A study on resource provisioning of multi-tier web applications in cloud computing

Web applications these days are mostly multi-tier for the sake of software reusability and flexibility. However it is very difficult to estimate the behaviour of workloads in these tiers due to the fact that resource demand at each tier is distinct. So it becomes very confronting to allocate resources at each tier. In order to fulfil SLA (Service Level Agreement) requirements it becomes necessary to provision resources at each tier separately. Recently various approaches on control theory and dynamic approaches have been proposed for the provisioning of resources in cloud. In this paper we identify those challenges and conduct a review on those control theory and dynamic approaches for allocation of resources in multi-tier applications. On the basis of advantages and disadvantages we develop a blueprint for research directions to enhance the effectiveness of resource provisioning in multi-tier applications.