MPI (Message Passing Interface) is a specification for a standard library for message passing that was defined by the MPI Forum, a broadly based group of parallel computer vendors, library writers, and applications specialists. Multiple implementations of MPI have been developed. In this paper, we describe MPICH, unique among existing implementations in its design goal of combining portability with high performance. We document its portability and performance and describe the architecture by which these features are simultaneously achieved. We also discuss the set of tools that accompany the free distribution of MPICH, which constitute the beginnings of a portable parallel programming environment. A project of this scope inevitably imparts lessons about parallel computing, the specification being followed, the current hardware and software environment for parallel computing, and project management; we describe those we have learned. Finally, we discuss future developments for MPICH, including those necessary to accommodate extensions to the MPI Standard now being contemplated by the MPI Forum. 1

In recent years, encouraged by today's fast workstations and by software systems designed to transform workstation clusters into parallel programming environments, network of workstations have been increasingly used as computational engines. Networked workstations, however, are not ideal replacements for supercomputers, because of the low interconnection capacity provided by current local area networks. In this paper, we present an application using the EcliPSe toolkit, a system for replication-based parallel processing in heterogeneous environments. Although primarily designed for replicative applications (that generally do not require large amounts of communication), EcliPSe can be used for more general forms of message-passing parallel processing. We describe the use of the toolkit in the parallelization of a cluster labeling algorithm. The algorithm is designed so that it uses some of EcliPSe's features to reduce communication overhead, making the algorithm suitable for execution o...

iv 1 SP Scheduler Policy Overview 1 2 SP Scheduler Users Guide 1 2.1 Terminology : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 1 2.2 Scheduler Commands : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 1 2.3 Getting Started : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 6 2.4 Supported Job Types : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 9 2.5 Using Temporary Storage on the SP Nodes with the Scheduler : : : : : : : : : : : : 12 2.6 Releasing Resources When Finished : : : : : : : : : : : : : : : : : : : : : : : : : : : 12 2.7 Current Queuing Algorithm : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 12 3 System Installation and Administration Guide 15 3.1 Installing the Scheduler : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 15 3.2 Modifying the Scheduler for a Specific Environment : : : : : : : : : : : : : : : : : : 28 3.3 Syste...