Heterogeneous remote computing system for computational astrophysics with OmniRPC

We have developed a hybrid computing system named HMCS-G (Grid-enabled Heterogeneous Multi-Computer System) which combines multiple cluster systems and a special purpose machine for gravity calculations. The purpose of HMCS-G is to provide ideal computation environment for computational astrophysics, which requires multiple physics phenomena for precise and detailed simulation. There are two categories of machines required for this system, that is, multiple PC-clusters for general purpose computation such as hydro-dynamics and a special purpose machine GRAPE-6 which calculates gravity for all pairs of particles in the system with very high-speed. These systems are connected with a grid-RPC named OmniRPC which supports Globus and ssh for authentication. Our HMCS-G enables the worldwide access to GRAPE-6 cluster which provides several TFLOPS performance for gravity calculation. All participating PC-clusters share this resource in time sharing manner with grid technology. For efficient usage of GRAPE-6 resource, we modified the original server cluster of it for multiple clients running in various network environment. Currently, precise simulations on galaxy formation are being performed on clusters in several institutes with smoothed particle hydrodynamics and radiative transfer under complete gravity calculation, as the first real application on HMCS-G.