Providing Access to High Performance Computing Technologies

This paper describes two projects underway to provide users with access to high performance computing technologies. One e ort, the National HPCC Software Exchange, is providing a single point of entry to a distributed collection of domain-speci c repositories. These repositories collect, catalog, evaluate, and provide access to software in their specialized domains. The NHSE infrastructure allows these repositories to interoperate with each other and with the top-level NHSE interface. Another e ort is the NetSolve project which is a client-server application designed to solve computational science problems over a network. Users may access NetSolve computational servers through C, Fortran, MATLAB, or World Wide Web interfaces. An interesting intersection between the two projects would be the use of the NetSolve system by a domain-speci c repository to provide access to software without the need for users to download and install the software on their own systems. 1 The National HPCC Software Exchange 1.1 Overview of the NHSE The National HPCC Software Exchange (NHSE) is an Internet-accessible resource that facilitates the exchange of software and of information among research and computational scientists involved with High Performance Computing and Communications (HPCC) [1] . The NHSE facilitates the development of discipline-oriented software repositories and promotes contributions to and use of such repositories by Grand Challenge teams, as well as other members of the high performance computing community. The expected bene ts from successful deployment of the NHSE include the following: { Faster development of better-quality software so that scientists can spend less time writing and debugging programs and more time on research problems. { Reduction of duplication of software development e ort by sharing of software. { Reduction of time and e ort spent in locating relevant software and information through the use of appropriate indexing and search mechanisms and domain-speci c expert help systems. 3 http://www.netlib.org/nhse/ { Reduction of duplication of e ort in evaluating software by sharing software review and evaluation information. The scope of the NHSE is software and software-related artifacts produced by and for the HPCC Program. Software-related artifacts include algorithms, speci cations, designs, and software documentation. The following three types of software being made available: { Systems software and software tools. This category includes parallel processing tools such as parallel compilers, message-passing communication subsystems, and parallel monitors and debuggers. { Basic building blocks for accomplishing common computational and communication tasks. These building blocks will be of high quality and transportable across platforms. Building blocks are meant to be used by Grand Challenge teams and other researchers in implementing programs to solve computational problems. Use of high-quality transportable components will speed implementation, as well as increase the reliability of computed results. { Research codes that have been developed to solve di cult computational problems. Many of these codes will have been developed to solve speci c problems and thus will not be reusable as is. Rather, they will serve as proofs of concept and as models for developing general-purpose reusable software for solving broader classes of problems. 1.2 Domain-speci c Repositories The e ectiveness of the NHSE will depend on discipline-oriented groups and Grand Challenge teams having ownership of domain-speci c software repositories. The information and software residing in these repositories will be best maintained and kept up-to-date by the individual disciplines, rather than by centralized administration. Domain experts are the best quali ed to evaluate, catalog, and organize software resources within their domain. Netlib { Mathematical Software An example of a domain-speci c repository is the Netlib mathematical software repository, which has been in existence since 1985 [2]. Netlib di ers from other publicly available software distribution systems, such as Archie, in that the collection is moderated by an editorial board and the software contained in it is widely recognized to be of high quality. Netlib distributes freely-available numerical libraries such as EISPACK, LINPACK, FFTPACK, and LAPACK that have long been used as important tools in scienti c computation. The Netlib collection also includes a large number of newer, less well-established codes. Software is available in all the major numerical analysis areas, including linear algebra, nonlinear equations, optimization, approximation, and di erential equations. Most of the software is written in Fortran, but programs in other languages, such as C and C++, are also available. Netlib uses the Guide to Available Mathematical Software (GAMS) classi cation system [3] to help users quickly locate software that meets their needs. A branch of Netlib specialized to high performance computing, called HPCnetlib, is currently under development. HPC-netlib will provide access to algorithms and software for both shared memory and distributed memory machines, as well as to information about performance of parallel numerical software on di erent architectures. PTLIB { Parallel Tools Another domain-speci c repository that is under development is the PTLIB parallel tools repository. PTLIB will provide access to high-quality tools in the followingareas: communication libraries, data parallel language compilers, automatic parallelization tools, debuggers and performance analyzers, parallel I/O, job scheduling and resource management. 1.3 Repository Interoperation In addition to providing access to its own software, a repository may wish to import software descriptions from other repositories and make this software available from its own interface. For example, a computational chemistry repository may wish to provide access to mathematical software and to parallel processing tools in a manner tuned to the computational chemistry discipline. A repository interoperation architecture is shown in Figure 1. import foreign metadata import foreign metadata import foreign metadata import foreign metadata export Netlib metadata export Softlib metadata export Argonne metadata export ORNL/CCS metadata