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

Abstract not found

This paper describes an overall framework for the design of numerical libraries on a computational Grid of processors where the processors may be geographically distributed and under the control of a Grid-based scheduling system. A set of experiments are presented in the context of solving systems of linear equations using routines from the ScaLAPACK software collection along with various grid service components, such as Globus, NWS, and Autopilot. Motivation On The Grid The goal of the Grid Application Development Software (GrADS) project [1] is to simplify distributed heterogeneous computing in the same way that the World Wide Web simplified information sharing over the Internet. The GrADS project is exploring the scientific and technical problems that must be solved to make Grid applications development and performance tuning for real applications an everyday practice. This requires research in four key areas; each validated in a prototype infrastructure that will make programming on grids a routine task: 1. Grid software architectures that facilitate information flow and resource negotiation among applications, libraries, compilers, linkers, and runtime systems; 2. Base software technologies, such as scheduling, resource discovery, and communication, to support development and execution of performance-efficient Grid applications; 3. Languages, compilers, environments, and tools to support creation of applications for the Grid and solution of problems on the Grid; and 4. Mathematical and data structure libraries for Grid applications, including numerical methods for control of accuracy and latency tolerance.

We make two observations about communications middleware: first, most middleware are similar, the differences are in their interfaces and optimizations; second, neither a fixed set of abstractions nor a fixed implementation of a set of abstractions is likely to be sufficient and well-performing for all applications. Based on these observations, we present Quarterware, a customizable middleware architecture. It abstracts basic middlware functionality, and admits application specific specializations and extensions. We demonstrate its flexibility by deriving implementations for core facilities of CORBA, RMI, and MPI. The performance results show that the derived implementations equal or exceed the performance of corresponding native versions. These results suggest that customizing middleware on a per-application basis is an effective approach for building robust, highperformance applications. 1 Introduction Communications middleware abstract common properties of an application domain a...

This paper describes current activities of the MPI-2 Forum. The MPI-2 Forum is a group of parallel computer vendors, library writers, and application specialists working together to define a set of extensions to MPI (Message Passing Interface). MPI was defined by the same process and now has many implementations, both vendor-proprietary and publicly available, for a wide variety of parallel computing environments. In this paper we present the salient aspects of the evolving MPI-2 document as it now stands. We discuss proposed extensions and enhancements to MPI in the areas of dynamic process management, one-sided operations, collective operations, new language binding, real-time computing, external interfaces, and miscellaneous topics. 1 Introduction During 1993 and 1994, a group of parallel computer vendors, library writers, and application scientists met regularly to define a standard interface for message-passing libraries. The result of this effort was MPI (Message-Passing Interfa...

Increasingly complex problems in many areas of today's scientific research demand new magnitudes of compute power. Top of the line supercomputers can merely provide for a fraction of the resources required by many computationally intensive projects currently undertaken at research institutions around the world. On the other hand, a vast amount of personal computers and workstations, many more powerful than a supercomputer was 10 years ago, sit idle or utilize their resources to generate screensaver images while their user is away.

1 1 Quick Start 1 2 Obtaining and Unpacking the Distribution 3 3 Documentation 5 4 Conguring mpich 5 4.1 Building a production mpich . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.2 Preparing mpich for TotalView debugging . . . . . . . . . . . . . . . . . . . 16 4.3 What if there is no Fortran compiler? . . . . . . . . . . . . . . . . . . . . . 16 4.4 Conguring with the Absoft Fortran Compiler . . . . . . . . . . . . . . . . . 16 4.5 Fortran 90 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.6 Special issues for heterogeneous networks . . . . . . . . . . . . . . . . . . . 17 4.7 Conguring with ssh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5 Compiling mpich 18 5.1 Getting tcl, tk, and wish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 5.2 Building multiple devices or architectures . . . . . . . . . . . . . . . . . . . 19 6 Running an MPI Program 19 7 MPE Library 19 7.1 Congure Options . . . . . . . ....

MPICH is an implementation of the MPI specification for a standard message-passing library interface. In this article we focus on the lessons learned from preparing MPICH for diverse parallel computing environments. These lessons include how to prepare software for configuration in unknown environments; how to structure software to absorb contributions by others; how to automate the preparation of man pages, Web pages, and other documentation; how to automate prerelease testing for both correctness and performance; and how to manage the inevitable problem reports with a minimum of resources for support.

This paper presents a taxonomy of parallel theorem-proving methods based on the control of search (e.g., master-slaves versus peer processes), the granularity of parallelism (e.g., fine, medium and coarse grain) and the nature of the method (e.g., ordering-based versus subgoalreduction) . We analyze how the di#erent approaches to parallelization a#ect the control of search: while fine and medium-grain methods, as well as master-slaves methods, generally do not modify the sequential search plan, parallel-search methods may combine sequential search plans (multi-search) or extend the search plan with the capability of subdividing the search space (distributed search). Precisely because the search plan is modified, the latter methods may produce radically di#erent searches than their sequential base, as exemplified by the first distributed proof of the Robbins theorem generated by the Modified Clause-Di#usion prover Peers-mcd. An overview of the state of the field and directions...

The cost of high-performance parallel platforms prevents parallel processing techniques from spreading in present applications. Networks of Workstations (NOW) exploiting off-the-shelf communication hardware, high-end PCs and standard communication software provide much cheaper but poorly performing parallel platforms. In our NOW prototype called GAMMA (Genoa Active Message MAchine) every node is a PC running a Linux operating system kernel enhanced with efficient communication mechanisms based on the Active Message paradigm. Active Messages supply virtualization of the network interface close enough to the raw hardware to guarantee good performance. The preliminary performance measures obtained by GAMMA show how competitive such a cheap NOW is. 1 Introduction Historically Local Area Network (LAN) device drivers in the Operating System (OS) kernel of a workstation have never been optimized like other devices whose performance is critical for user applications (such as disk drivers, memo...