Paweł Stelmach

Service Composition in Knowledge-based SOA Systems

In this paper, we present the solution of the problem of Service Composition in Knowledge-based SOA (Service Oriented Architecture) Systems. SOA based systems are built of services - atomic or complex ones. Each service may have a different functional and non-functional description. The methods how to retrieve atomic service and compose complex services according to the user’s needs are discussed here.

A Model for Automated Service Composition System in SOA Environment

In this paper a holistic approach to automated service composition in Service Oriented Architecture is presented. The model described allows to specify both functional and non-functional requirements for the complex service. In order to do so a decomposition of the complex service composition process into three stages is proposed, in which a structure, a scenario and an execution plan of a complex service is built. It is believed that service composition tool based on the proposed model will be able to create complex services satisfying efficiently both functional and nonfunctional requirements.

Planning-Based Method for Communication Protocol Negotiation in a Composition of Data Stream Processing Services

Data streaming is often used for video and sensor data delivery, nowadays gaining in popularity along with the development of mobile devices. In this paper we briefly describe a platform for automated composition of distributed data stream processing services. It decreases the complexity of composite service building process from the users point of view by introducing automation mainly in appropriate service selection and their communication protocols negotiation. This paper is focused on automated negotiation of communication protocols, which will be further used to transfer data among services. Data stream processing services are designed independently, often with many possible communication methods and not pointing directly to other services. With the use of the platform, they can be loosely coupled, forming a composite service od-demand. We present several approaches to communication protocol negotiation in a composition of data stream processing services and introduce planning-based approach. Finally, we discuss consequences of various approaches on an example composite service from image processing domain.

Service Composition Scenarios in the Internet of Things Paradigm

In this work the topic of service composition scenarios is introduced and discussed with the use of leading example of service composition in the transport domain. The example is used to visualize the connection to the Internet of Things paradigm. The service composition itself is defined with a holistic approach, describing all steps of the proposed composition process like: requirements definition, requirements decomposition or aggregation using domain ontology, composite service structure construction, service discovery, structure and service plan optimization. Lastly, implementation of service composition with service composition scenarios is discussed.

Web Service Composition with Uncertain Non-functional Parameters

The problem of service composition is of key importance in the Internet of Things paradigm. A composite Web Service can clearly determine how real life objects described as Web Services could interact with each other. This article proposes a non-functional parameters aggregation algorithm, used in composite service plan optimisation stage, taking into account the uncertainty of the nonfunctional parameters. Also, an optimisation algorithm, using the proposed aggregation method, is presented to show the complete solution for the problem. In this proposition, the algorithm focuses on composite service plan optimisation with uncertain parameters with the given uncertainty description on example of uncertainty parameter. However, the proposed algorithm can be generalized, so it can be used also with other uncertain parameters

Link prediction in dynamic networks of services emerging during deployment and execution of web services

We propose an approach, according to which the Web services interoperability and resulting composition schemes may be used to create the network structures reflecting the patterns according to which the services interact during execution of composition and execution queries. We show how to create so-called networks of Web services which allow to effectively use the network structural analysis and optimization techniques to solve the network composition problems. The service network is created on the basis of the semantic bindings between the services in the repository joined with the actual patterns of the service usage resulting from composition queries. Next we show how available techniques of dynamic network structure prediction and analysis may help to assess the future service usage and resource consumption of the service execution layer. Our approach is illustrated by the real data gathered from the PlaTel platform, dedicated to the complex service planning, management, provision, composition, execution and validation.

Trust-based security-level evaluation method for dynamic service-oriented environments

A method of decision‐making in security‐level estimation process of service‐based applications in future Internet architecture is proposed. We demonstrate how distributed services can be composed to form an application run within the next‐generation network infrastructure and their security level may be assessed. Our approach is illustrated by the experiments carried on exemplary application (virtual laboratory online lab, using future Internet IPv6 QoS architecture), in which our method was evaluated against two types of attacks observed with the use of traffic anomaly detection methods. Copyright

Universal Platform for Composite Data Stream Processing Services Management

Constant delivery of data and information through streaming methods is growing in popularity. Streaming is widely used for video and sensor data delivery, usually directly to the client. In this work we propose architecture of the platform for composition of several distributed streaming intermediaries, able to process the data stream on-line. Features of the platform consist of ability to create a composite stream on demand as well as update, delete or read its current state. Works on the platform are an on-going research effort and current work, presented in this work, focuses on separation of platform functionality into distributed software components for performance optimization. This distribution allows for optimizing each component’s behaviour regarding its usage characteristics. As an effect the platform’s streaming service management functionality is offered as a stateless service.

Communication Protocol Negotiation in a Composite Data Stream Processing Service

Data streaming services gain popularity but still only few works are focused on their composition and its detailed management, like communication protocol negotiation. In this paper, we describe a continued work on a platform for automated composition of distributed data stream processing services. With the platform a process of composite service building is simplified and negotiation among services automated. In the following sections we will present an overview of the platform, describe implemented negotiation approaches and their phases, and finally compare them in an experimental study.

A Web Service-Based Platform for Distributed Web Applications Integration

Web applications built according to the MVC pattern are growing in popularity. At the same time web services: either SOAP or REST-based are also gaining momentum, but their adoption in web applications is usually limited to a smaller scope and with little management of their behaviour and state. The approach presented in this work does not enforce cloud-based solutions; however, it is highly advised to refer to web services as not only web interfaces to other monolithic web applications but try to perceive them as preferably independent, stateless software components, easily scalable and deployable in the cloud. This potentially could lead to dramatic reduction of the cost of software services with simultaneous increase of performance on-demand. The presented platform confronts the discrepancies between MVC pattern and service adoption in web applications, and is a proposition that increases performance of both service-based applications as well as their design methods. It introduces mechanisms for increasing the scope of service integration and also web application integration, at the same time making it manageable through specialized tools.