An approach to dynamic web service composition

Today, changeable requirements to modern web-oriented services demand their fast development and constant reengineering. This is realized via dynamic composition of services, allowing to estimate changes of both functional and nonfunctional service parameters. The last ones are considered using Web Services Agreement technique. Nevertheless, state-of-the-art SLA-aware methods are not able to consider all classes of non-functional parameters. They also don’t provide service run-time support and dynamic reconfiguration. The novel approach to dynamic Web Services Composition, extending SLA with QoS ontology, is described in the paper. It includes service selection agents that use the QoS ontology and WS-Agreements, allowing agents to choose the most appropriate service based on quality preferences exposed by service consumer. The proposed approach allows performing dynamic WS composition based on SLA, providing required values of QoS parameters, improving general QoS and decreasing service development and re-engineering time

ADVANCED APPROACH TO WEB SERVICE DISCOVERY AND SELECTION

Web Service Composition (WSC) is a process that helps to save much programming and cost effort by reusing existing components – web services. This process consists of two major stages – Web Service Discovery and Selection (WSD, WSS). This paper presents an overview of current state-of-the-art WSD and WSS methods. It also provides an analysis and highlighting of major problems like lack of support of the syntactical description in fuzzy logic algorithms in WSD and complex approach shortage in WSS problem. Moreover WSC approach and SLA-Aware WSC System are presented