Currently, a large number of smart objects and different types of devices are interconnected and communicate via Internet Protocol that creates a worldwide ubiquitous and pervasive network called the Internet of Things (IoT). With an increase in the deployment of smart objects, IoT is expected to have a significant impact on human life in the near future. A majorbreakthrough in bridging the gap between virtual and physical worlds came from the vision of the Web of Things (WoT), which employs open Web standards in achieving information sharing and objects interoperability. Social Web of Things (SWoT) further extends WoT to integrate smart objects with social networks and is observed to not only bridge between physical and virtual worlds but also facilitate continued interaction between physical devices and human. This makes SWoT the most promising approach and has now become an active research area.This survey introduces necessary background and fundamentals to understand current efforts in IoT, WoT and SWoT by reviewing key enabling technologies. These efforts are investigated in detail from several different perspectives such as architecture design, middleware, platform, systems implementation, and application in hand. Moreover, a large number of platforms and applications are analyzed and evaluated from various alternatives have become popular during the past decade. Finally, we address associated challenges and highlight potential research to be perused in future.

Choices for interaction with things on Internet and underlying issues

Cloud computing has gained significant attention of industry and academic sectors which are interested in adopting or experimenting with this technology. An increasing number of companies are expected to migrate their systems to cloud enabled infrastructures. However, there has not been much attention paid to provide sufficient process support. Since migration projects are likely to encounter several kinds of challenges, it is important to identify and share the process and logistical requirements of migration projects in order to build a body of knowledge of appropriate process, methods, and tools. This paper purports to contribute to the growing knowledge of how to migrate existing systems to cloud computing by reporting our effort aimed at migrating an Open Source Software (OSS) framework, Hackystat, to cloud computing. We report the main steps followed, the process and technical challenges faced, and some of the strategies that helped us to address those challenges. We expect the reported experiences can provide readers with useful insights into the process and technical aspects that should be considered when migrating existing software systems to cloud computing infrastructures.

Migrating Service-Oriented System to Cloud Computing: An Experience Report

In recent years, service-based applications are deemed to be one of the new solutions to build an enterprise application system. In order to answer the most demanding needs or adaptations to the needs of changed services quickly, service composition is currently used to exploit the multi-service capabilities in the Information Technology organizations. While web services, which have been independently developed, may not always be compatible with each other, the selection of optimal services and composition of these services are seen as a challenging issue. In this paper, we present cuckoo search algorithm for web service composition problem which is called ‘CSA-WSC’ that provides web service composition to improve the quality of service (QoS) in the distributed cloud environment. The experimental results indicate that the CSA-WSC compared to genetic search skyline network (GS-S-Net) and genetic particle swarm optimization algorithm (GAPSO-WSC) reduces the costs by 7% and responding time by 6%, as two major reasons for the reduction of improvement of the quality of service. It also increases provider availability up to 7.25% and the reliability to 5.5%, as the two important QoS criteria for improving the quality of service.

CSA-WSC: cuckoo search algorithm for web service composition in cloud environments

https://repositorio.grial.eu/bitstream/grial/1359/1/201808-PIM-PSM-ecosystems-postprint.pdf

Validation of the learning ecosystem metamodel using transformation rules

Today, cloud providers represent their individual services with several functional and non-functional properties in various environments. Discovering and selecting an appropriate atomic service from a pool of activated services are a main challenge in the multi-cloud service composition. Minimizing the number of cloud providers is a critical matter in the service composition problem, which effects on energy consumption, response time and total cost. This paper presents a hybrid formal verification approach to assess the service composition in multi-cloud environments though the decreasing number of cloud providers to gain final service composition with a high level of Quality of Service (QoS). The presented approach provides behavioral modeling to examine the procedure of user’ requests, service selection, and composition in a multi-cloud environment. Also, the proposed approach permits analysis of the service composition using a Multi-Labeled Transition Systems (MLTS)-based model checking and Pi-Calculus-based process algebra methods for monitoring the functional specifications and non-functional properties as the QoS standards. In addition, the proposed approach satisfies the functional properties for the multi-cloud service composition. The experimental results proved the feasibility of the proposed approach with performance evaluations and some confirmation setups.

A hybrid formal verification approach for QoS-aware multi-cloud service composition

Web services provide distributed communication in a platform independent way. The WS-* standards define how middleware aspects (security, reliability, transactions, etc.) can be realized through web services. Although the WS-Policy standard family can be used to configure the various WS-* protocols, they are very hard to construct and to maintain manually. In addition, most SOA products and Grid systems implementing these standards provide their own methods for configuring these protocols, making it very difficult to match the various configuration options of different products. This fact inspired us to propose a platform independent metamodel for describing distributed systems of web services including the most important WS-* standards. The present article defines the full metamodel, it specifies the corresponding programming language formally, and it shows the productivity of the framework built around the metamodel through real-life examples. The framework is capable of generating product specific configuration files and source codes, resulting in directly interoperable applications even between different SOA products. The framework could also promote interoperability with Grid systems built on WS-* protocols.

A Metamodel for the Web Services Standards

The basic building blocks of SOA systems are web services. WSDL, the standard language for defining web services, is far too complex and redundant to be efficiently handled by humans. Existing solutions use either graphical representations (UML, etc.), which are again inefficient in large scale projects, or define web services in the implementation’s native language, which is a bottom-up approach risking interface stability. Both lack support for concepts like conditions, access-rights, etc. The domain specific language introduced in this paper uses a Java and C#-like language for describing web service interfaces. It has the same descriptive power as WSDL while maintaining simplicity and readability. Examples show how to use the language, and how it can be compiled into WSDL.

A Human Readable Platform Independent Domain Specific Language for BPEL

The proposed architecture of the Hungarian e-Government Framework, mandating the functional co-operation of independent organizations, puts special emphasis on interoperability. WS-* standards have been created to reach uniformity and interoperability in the common middleware tasks for web services such as security, reliable messaging and transactions. These standards, however, while existing for some time, have implementations slightly different in quality. In order to assess implementations, thorough tests should be performed, and relevant test cases ought to be accepted. For selecting mature SOA products for e-Government application, a methodology of such an assessment is needed. We have defined a flexible and extensible test bed and a set of test cases for SOA products considering three aspects: compliance with standards, interoperability and development support.

/pdf/evaluation-of-ws-standards-based-interoperability-of-soa-4q1wgm9spn.pdf

Evaluation of WS-* Standards Based Interoperability of SOA Products for the Hungarian e-Government Infrastructure

/pdf/evaluation-of-ws-standards-based-interoperability-of-soa-19vp0mix68.pdf

Web services are built on XML. They use XML for describing the service interface, they use XML for message exchange and the WS- $^*$ protocols that provide addressing, security and reliable messaging also use XML. This burdens the communication with a large response time overhead compared to binary distributed communications like CORBA or RMI. Therefore, it is important to know how to design the interface of a web service so we can minimize the communication overhead. In this paper we propose a performance model with which the response time overhead of web services with arbitrary interfaces can be predicted if the coefficients of the model are calculated from some simple measurements for the given set of test cases. The paper shows the measurement results for two web service frameworks and also gives a detailed description of the performance model.

Balazs Simon

Papers

A Metamodel for the Web Services Standards

A Human Readable Platform Independent Domain Specific Language for BPEL

Evaluation of WS-* Standards Based Interoperability of SOA Products for the Hungarian e-Government Infrastructure

Evaluation of WS-* Standards Based Interoperability of SOA Products for the Hungarian e-Government Infrastructure

A Performance Model for the Web Service Protocol Stacks