The application hosting environment: Lightweight middleware for grid-based computational science

Abstract

Grid computing is distributed computing performed transparently across multiple administrative domains. Grid middleware, which is meant to enable access to grid resources, is currently widely seen as being too heavyweight and, in consequence, unwieldy for general scientific use. Its heavyweight nature, especially on the clientside, has severely restricted the uptake of grid technology by computational scientists. In this paper, we describe the Application Hosting Environment (AHE) which we have developed to address some of these problems. The AHE is a lightweight, easily deployable environment designed to allow the scientist to quickly and easily run legacy applications on distributed grid resources. It provides a higher level abstraction of a grid than is offered by existing grid middleware schemes such as the Globus Toolkit. As a result the computational scientist does not need to know the details of any particular underlying grid middleware and is isolated from any changes to it on the distributed resources. The functionality provided by the AHE is 'application-centric': applications are exposed as web services with a well-defined standards-compliant interface. This allows the computational scientist to start and manage application instances on a grid in a transparent manner, thus greatly simplifying the user experience. We describe how a range of computational science codes have been hosted within the AHE and how the design of the AHE allows us to implement complex workflows for deployment on grid infrastructure.

Real science at the petascale

“…The sizes of these simulations were approximately 3 million atoms, two to three orders of magnitude larger than any previous atomistic clay mineral study. This was facilitated through a global infrastructure of federated gridbased computing resources (the US TeraGrid, the UK NGS and the EU DEISA (http://www.deisa.eu) grids) accessed through our lightweight hosting environment, the AHE (Coveney et al 2007). We find that the conformation of polymer adsorbed on the surface of the clay is distinct from that of polymer far from the surface, owing to complexation with the counterions found near the charged clay surface.…”

“…The simulation of ternary amphiphilic mixtures composed of oil, water and an amphiphilic species is performed using a kinetic LB implementation in the highly scalable, parallel MPI code LB3D (Love et al 2003). The code has built-in computational steering capabilities, has been hosted in the Application Hosting Environment (AHE; Coveney et al 2007) and has been deployed on various grid resources in the USA, UK and EU. Here, we report on the close-to-linear parallel scaling behaviour of LB3D on Ranger and on the new UK Cray XT4 machine, HECToR (http://www.hector.ac.uk/), in figure 3.…”

Automatic Service Deployment Using Virtualisation

“…OGSA-BES basic execution service implementations and JSDL job submission description language repositories) or other generic application wrappers (e.g. Application Hosting Environment (AHE) [4], Grid Execution Management for Legacy Code Application (GEMLCA) [5], Generic Application Service Factory (gFac) [9]). A specific interface is tuned for the application and written by either the application developers or by the user community.…”

The Application Hosting Environment: lightweight middleware for Grid based computational science

“…Computational steering applications [34,35], coupled model simulations [36,37] and workflows [38,39,40] are cases where applications and jobs can be clearly distinguished. In the initial AHE release, applications and jobs stand mainly in a one-to-one relationship except for the case of workflow applications.…”