Practical Experience from Porting and Executing the Wien2k Application on the EGEE Production Grid Infrastructure

Abstract

While the Grid promises to deliver a large number of computation nodes to a user, this computation power is not usable without the proper adaption of the application for the Grid. In this paper, we describe the methods used to port and execute a particular application, Wien2k, on the EGEE production Grid. First, the process of porting the application is described. Then, we investigate the measures necessary to execute the application in this production Grid environment efficiently. Although the focus is on this special application, we describe generic methods which can be applied to all applications. We specifically address: Creating a workflow from an application and mapping this workflow to a Grid workflow using the activity attraction pattern. We discuss workflow engines which support cycles in their application workflow. We investigate naive and worker scheduling techniques. A short introduction into licensing on the Grid is given. Optimisation techniques such as deployment re-use are discussed. Different data transfer mechanisms, centralised data transfer, data re-use, storage element data transfer, and peer-to-peer data transfer are compared. The paper is concluded with suggestions for further workflow porting.