Galaxies Collide On the I-Way: an Example of Heterogeneous Wide-Area Collaborative Supercomputing

As a part of the Supercomputing '95 High Performance Computing Challenge, the authors have used the re sources of three of the National Science Foundation (NSF) supercomputing centers as a single, distributed, heteroge neous metacomputer to carry out the largest simulation of colliding galaxies yet attempted. The metacomputer con sisted of the following machines: TMC CM-5, Cray C90/T3D, IBM SP-2, and SGI Power Challenge. This paper describes the scalable parallel numerical algorithms used to carry out the hybrid N-body/gas dynamical simulation, as well as the inter-MPP communication system the authors developed to connect them. The system, called sclib, is simple yet flexible, and consists of a network of communicating objects, or agents. Each communication agent is a process that resides on the front-end processor of a parallel supercomputer and brokers the interactions between the various components of the distributed com putation. The design is independent of host architecture and execution model yet takes advantage of scheduling resources local to the compute servers. As such, it serves as a useful prototype for future research in distributed, heterogeneous, high-performance computing.