63,944 research outputs found

    Self-organising agent communities for autonomic resource management

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    The autonomic computing paradigm addresses the operational challenges presented by increasingly complex software systems by proposing that they be composed of many autonomous components, each responsible for the run-time reconfiguration of its own dedicated hardware and software components. Consequently, regulation of the whole software system becomes an emergent property of local adaptation and learning carried out by these autonomous system elements. Designing appropriate local adaptation policies for the components of such systems remains a major challenge. This is particularly true where the system’s scale and dynamism compromise the efficiency of a central executive and/or prevent components from pooling information to achieve a shared, accurate evidence base for their negotiations and decisions.In this paper, we investigate how a self-regulatory system response may arise spontaneously from local interactions between autonomic system elements tasked with adaptively consuming/providing computational resources or services when the demand for such resources is continually changing. We demonstrate that system performance is not maximised when all system components are able to freely share information with one another. Rather, maximum efficiency is achieved when individual components have only limited knowledge of their peers. Under these conditions, the system self-organises into appropriate community structures. By maintaining information flow at the level of communities, the system is able to remain stable enough to efficiently satisfy service demand in resource-limited environments, and thus minimise any unnecessary reconfiguration whilst remaining sufficiently adaptive to be able to reconfigure when service demand changes

    Optimizing egalitarian performance in the side-effects model of colocation for data center resource management

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    In data centers, up to dozens of tasks are colocated on a single physical machine. Machines are used more efficiently, but tasks' performance deteriorates, as colocated tasks compete for shared resources. As tasks are heterogeneous, the resulting performance dependencies are complex. In our previous work [18] we proposed a new combinatorial optimization model that uses two parameters of a task - its size and its type - to characterize how a task influences the performance of other tasks allocated to the same machine. In this paper, we study the egalitarian optimization goal: maximizing the worst-off performance. This problem generalizes the classic makespan minimization on multiple processors (P||Cmax). We prove that polynomially-solvable variants of multiprocessor scheduling are NP-hard and hard to approximate when the number of types is not constant. For a constant number of types, we propose a PTAS, a fast approximation algorithm, and a series of heuristics. We simulate the algorithms on instances derived from a trace of one of Google clusters. Algorithms aware of jobs' types lead to better performance compared with algorithms solving P||Cmax. The notion of type enables us to model degeneration of performance caused by using standard combinatorial optimization methods. Types add a layer of additional complexity. However, our results - approximation algorithms and good average-case performance - show that types can be handled efficiently.Comment: Author's version of a paper published in Euro-Par 2017 Proceedings, extends the published paper with addtional results and proof

    The management of academic workloads: full report on findings

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    The pressures on UK higher education (from explicit competition and growth in student numbers, to severe regulatory demands) are greater than ever, and have resulted in a steady increase in measures taken by universities to actively manage their finances and overall quality. These pressures are also likely to have impacted on staff and, indeed, recent large surveys in the sector have indicated that almost half of respondents find their workloads unmanageable. Against this background it would seem logical that the emphasis on institutional interventions to improve finance and quality, should be matched by similar attention given to the allocation of workloads to staff, and a focus on how best to utilise people’s time - the single biggest resource available within universities. Thus the aim of this piece of research was to focus on the processes and practices surrounding the allocation of staff workloads within higher education. Ten diverse organisations were selected for study: six universities in the UK, two overseas universities and two non higher education (but knowledge-intensive) organisations. In each, a crosssection of staff was selected, and in-depth interviews carried out. A total of 59 such interviews were carried out across the ten organisations. By identifying typical practices, as well as interesting alternatives, views on the various strengths and weaknesses of each of their workload allocation approaches was collated; and associated factors requiring attention identified. Through an extensive process of analysis, approaches which promoted more equitable loads for individuals, and which might provide synergies for institutions were also investigated

    Scalable dimensioning of resilient Lambda Grids

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    This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit

    Facing the Future: Financing Productive Schools

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    Synthesizes the School Finance Redesign Project's findings on policy options for redesigning the system to focus resources on promoting student learning. Calls for student count-based funding, integrated data collection, innovation, and accountability

    School Finance Systems and Their Responsiveness to Performance Pressures: A Case Study of North Carolina

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    Details the mechanisms of and influences on the state's school finance system, changes caused by increased performance pressures, local officials' views on alternative allocation of resources, and obstacles to linking resources to student learning
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