Advances in storage and high-speed broadband communication network technologies are making it feasible to design and implement distributed scalable video-on-demand server networks. In this paper a hierarchical structu...
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Advances in storage and high-speed broadband communication network technologies are making it feasible to design and implement distributed scalable video-on-demand server networks. In this paper a hierarchical structure for a server network is proposed to support a metropolitan TV-Anytime service. A key issue, how to map the media assets onto such a hierarchical server network, is addressed in this paper. The definition and heuristic methods for the solution of this new combinatorial optimization problem are presented. The mapping problem studied here addresses the management of media assets taking the storage capacity, communication bandwidth limitation and access pattern into account. The methods presented in this paper are based on parallel simulated annealing and are verified by the use of a set of benchmark instances. The results show that the methods provide a near to optimal performance in terms of the Quality of Service (QoS).
This paper addresses the potential benefit of sharing jobs between independent sites in a grid computing environment. Also the aspect of parallel multi-site job execution on different sites is discussed. To this end, ...
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ISBN:
(纸本)9780769515823
This paper addresses the potential benefit of sharing jobs between independent sites in a grid computing environment. Also the aspect of parallel multi-site job execution on different sites is discussed. To this end, various scheduling algorithms have been simulated for several machine configurations with different workloads which have been derived from real traces. The results showed that a significant improvement in terms of a smaller average response time is achievable. The usage of multi-site applications can additionally improve the results as long as the increase of the execution time due to communication overhead is limited to about 25%.
Distributed high-performance computing (so-called metacomputing) refers to the coordinated use of a pool of geographically distributed high-performance computers. The user's view of an ideal metacomputer is that o...
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Distributed high-performance computing (so-called metacomputing) refers to the coordinated use of a pool of geographically distributed high-performance computers. The user's view of an ideal metacomputer is that of a powerful monolithic virtual machine. The implementor's view, on the other hand, is that of a variety of interacting services implemented in a scalable and extensible manner. We present MOL, the Metacomputer Online environment. In contrast to other metacomputing environments, MOL is not based on specific programming models or tools. It has rather been designed as an open, extensible software system comprising a variety of software modules, each of them specialized in serving one specific task such as resource scheduling, job control, task communication, task migration, user interface, and much more. All of these modules exist and are working. The main challenge in the design of MOL lies in the specification of suitable, generic interfaces for the effective interaction between the modules.
Exponentially growing capacities of disk drives have increased the problem that not only a complete disk can fail, but also individual, small groups of sectors can be erroneous. These sector errors are especially crit...
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Exponentially growing capacities of disk drives have increased the problem that not only a complete disk can fail, but also individual, small groups of sectors can be erroneous. These sector errors are especially critical during RAID rebuilds because they can only be detected when the corresponding sectors are read. Mechanisms to cope with sector errors, therefore, have become an important way to improve disk reliability. One approach to deal with sector errors is the introduction of intra-disk redundancy, where additional redundancy blocks are calculated and stored for each set of disk sectors. Previous studies have introduced intra-disk redundancy schemes and have evaluated their impact on disk reliability. None of these studies has evaluated the influence on disk drive performance or the underlying energy consumption. The study presented in this paper benchmarks existing schemes concerning these metrics. It shows the surprising result that weaker codes combined with newly introduced scrambling techniques can produce faster layouts with similar reliability properties than previously proposed strong codes.
The next generation grid applications demand grid middleware for a flexible negotiation mechanism supporting various ways of quality-of-service (QoS) guarantees. In this context, a QoS guarantee covers simultaneous al...
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The next generation grid applications demand grid middleware for a flexible negotiation mechanism supporting various ways of quality-of-service (QoS) guarantees. In this context, a QoS guarantee covers simultaneous allocations of various kinds of different resources, such as processor runtime, storage capacity, or network bandwidth, which are specified in the form of service level agreements (SLA). Currently, a gap exists between the capabilities of grid middleware and the underlying resource management systems concerning their support for QoS and SLA negotiation. In this paper we present an approach which closes this gap. Introducing the architecture of the virtual resource manager, we highlight its main QoS management features like run-time responsibility, co-allocation, and fault tolerance.
The next generation Grid will demand the Grid middleware to provide flexibility, transparency, and reliability. This implies the appliance of service level agreements to guarantee a negotiated level of quality of serv...
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ISBN:
(纸本)9780780384309
The next generation Grid will demand the Grid middleware to provide flexibility, transparency, and reliability. This implies the appliance of service level agreements to guarantee a negotiated level of quality of service. These requirements also affect the local resource management systems providing resources for the Grid. At this a gap between these demands and the features of today's resource management systems becomes apparent. In this paper we present an approach which closes this gap. Introducing the architecture of the virtual resource manager we highlight its main features of runtime responsibility, resource virtualization, information hiding, autonomy provision, and smooth integration of existing resource management system installations.
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