A QoS framework for modeling and simulation of distributed services within a cloud environment

Distributed computing paradigm such as Cloud and SOA provides the architecture and medium for service computing which gives flexibility to organisations in implementing IT solutions meeting specific business objectives. The advancement of internet technology opens up the use of service computing and broaden the scope into areas classified as utility computing, computing solutions modelled as services allowing consumers to use and pay for solutions that includes applications and physical devices. The model of service computing offers great opportunity in cutting cost and deployment but also presents a case for user demands changes that is different from the usual service level agreement in computing deployment. Service providers must consider different aspects of consumer demands in provisioning of services including non-functional requirements such as Quality of Service, this not only relates to the users expectations but also managing the effective distribution of resources and applications. The normal model for meeting user requirements is over-stretched and therefore requires more information gathering and analysis of requirements that can be used to determine effective management in service computing by leveraging SOA and Cloud computing based on QoS factors. A model is needed to consider multiple criteria in decision making to enable proper mapping of resources from service composition level to resource provision for processing user request, a framework that is capable of analysing service composition and resource requirements. Thus, the aim of the thesis is to develop a framework for enabling service allocation in Cloud Computing based on SOA and QoS for analysing user requirements to ensure effective allocation and performance in a distributed system. The framework is designed to handle the top layer of user requirements in terms of application development and the lower layer of resource management, analysing the requirement in terms of QoS in order to identify the common factors that matches the user requirement and the available resources. The framework is evaluated using Cloudsim simulator to test its effectiveness in improving service and resource allocation in Distributed Computing environment. This approach offers a greater flexible to overcome issues of over-provisioning and underprovisioning of resources by maintaining an effective provisioning using Service Oriented QoS Enabled Framework (SOQ-Framework) for requirement analysis of service composition and resource capabilities.