Wrapping MPI-based legacy codes as Java/CORBA components

Techniques for wrapping an MPI-based molecular dynamics (MD) simulation cod e as Java/CORBA components, for use within a distributed component based pr oblem solving environment (CB-PSE), is presented. A legacy code for simulat ing a Lennard-Jones fluid is first wrapped as a single CORBA object, follow ed by division of the code into computational sub-units, where each sub-uni t is wrapped as a CORBA object containing MPI calls, and run on a cluster o f workstations - enabling different MPI implementations to inter-operate. U sing a Java implementation, users can submit simulation tasks through a Web based inter-face, without needing to know implementation details of the le gacy code, or the exact interaction between sub-units within the code. We p rovide performance comparisons of wrapping the entire MD code as a single o bject versus wrapping sub-units within it, and offer a simple performance m odel to explain our findings. (C) 2001 Elsevier Science B.V. All rights res erved.