Intelligent Load Balancing in Cloud Computer Systems

Cloud computing is an established technology allowing users to share resources on a large scale, never before seen in IT history. A cloud system connects multiple individual servers in order to process related tasks in several environments at the same time. Clouds are typically more cost-effective than single computers of comparable computing performance. The sheer physical size of the system itself means that thousands of machines may be involved. The focus of this research was to design a strategy to dynamically allocate tasks without overloading Cloud nodes which would result in system stability being maintained at minimum cost. This research has added the following new contributions to the state of knowledge: (i) a novel taxonomy and categorisation of three classes of schedulers, namely OS-level, Cluster and Big Data, which highlight their unique evolution and underline their different objectives; (ii) an abstract model of cloud resources utilisation is specified, including multiple types of resources and consideration of task migration costs; (iii) a virtual machine live migration was experimented with in order to create a formula which estimates the network traffic generated by this process; (iv) a high-fidelity Cloud workload simulator, based on a month-long workload traces from Google's computing cells, was created; (v) two possible approaches to resource management were proposed and examined in the practical part of the manuscript: the centralised metaheuristic load balancer and the decentralised agent-based system. The project involved extensive experiments run on the University of Westminster HPC cluster, and the promising results are presented together with detailed discussions and a conclusion

Seasons in hell: Charles S. Johnson and the 1930 Liberian Labor Crisis

In 1930, African American sociologist Charles S. Johnson of Fisk University traveled to the Republic of Liberia as the American member of a League of Nations commission to investigate allegations of slavery and forced labor in that West African nation. In the previous five years, the face of Liberia had changed after the large-scale development of rubber plantations on land leased by the Firestone Tire and Rubber Company, with headquarters in Akron, Ohio. Political turmoil greeted Johnson in Liberia, an underdeveloped nation teetering on the brink of economic collapse. This dissertation focuses on Johnson’s role as the key member of the League of Nations Commission of Inquiry, and examines events leading up to the investigation. Also touched upon are the life and career of Harvey S. Firestone, the history of the rubber and automobile industries, and Liberia’s relationship with the U. S. Department of State. Central to this dissertation, however, is Charles Johnson, an important and underappreciated figure in African American history. Johnson’s diplomatic approach to race relations in the United States earned him respect from philanthropic foundations that funded his research projects, but also led to criticism and jealousy from his black colleagues and peers. Because Johnson guarded his privacy so closely and left behind little in the way of personal information, the journal that he kept for six months in Liberia becomes all the more important as a clue to his inner thoughts and feelings, as well as a guide to his personality and character. Furthermore, Liberia shaped Johnson’s thinking as a scholar in important ways, particularly in regard to the economic foundations of exploitation, caste and class, and political disfranchisement. Johnson’s mission to Liberia and his spirited defense of that nation’s tribal citizens, as this study shows, suggests a more complicated and assertive individual that contrasts with the largely one dimensional image of him that has metastasized over the years. Indeed, Johnson was one of the few African Americans who showed any interest in the welfare of Liberia’s indigenous tribes. In that regard, he was a maverick, overlooked and underestimated

Sharing understandings of information systems development methodologies : a critical reflexive issue for practice and curriculum

Most contemporary organizations make use of computer-based information systems to support their management activities. There is considerable evidence that many of these systems experience problems during the development phases and a large proportion of these systems may, using specific criteria, be classed as failures. The reported high level of such failure in the development of computer-based information systems is not a new phenomenon for business, having been present almost from the inception of these systems. The frameworks that guide developers through the process can be labelled as information systems development methodologies, or ISDMs.For an educator involved with the teaching of some or all aspects of the development process this perceived high level of failure of systems development and implementation in practice raises some significant concerns. If there is a 'silver bullet' approach that students need to be equipped with to become successful systems developers we need to identify it and ensure that they are proficient with it. If there is no silver bullet we need to acknowledge this in our teaching and equip the students with the critical thinking skills to help them appreciate this in their later practice.This thesis takes as its central theme the view that there is currently no 'silver bullet' and one may never be found to fit all development projects and environments. Under such a constraint our students, as would-be practitioners, need to be helped to approach practice unfettered by a naïve belief that there is a single approach that offers guaranteed success in the development of information systems. Flexible, contingent and possibly creative approaches need to be fostered so that students can both work in the field and can contribute to both the overall understanding of that field and to their own personal development. The thesis considers the role of multiple perspectives, constructivism, language, communication and reflection as vehicles to allow the building and sharing of accessible understanding of information systems development methodologies in a tertiary education setting. The issues are explored through the design and development of a Masters course titled 'Information Systems Development Methodologies' that was designed and implemented at the University of South Australia in the period 1999 to 2008. The course was initially designed within an interpretivist paradigm and rather than following a traditional systems analysis and design path could be viewed more as a liberal arts course. However, as the course moved towards the end of its life it began to take on a more positivistic flavour.The story of the course emerged from a series of action learning cycles and is told from the perspective of the author who was both the researcher and the subject of the research.EThOS - Electronic Theses Online ServiceGBUnited Kingdo