Towards effective dynamic resource allocation for enterprise applications

The growing use of online services requires substantial supporting infrastructure. The efficient deployment of applications relies on the cost effectiveness of commercial hosting providers who deliver an agreed quality of service as governed by a service level agreement for a fee. The priorities of the commercial hosting provider are to maximise revenue, by delivering agreed service levels, and minimise costs, through high resource utilisation. In order to deliver high service levels and resource utilisation, it may be necessary to reorganise resources during periods of high demand. This reorganisation process may be manual or alternatively controlled by an autonomous process governed by a dynamic resource allocation algorithm. Dynamic resource allocation has been shown to improve service levels and utilisation and hence, profitability. In this thesis several facets of dynamic resource allocation are examined to asses its suitability for the modern data centre. Firstly, three theoretically derived policies are implemented as a middleware for a modern multi-tier Web application and their performance is examined under a range of workloads in a real world test bed. The scalability of state-of-the art resource allocation policies are explored in two dimensions, namely the number of applications and the quantity of servers under control of the resources allocation policy. The results demonstrate that