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Meeting to see demonstrations and discuss |
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Meeting to see demonstrations and discuss |
Speakers:
Peter Coveney, James Suter, Radhika Saksena
Centre for Computational Science, UCL
We shall present a discussion of the design, implementation and applications of two web service based hosting environments: WEDS (Web services based Environment for Distributed Simulations) for use in an single administrative domain and AHE (Application Hosting Environment) for use across administrative domains. We shall include a demonstration and a hands-on session using applications hosted using the WEDS system.
Web services have the potential to radically enhance the ability of researchers to make use of distributed computing. We have adopted a lightweight approach to middleware design to produce a hosting environment for use within an administrative domain built on WSRF::Lite, called WEDS (WSRF Environment for Distributed Simulation). WEDS can be downloaded from http://www.realitygrid.org/WEDS
WEDS is a hosting environment for distributed simulation, a powerful and simple middleware scheme designed to let scientists remotely deploy single or multiple instances of a pre-existing codes across multiple resources and giving steering, visualisation and workflow functionality with only simple modifications to program code. WEDS therefore is able to facilitate access to local grid resources and handles aspects of job submission, steering, visualisation and workflow manipulation. The web services nature of WEDS allows these services to exist across platform, architecture and geographical boundaries.
WEDS is lightweight middleware. It is easy to use and install on the client side by ordinary users, requiring little effort on behalf of the system administrator. This is in contrast to existing "heavy-weight" alternatives such as Condor and the Globus ToolKit, which require significant effort to build, install and maintain. Only standard libraries (Perl, SOAP etc) are required for successful implementation. WEDS can be installed in a user specified directory.
WEDS allows scientists to launch and interact with their applications and has been produced in close collaboration between application scientists and developers, in contrast to the "heavyweight" alternatives.
Examples of codes which have been hosted within the WEDS environment are the molecular dynamics codes NAMD, LAMMPS, DL_POLY_3 and the lattice Boltzmann fluid dynamics code LB2D and LB3D. This list is not extensive; It should be possible for any code which can be compiled on a resource to be included within the WEDS environment. In the Machine Evaluation Workshop we will demonstrate the hosting of molecular dynamics codes NAMD and LAMMPS using WEDS.
WEDS has been designed for low complexity grids, especially within administrative domains. In the Machine Evaluation Workshop we shall introduce the Application Hosting Environment (AHE), which has been designed to provide the simplest possible service interface to a client for submitting a job to highly complex grids. This raises additional security concerns, which are dealt with using WS-security and transport layer security (TLS).
The AHE will interface with GridSAM, an OMII funded job submission and monitoring service. GridSAM can interact with GlobusTookKit and Condor on the resource side. Therefore the AHE can interact in a clear transparent way with complex grid architecture and submission systems such as queuing systems without interaction from the client.