Rick Bradshaw

Magellan: experiences from a science cloud

Cloud resources promise to be an avenue to address new categories of scientific applications including data-intensive science applications, on-demand/surge computing, and applications that require customized software environments. However, there is a limited understanding on how to operate and use clouds for scientific applications. Magellan, a project funded through the Department of Energys (DOE) Advanced Scientific Computing Research (ASCR) program, is investigating the use of cloud computing for science at the Argonne Leadership Computing Facility (ALCF) and the National Energy Research Scientific Computing Facility (NERSC). In this paper, we detail the experiences to date at both sites and identify the gaps and open challenges from both a resource provider as well as application perspective.

MPI Cluster System Software

We describe the use of MPI for writing system software and tools, an area where it has not been previously applied. By “system software” we mean collections of tools used for system management and operations. We describe the common methodologies used for system software development, together with our experiences in implementing three items of system software with MPI. We demonstrate that MPI can bring significant performance and other benefits to system software.

MPISH: a parallel shell for MPI programs

While previous work has shown MPI to provide capabilities for system software, actual adoption has not widely occurred. We discuss process management shortcomings in MPI implementations and their impact on MPI usability for system software and management tasks. We introduce MPISH, a parallel shell designed to address these issues.

An Interoperability Approach to System Software, Tools, and Libraries for Clusters

Systems software for clusters typically derives from a multiplicity of sources: the kernel itself, software associated with a particular distribution, site-specific purchased or open-source software, and assorted home-grown tools and procedures that attempt to glue everything together to meet the needs of the users and administrators of a particular cluster. Whether a cluster is a general-purpose resource serving multiple users or dedicated to a single application, getting everything to work together is a challenge. The challenge is partially met by special software distributions for clusters such as OSCAR or ROCKS. In this article, we discuss another approach (although it is not inconsistent with existing distributions), in which a small number of concepts are deployed to facilitate the customized integration of various software tools for cluster management, operation, and user jobs. The concepts include (1) a component approach to basic system software such as schedulers, queue managers, process managers, and monitors; (2) a software development kit for constructing networks of system software components, either from scratch or by wrapping “foreign” software, and (3) the use of explicit parallelism in building system tools for high performance. We illustrate this approach with a description of a mid-sized general-purpose cluster operated entirely by software built this way.

Disparity: Scalable Anomaly Detection for Clusters

In this paper, we describe disparity, a tool that does parallel, scalable anomaly detection for clusters. Disparity uses basic statistical methods and scalable reduction operations to perform data reduction on client nodes and uses these results to locate node anomalies. We discuss the implementation of disparity and present results of its use on a SiCortex SC5832 system.

A Composition Environment for MPI Programs

While MPI is the most common mechanism for expressing parallelism, MPI programs are not composable by using current MPI process managers or parallel shells. We introduce MPISH2, an MPI process manager analogous to serial Unix shells. It allows the composition of MPI and serial Unix utilities with one another to perform scalable tasks across large numbers of Unix clients. This paper discusses in detail issues of process management and parallel tool composition.

MPISH2: unix integration for MPI programs

While MPI is the most common mechanism for expressing parallelism, MPI programs remain poorly integrated in Unix environments. We introduce MPISH2, an MPI process manager analogous to serial Unix shells. It provides better integration capabilities for MPI programs by providing a uniform execution mechanism for parallel and serial programs, exposing return codes and standard I/O stream information.