5,240 research outputs found
Algorithms for advance bandwidth reservation in media production networks
Media production generally requires many geographically distributed actors (e.g., production houses, broadcasters, advertisers) to exchange huge amounts of raw video and audio data. Traditional distribution techniques, such as dedicated point-to-point optical links, are highly inefficient in terms of installation time and cost. To improve efficiency, shared media production networks that connect all involved actors over a large geographical area, are currently being deployed. The traffic in such networks is often predictable, as the timing and bandwidth requirements of data transfers are generally known hours or even days in advance. As such, the use of advance bandwidth reservation (AR) can greatly increase resource utilization and cost efficiency. In this paper, we propose an Integer Linear Programming formulation of the bandwidth scheduling problem, which takes into account the specific characteristics of media production networks, is presented. Two novel optimization algorithms based on this model are thoroughly evaluated and compared by means of in-depth simulation results
AliEnFS - a Linux File System for the AliEn Grid Services
Among the services offered by the AliEn (ALICE Environment
http://alien.cern.ch) Grid framework there is a virtual file catalogue to allow
transparent access to distributed data-sets using various file transfer
protocols. (AliEn File System) integrates the AliEn file catalogue as
a new file system type into the Linux kernel using LUFS, a hybrid user space
file system framework (Open Source http://lufs.sourceforge.net). LUFS uses a
special kernel interface level called VFS (Virtual File System Switch) to
communicate via a generalised file system interface to the AliEn file system
daemon. The AliEn framework is used for authentication, catalogue browsing,
file registration and read/write transfer operations. A C++ API implements the
generic file system operations. The goal of AliEnFS is to allow users easy
interactive access to a worldwide distributed virtual file system using
familiar shell commands (f.e. cp,ls,rm ...) The paper discusses general aspects
of Grid File Systems, the AliEn implementation and present and future
developments for the AliEn Grid File System.Comment: 9 pages, 12 figure
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