Virtualizing access to scientific applications with the Application Hosting Environment

The growing power and number of high performance computing resources made available through computational grids present major opportunities as well as a number of challenges to the user. At issue is how these resources can be accessed and how their power can be effectively exploited. In this paper we first present our views on the usability of contemporary high-performance computational resources. We introduce the concept of grid application virtualization as a solution to some of the problems with grid-based HPC usability. We then describe a middleware tool that we have developed to realize the virtualization of grid applications, the Application Hosting Environment (AHE), and describe the features of the new release, AHE 2.0, which provides access to a common platform of federated computational grid resources in standard and non-standard ways. Finally, we describe a case study showing how AHE supports clinical use of whole brain blood flow modelling in a routine and automated fashion.Program summaryProgram title: Application Hosting Environment 2.0Catalogue identifier: AEEJ_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEJ_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: GNU Public Licence, Version 2No. of lines in distributed program, including test data, etc.: not applicableNo. of bytes in distributed program, including test data, etc.: 1 685 603 766Distribution format: tar.gzProgramming language: Perl (server), Java (Client)Computer: x86Operating system: Linux (Server), Linux/Windows/MacOS (Client)RAM: 134 217 728 (server), 67 108 864 (client) bytesClassification: 6.5External routines: VirtualBox (server), Java (client)Nature of problem: The middleware that makes grid computing possible has been found by many users to be too unwieldy, and presents an obstacle to use rather than providing assistance [1,2]. Such problems are compounded when one attempts to harness the power of a grid, or a federation of different grids, rather than just a single resource on the grid.Solution method: To address the above problem, we have developed AHE, a lightweight interface, designed to simplify the process of running scientific codes on a grid of HPC and local resources. AHE does this by introducing a layer of middleware between the user and the grid, which encapsulates much of the complexity associated with launching grid applications.Unusual features: The server is distributed as a VirtualBox virtual machine. VirtualBox (http://www.virtualbox.org) must be downloaded and installed in order to run the AHE server virtual machine. Details of how to do this are given in the AHE 2.0 Quick Start Guide.Running time: Not applicableReferences:[1]J. Chin, P.V. Coveney, Towards tractable toolkits for the grid: A plea for lightweight, useable middleware, NeSC Technical Report, 2004, http://nesc.ac.uk/technical_papers/UKeS-2004-01.pdf.[2]P.V. Coveney, R.S. Saksena, S.J. Zasada, M. McKeown, S. Pickles, The Application Hosting Environment: Lightweight middleware for grid-based computational science, Computer Physics Communications 176 (2007) 406–418.