Checkpointing of parallel applications can be used as the core technology to provide process migration. Both, checkpointing and migration, are an important issue for parallel applications on networks of workstations. The CoCheck environment which we present in this paper introduces a new approach to provide checkpointing and migration for parallel applications. In difference to existing systems CoCheck rather sits on top of the message passing library than inside and achieves consistency at a level above the message passing system. It uses an existing single process checkpointer which is available for a wide range of systems. Hence, CoCheck can be easily adapted to both, different message passing systems and new machines.

: Access to high-performance computing power remains crucial for many computational chemistry problems. Unfortunately, traditional supercomputers or cluster computing solutions from commercial vendors remain very expensive, even for entry level configurations, and are therefore often beyond the reach of many small to medium-sized research groups and universities. Clusters of networked commodity computers provide an alternative computing platform that can offer substantially better price/performance than commercial supercomputers. We have constructed a networked PC cluster, or Beowulf, dedicated to computational chemistry problems using standard ab initio molecular orbital software packages such as Gaussian and GAMESS-US. This paper introduces the concept of Beowulf computing clusters and outlines the requirements for running the ab initio software packages used by computational chemists at the University of Adelaide. We describe the economic and performance trade-offs and design choi...

The essential idea of this paper is that one should not separate the method of computing the expected present value of a derivative from its ultimate computing topology. In the following sections, we discuss the costbenefit issues involved with implementing several methods for computing derivative statistics on alternate computing topologies. We show how the choice of topology impacts the computing time for a particular example of a time consuming derivative valuation. We conclude by showing how all these factors can be represented as a case-based expert system, which can be used to help an organization assess its computing alternatives. 1. Background: Algorithm Tradeoffs in Computing Derivatives We are concerned with the computational problem of deriving the expected value and other statistics of a derivative security f at time T 0 . When the underlying security S and derivative security f are modeled as stochastic processes, the problem can be solved by reformulating it as a bou...

Abstract — Advances in the Internet and telecommunications technologies have spurred many research efforts in integrated communication systems which integrate heterogeneous devices (such as desktop phone, cellular phone, PSTN phone or pager) and networks (like the Public Switch Telephone Network, cellular networks, or the pager networks) on top of the Internet and enables communications among any devices or service endpoints. In this paper, we explore the service creation model and framework for such a system, which allows easy, flexible and rapid communication service customization and extension. Keywords— Internet telephony, integrated communication systems, service creation model, user activity-based services, generic and high level state machines, system interface, system primitives, preference specification I.

A computer framework feasible for developing parallel systems according to the Bulk Synchronous Parallel (BSP) computing model is described: Switched Interconnection of Parallel Processors (Swipp). Demanding applications can be described as directed graphs where the interdependent subtasks constitute the nodes. The tasks are predistributed by a system master, Computer Executive Engine (CEE), to a set of heterogeneous computing nodes. Each computing node has a preprogrammed secondary control processor attached for performing communication and runtime tasks, thus allowing primary processors of various kinds and programming styles. Synchronization of a bulk of subactivities is done in locksteps by the CEE. Basic features are modelled by the Ptolemy framework and prototype modules are being implemented. I. INTRODUCTION The performance of sequential single CPU processors has been steadily increasing over the last decades due to circuit technology improvements. The von Neumann model of comp...

Parallel computing on a cluster of workstations and personal computers has very high potential since it leverages the existing hardware and software. Parallel programming environment offers the user a convenient way to express parallel computation and communication. A lot of work has been done in synthesizing distributed memory parallel machines from a cluster of workstations. However, such a parallel environment is not supported on a network of DOS machines. POENDOM,ParallelOperatingEnvironment on aNetwork of DOSMachines --- provides a master process for job mapping and configuration management and several slave processes for job spawning on client nodes in coordination with the master process. The MPL (MessagePassingLibrary) provided by POENDOM can be used to develop coarse grained parallel applications which can be executed in POENDOM environment. MPL supports message passing interfaces for point-to-point communication, collective communication, and for synchronization among differe...

This paper assesses the effectiveness of various approaches to realizing SSI clusters. We cover both workstation and SMP server clusters such as Berkeley NOW [2], Sun SolarisMC [7], and Digital TruCluster [4]. For comparison purposes, the Cray/SGI Origin 2000, a CC-NUMA (coherent cache non-uniform memory access) machine, and cluster-structured MPP (massively parallel processors) such as the IBM SP2 [1] are also included. Our study is based on present technology, standards, and application trends.

The unceasing development of the Internet technology currently revolutionizes the way we look for relevant information. Since the number of web pages is uncountable, and very disorganized, a powerful searching tool like Information Retrieval (IR) system is needed. In this paper, we propose a co-operative indexing system called "DSIR". Co-operative DSIR is a full text vector space based indexing system that have been designed to run on the network of low-cost PC workstations using MPI library. Preliminary retrieval experiments using multigigabyte TREC9's small web track collection reveals quite promising results. We believe that co-operative DSIR provides another solution to the dissemination and retrieval of innumerable web pages in terms of cost, efficiently, and timeliness. 1