Technical Report: A Trace-Based Performance Study of Autoscaling Workloads of Workflows in Datacenters

To improve customer experience, datacenter operators offer support for simplifying application and resource management. For example, running workloads of workflows on behalf of customers is desirable, but requires increasingly more sophisticated autoscaling policies, that is, policies that dynamically provision resources for the customer. Although selecting and tuning autoscaling policies is a challenging task for datacenter operators, so far relatively few studies investigate the performance of autoscaling for workloads of workflows. Complementing previous knowledge, in this work we propose the first comprehensive performance study in the field. Using trace-based simulation, we compare state-of-the-art autoscaling policies across multiple application domains, workload arrival patterns (e.g., burstiness), and system utilization levels. We further investigate the interplay between autoscaling and regular allocation policies, and the complexity cost of autoscaling. Our quantitative study focuses not only on traditional performance metrics and on state-of-the-art elasticity metrics, but also on time- and memory-related autoscaling-complexity metrics. Our main results give strong and quantitative evidence about previously unreported operational behavior, for example, that autoscaling policies perform differently across application domains and by how much they differ.Comment: Technical Report for the CCGrid 2018 submission "A Trace-Based Performance Study of Autoscaling Workloads of Workflows in Datacenters

A Taxonomy of Workflow Management Systems for Grid Computing

With the advent of Grid and application technologies, scientists and engineers are building more and more complex applications to manage and process large data sets, and execute scientific experiments on distributed resources. Such application scenarios require means for composing and executing complex workflows. Therefore, many efforts have been made towards the development of workflow management systems for Grid computing. In this paper, we propose a taxonomy that characterizes and classifies various approaches for building and executing workflows on Grids. We also survey several representative Grid workflow systems developed by various projects world-wide to demonstrate the comprehensiveness of the taxonomy. The taxonomy not only highlights the design and engineering similarities and differences of state-of-the-art in Grid workflow systems, but also identifies the areas that need further research.Comment: 29 pages, 15 figure

Continuing Professional Development and Workplace Learning

Reviews trends in the continuing professional development (CPD) of library and information staff in relation to contemporary university library practice in the digital world, highlighting the impact of technology on content and delivery. Discusses current drivers of CPD, multiple routes to professional development, technological impacts on work and learning, mentoring and reflection as professional meta-competencies, leadership institutes and organisational development programmes, and practitioner doctorates as advanced professional development. Concludes that CPD is particularly important because of continuing rapid technology-driven change and that education, research and development activities should be seen as a continuum informing, enhancing and advancing university library practice

Grass clover ley species, variety selection and management

Grass clover leys form the basis of most organic farming systems yet the selection of seed mixtures is often founded on tradition or cost. Based on a review of recent and past research this review provides a wealth of information on grass and legume species and varieties, mixture selection, ley establishment and pasture management. The objective of the Grass Clover Ley research review are: 1. To identify all the relevant research undertaken 2. Collate the results of the research 3. Draw on farm and commercial experience 4. Summarise the practical implications of the research for organic farming 5. Facilitate access to the results of research to advisers in a form which allows easy transfer to farmers. The report presents key conclusions about the choice of legume and gras species and varietes, the management of swards and their role for fertility building