description, discovery and integration (UDDI) is used by service providers to publish and register their web services. UDDI registries are used by web service consumers to locate the web services they require and metadata associated with them. Manually analyzing WSDL documents is the best approach, but also most expensive. Work has been done on employing various approaches to automate the classification of web services. However, previous research has focused on using a single technique for classification. This research paper focuses on the classification of web services using a majority vote based classifier ensemble technique. The ensemble model overcomes the limitations of conventional techniques by employing the ensemble of three heterogeneous classifiers: Naive Bayes, decision tree (J48), and Support Vector Machines. We applied tenfold cross-validation to test the efficiency of the model on a publicly available dataset consisting of 3738 real world web services categorized into 5 fields, which yielded an average accuracy of 92 %. The high accuracy is owed to two main factors, i.e., enhanced pre-processing with focused feature selection, and majority based ensemble classification.

A Stitch in Time Saves Nine: Early Improving Code-First Web Services Discoverability

Web Services represent a number of standard technologies and methodologies that allow developers to build applications under the Service-Oriented Computing paradigm. Within these, the WSDL language is used for representing Web Service interfaces, while code-first remains the de facto standard for building such interfaces. Previous studies with contract-first Web Services have shown that avoiding a specific catalog of bad WSDL specification practices, or anti-patterns, can reward Web Service publishers as service understandability and discoverability are considerably improved. In this paper, we study a number of simple and well-known code service refactorings that early reduce anti-pattern occurrences in WSDL documents. This relationship relies upon a statistical correlation between common OO metrics taken on a service's code and the anti-pattern occurrences in the generated WSDL document. We quantify the effects of the refactorings — which directly modify OO metric values and indirectly alter anti-pattern occurrences — on service discovery. All in all, we show that by applying the studied refactorings, anti-patterns are reduced and Web Service discovery is significantly improved. For the experiments, a dataset of real-world Web Services and an academic service registry have been employed.

Multi-robot data mapping simulation by using microsoft robotics developer studio

This document summarizes the goals achieved in the development of a data mapping application, for a multi-robot system, implemented as a service with the guidelines found in the Service Oriented Computing paradigm (SOC). The obtained service generates both local and global maps in the reconstruction of a virtual scenario: the local maps represent the surrounding area around each one of the mobile robots, and the global one the totality of the scenario where the robots move. The information of the global map is continuously updated by merging the data coming from the local maps by using a novel approach: each one of the maps manages a confidence level value that defines which of the data coming from the maps is worthy of being updated into the global one. This technique is not present in related work. The Microsoft Robotics Developer Studio framework was chosen for its implementation because of the advantages that this tool offers in the management of concurrent and distributed processes, typically found in both a robotics platform and in a multi-robot system.

Modeling and verifying choreographed multi-agent-based web service compositions regulated by commitment protocols

The competency to compose web services from available services is one of the most crucial problems in the paradigm of service-oriented computing. Conventional software engineering approaches and even standard languages compose web services as workflow models that control the business logic required to coordinate data over participating services. Such models would not apply to the design of multi-agent based web services, which offer high-level abstractions that support autonomy, business-level compliance, and flexible dynamic changes. In this article, we model interactions among multi-agent based web services by commitment modalities in the form of contractual obligations and devote multi-agent commitment protocols to regulate such interactions and engineer services composition. We develop and fully implement an automatic verifier by enriching the MCMAS model checker with certain symbolic algorithms to verify the correctness of protocols, given properties expressed in a temporal commitment logic, suitably extended with actions. We analyze the time and space complexity of the verifier. Finally, we present the experimental results of two case studies, adopted to check the verifier’s efficiency and scalability.

An experimental service composition tool for media-centric networked applications

In order to explore diverse types of media-centric service composition in real environments, we have built a service-oriented testbed named as FIRST@PC (Future Internet Research on Sustainable Testbed based on PC). FIRST@PC targets a flexible and cost-effective testing environment where media-centric service compositions are flexibly realized on top of computing/networking resources. In this paper we design and implement an OMX (Open Media eXperiment for service composition) experiment control tool to support media-centric service composition. By following the SOC (service-oriented computing) paradigm, the OMX tool assists experimenters to flexibly integrate computing and networking services. To explore the possibility of media-centric service composition, we also prototype the FIRST@PC testbed consisting of multimedia computing and networking devices. The implemented OMX tool is verified by an HD media service composition scenario run on this prototyped testbed.

BeC 3: Behaviour Crowd Centric Composition for IoT applications

Service Oriented Computing (SOC) is a common way to build applications/services by composing distributed bricks of logic. Recently, the SOC paradigm has been considered for the design and implementation of Internet of Things (IoT) applications by abstracting objects as service providers or consumers. Based on this trend, we proposed in a previous work D-LITe: a lightweight RESTful virtual machine that allows ubiquitous logic description and deployment for IoT applications using Finite State Transducers (FST). Though D-LITe allows faster and more efficient application creation for heterogeneous objects, it turns out that FST design can be fastidious for inexperienced users. With that in mind, we propose in this paper BeC3 (Behaviour Crowd Centric Composition) an innovative crowd centric architecture, grounded on D-LITe. It provides a simpler way to compose interactions between IoT components. The idea is to reverse the bottom-up approach of SOC by a rather top-down vision in which the user expresses the expected result of his application by composing behaviours that are proposed by contributors. These behaviours are deployed on each concerned component, which then act exactly as needed to fulfil their role in the composition. The crowd-Centric aspect of this platform allows a community-based design, granting a wide panel of modular and incremental interactions for a wide variety of components. Eventually, BeC3 will give inexperienced users the ability to organise, interconnect and compose both state of the art web-services and IoT components to create interactive 2.0-like applications for the IoT.

Non-Intrusive Elastic Query Processing in the Cloud

Cloud computing is a very promising paradigm of service-oriented computing. One major benefit of cloud computing is its elasticity, i.e., the system’s capacity to provide and remove resources automatically at runtime. For that, it is essential to design and implement an efficient and effective technique that takes full advantage of the system’s potential flexibility. This paper presents a non-intrusive approach that monitors the performance of relational database management systems in a cloud infrastructure, and automatically makes decisions to maximize the efficiency of the provider’s environment while still satisfying agreed upon "service level agreements" (SLAs). Our experiments conducted on Amazon’s cloud infrastructure, confirm that our technique is capable of automatically and dynamically adjusting the system’s allocated resources observing the SLA.

Application of Services Relation Tracing to Automated Web Service Composition

Web service composition has received much interest due to its potential to achieve the visionary promise of Service-Oriented Computing paradigm in which services can be utilized as the basic constructs to create flexible dynamic business processes and agile applications that may span organizations and computing platforms with little effort even automatically. In this paper, we proposed a snowball method for automated Web service composition which is based on service relation tracing which starts off rather like a standard ego-centered network study. It discoveries one or several available Web services which can accept the input parameters in user requirement through sematic reasoning and determines whether its output parameters meet the user requirements. And then it fetches other candidate services following the Sequential-total and Sequential-partial relations, investigates their outputs, also asks further sequential relations, and so forth through a succession of waves of spreading. So the process is repeated and the composite service is constructed incrementally tracing sequential relations in Service Network just like a snowball. The experiment shows that the approach proposed in this paper can greatly improve the accuracy and efficiency of Web service composition.

Data Management in the Cloud: Challenges and Opportunities

Cloud computing has emerged as a successful paradigm of service-oriented computing and has revolutionized the way computing infrastructure is used. This success has seen a proliferation in the number of applications that are being deployed in various cloud platforms. There has also been an increase in the scale of the data generated as well as consumed by such applications. Scalable database management systems form a critical part of the cloud infrastructure. The attempt to address the challenges posed by the management of big data has led to a plethora of systems.

A Multi-Staged Blackboard Query Optimization Framework for World-Spanning Distributed Database Resources

With the advent of distributed computing, particularly since the emergence of Grids, Clouds and other Service Oriented Computing paradigms, the querying of huge datasets of distributed databases or data repositories on a global scale has become a challenging research question. Currently, beside various other topics, two major concerns in this research area have to be addressed: data access & integration and query execution planning. Our research effort addresses the second issue, namely the query optimization of distributed database queries. Hereby we consider a variety of different heterogeneous and homogeneous infrastructures, parallel algorithms, and huge datasets, which span across several virtual organizations (VOs) with usually no centralized authority. This paper introduces a novel heuristic framework for the optimization of query execution plans (QEP) on a world-wide scale. Our work is based on a multi-staged blackboard mechanism to determine which available data, resources and operations have to be considered to perform a query optimally. Moreover, an evaluation scenario proves our findings that even small changes in the selection of e.g. sort operations for a query execution tree (QET) lead to significant performance improvements.

Improving Web Service descriptions for effective service discovery

Service-Oriented Computing (SOC) is a new paradigm that replaces the traditional way to develop distributed software with a combination of discovery, engagement and reuse of third-party services. Web Service technologies are currently the most adopted alternative for implementing the SOC paradigm. However, Web Service discovery presents many challenges that, in the end, hinder service reuse. This paper reports frequent practices present in a body of public services that attempt to prevent the discovery of any service. In addition, we have studied how to solve the discoverability problems that these bad practices cause. Accordingly, this paper presents a novel catalog of eight Web Service discoverability anti-patterns. We conducted a comparative analysis of the retrieval effectiveness of three discovery systems by using the original body of Web Services versus their corrected version. This experiment shows that the removal of the identified anti-patterns eases the discovery process by allowing the employed discovery systems to rank more relevant services before non-relevant ones, with the same queries. Moreover, we conducted a survey to collect the opinions from 26 individuals about whether the improved descriptions are more intelligible than the original ones. This experiment provides more evidence of the importance of correcting the observed problems.

Combining query-by-example and query expansion for simplifying web service discovery

The vision of a worldwide computing network of services that Service Oriented Computing paradigm and its most popular materialization, namely Web Service technologies, promote is a victim of its own success. As the number of publicly available services grows, discovering proper services is similar to finding a needle in a haystack. Different approaches aim at making discovery more accurate and even automatic. However they impose heavy modifications over current Web Service infrastructures and require developers to invest much effort into publishing and describing their services and needs. So far, the acceptance of this paradigm is mainly limited by the high costs associated with connecting service providers and consumers. This paper presents WSQBE+, an approach to make Web Service publication and discovery easier. WSQBE+ combines open standards and popular best practices for using external Web services with text-mining and machine learning techniques. We describe our approach and empirically evaluate it in terms of retrieval effectiveness and processing time, by using a data-set of 391 public services.

Service Oriented Computing in Practice – An Agenda for Research into the Factors Influencing the Organizational Adoption of Service Oriented Architectures

The paradigm of service-oriented computing (SOC) has emerged as an approach to provide flexibility and agility, not just in systems development but also in business process management. This modular approach to defining business flows as technology independent services has gained unanimous popularity among end-users and technology vendors alike. Although there is a significant amount of ongoing research on the potential of service oriented architectures (SOAs), there is a paucity of research literature on the factors affecting the adoption of service-oriented computing in practice. This paper reviews the current state of the technology, identifies the factors influencing the decision to adopt service-oriented computing as an enterprise strategy and discusses the associated research literature, and concludes with a suggested research agenda and conceptual framework for investigating the use of service-oriented computing in practice.

Interoperability Among Heterogeneous Services

Service-oriented computing (SOC) has been marked as the technology trend that caters for interoperability among the components of a distributed system. However, the emergence of various incompatible instantiations of the SOC paradigm, e.g. Web or peer-to-peer services (P2P), and the divergences encountered within each of these instantiations state clearly that interoperability is still an open issue, mainly due to its multi-dimensional nature. In this paper we address the interoperability problem by first presenting its multiple dimensions and then by describing a conceptual model called generic service model (GeSMO), which can be used as a basis for the development of languages, tools and mechanisms that support interoperability. We then illustrate how GeSMO has been utilized for the provision of a P2P service description language and a P2P invocation mechanism which leverages interoperability between heterogeneous P2P services and between P2P services and Web services.