Message-passing environments for metacomputing

In this paper, we present the three libraries PACX-MPI, PLUS, and PVMPI that provide message-passing between different high-performance computers in metacomputing environments. Each library supports the development and execution of distributed metacomputer applications.

The PACX-MPI approach offers a transparent interface for the communication between two or more MPI environments. PVAMPI allows the user spawning parallel processes under the MPI environment. The PLUS protocol bridges the gap between vendor-specific (e.g., MPL, NX, and PARIX) and vendor-independent message-passing environments (e.g., PVM and MPI). Moreover, it offers the ability to create and control processes at application runtime.     

Web based metacomputing

Programming tools that are simultaneously sustainable, highly functional, robust and easy to use have been hard to come by in the HPCC arena. This is partially due to the difficulty in developing sophisticated customized systems for what is a relatively small part of the worldwide computing enterprise. Thus, we have developed a new strategy – termed High Performance Commodity Computing (HPCC) [G. Fox, W. Furmanski, HPCC as high performance commodity computing, in: I. Foster, C. Kesselman (Eds.), Building National Grid, http://www.npac.syr.edu/users/gcf/HPcc/HPcc.html] – which builds HPCC programming tools on top of the remarkable new software infrastructure being built for the commercial web and distributed object areas. We add high performance to commodity systems using multi-tier architecture with Globus metacomputing toolkit as the backend of a middle-tier of commodity web and object servers. We have demonstrated the fully functional prototype of WebFlow during Alliance’98 meeting.     

PARDIS: Programmer-level abstractions for metacomputing

The potential offered by metacomputing is hard to realize due to the complexity of programming geographically distributed applications spanning different software systems. This paper describes PARDIS, a system designed to address this challenge, based on ideas underlying the Common Object Request Broker Architecture (CORBA), a successful industry standard. PARDIS is a distributed environment in which objects representing data-parallel computations, called Single Program Multiple Data (SPMD) objects, as well as non-parallel objects present in parallel programs, can interact with each other across platforms and software systems. Each of these objects represents a small encapsulated application and can be used as a building block in the construction of powerful distributed metaapplications. The objects interact through interfaces specified in the Interface Definition Language (IDL), which allows the programmer to integrate within one metaapplication component implemented using different software systems. Further, support for non-blocking interactions between objects allows PARDIS to build concurrent distributed scenarios.     

流程工业生产执行系统的软件基础设施

结合流程工业环境苛刻,生产过程复杂等特点,针对传统MES存在的环境适应性低、研发和维护成本高和应用效果不理想等问题,提出基于模型驱动架构软件开发方法的软件基础设施,用于构建下一代柔性MES。其总体目标是使MES在满足流程工业普适性需求的同时,也能适应特定的企业环境。基于层次化设计,系统分为CIM、PIM和PSM。在PIM软件基础设施之上,CIM又包括3个领域模型:功能模型分析需求并描述功能,逻辑模型使用自描述的建模方法,定义工厂对象模型、用户接口和工作流程,科学计算模型将工厂对象模型转换为数学模型,最终实现数据协调和生产优化的闭环管理。原型验证及工程实践表明,系统能够实现与传统MES相一致的领域模型,并显著缩短产品交付时间,降低项目成本。本文将领域建模过程和软件开发过程彻底分离,提高了软件抽象层次和复用度。与之前的MDA相比,系统更具运行时动态特征,领域模型能够在编译期后被方便地修改,使UML等设计工具的输出不再仅仅是文档,而成为可执行的产物。     

Towards a theory of multimedia metacomputing

Multimedia metacomputing is a new approach to the management and processing of multimedia data in web-based information systems. It offers high flexibility and openness while shielding the applications from any system internals. Starting with the vision of a completely open and globally distributed multimedia information system, we consider abstraction concepts required, especially transformation independence, and an appropriate semantic model.Thus, the major focus of this paper is on the abstract data and processing model called VirtualMedia,¹ which provides a transformation independence framework for multimedia processing. In particular, we describe how transformation requests are represented and processed, exploiting semantic equivalence relations on filter graphs and redundant materialization, finally yielding instantiatable plans for materializing the requested media object(s) at the client.     

WAMM in the framework of graphical user interfaces for metacomputing management

Current environments for metacomputing generally have tools for managing the resources of a metacomputer but often lack adequate tools for designing, writing, and executing programs. Building an application for a metacomputer typically involves writing source codes on a local node, transferring and compiling codes on every node, and starting their execution. Without such tools, the application development phases can come up against considerable difficulties. In order to alleviate these problems, some graphical user interfaces (GUIs) based on PVM, such as XPVM, Parallel Application Development Environment (PADE) and Wide Area Metacomputing Manager (WAMM) have been implemented. These GUIs integrate a programming environment which facilitates the user in performing the application development phases and the application execution.

This paper outlines the general requirements for designing GUIs for metacomputing management, and compares WAMM, a graphical user interface, with some related works.     

ARC: a metacomputing environment for clusters augmented with reconfigurable hardware

The addition of reconfigurable hardware (FPGAs) to the nodes of Beowulf-style clusters has the potential to accelerate a variety of parallel applications through a combination of parallel programming and reconfigurable computing techniques. However, making efficient use of the computational resources available places a significant burden on the application developer due to the lack of support for reconfigurable computing and task heterogeneity in standard message-passing libraries. This paper describes Accessible Reconfigurable Computing (ARC), a metacomputing environment designed to address these issues. The architecture, implementation, and operation of the system are described in detail.     

A component-based approach to build a portable and flexible middleware for metacomputing

The huge amount of computing resources in the Internet makes it possible to build metacomputers for solving large-scale problems. Despite the great availability of software infrastructures for managing such systems, metacomputer programming is often based on models that do not appear to be suitable to run applications on wide-area, unreliable, highly-variable networks of computers. In this paper, we present a customisable, Java-based middleware which provides programmers with a portable and flexible framework to run applications over a hierarchical, virtual network architecture. The middleware is designed according to a component-based approach that enables the execution behaviour of each computing node to be customised in order to satisfy application needs. The paper shows some examples of programming model customisation and demonstrates that flexibility can be achieved without significantly compromising performance.     

Standards for the information infrastructure

Many standards groups and consortia are now addressing global information infrastructure (GII) standardization. Each group is working on issues within its particular GII area, and some are aggressively promoting government activities, commercial mergers, and social concerns. In many cases, essential standards already exist but are unknown to other groups that could benefit from their use     

Near-real-time satellite image processing: metacomputing in CC++

Metacomputing combines heterogeneous system elements in a seamless computing service. In this case study, we introduce the elements of metacomputing and describe an application for cloud detection and visualization of infrared and visible-light satellite images. The application processes the satellite images by using Compositional C++ (CC++)-a simple, yet powerful extension of C++-and its runtime system, Nexus, to integrate specialized resources, high-speed networks, parallel and distributed computing, and stereoscopic visualization in virtual reality (VR) displays     

The network weather service: a distributed resource performance forecasting service for metacomputing

The goal of the Network Weather Service is to provide accurate forecasts of dynamically changing performance characteristics from a distributed set of metacomputing resources. Providing a ubiquitous service that can both track dynamic performance changes and remain stable in spite of them requires adaptive programming techniques, an architectural design that supports extensibility, and internal abstractions that can be implemented efficiently and portably. In this paper, we describe the current implementation of the NWS for Unix and TCP/IP sockets and provide examples of its performance monitoring and forecasting capabilities.     

A support infrastructure for the smart kindergarten

Continuing progress in microelectronics has allowed the embedding of sensing, processing, and wireless communications capabilities in familiar physical objects. This enables the creation of smart environments, where communication and computation technologies facilitate interactions between people and their surroundings, instead of just person-to-person or person-to-server communication. In a collaborative project underway at the University of California, Los Angeles, called Smart Kindergarten (SmartKG), we are exploring these technologies in a sensor-instrumented environment for early childhood education. Spatially dense but unobtrusive sensors continuously capture interactions among students, teachers, and common classroom objects. The sensors deliver observations wirelessly to a wired infrastructure for analysis and storage. Two crucial building blocks of this environment are Sylph, a sensor middleware infrastructure, and iBadge, a lightweight sensor-instrumented badge worn by students and teachers.     

Heuristics for railway infrastructure saturation

This research concerns the problem of the evaluation of the railway infrastructure capacity. It is an important question when railway authorities have to choose between different infrastructure investment projects. We developped independently two heuristic approaches to solve the infrastructure saturation problem. The first is based on a constraint programming model which is solved using a greedy heuristic. The second approach identifies the saturation problem as a unicost set packing problem and its resolution is ensured by an adaption of GRASP metaheuristic. Currently, both resolution techniques are not in competition. The goal is to grasp the resolution ability of the heuristics and to analyse the kind of solutions produced. The Pierrefitte-Gonesse junction has been used as experimental support. A software environment allows to simulate several timetables involving TGV, Inter City and Freight trains.     

An infrastructure for smart hospitals

In healthcare facilities most of the daily activities require strict coordination between clinicians, who often operate under heavy workloads and minimal workforce conditions in environments filled with increasingly complex technology. Ubiquitous Computing applications constitute a suitable solution for both reducing medical costs and improving patient safety by better supporting clinical processes. In this study we introduce an intelligent infrastructure for smart hospitals which implements basic services to optimize medical staff/patient interactions and grants ubiquitous and transparent access to clinical data stored in standard clinical databases. This infrastructure relies on the integration of Radio Frequency IDentification (RFID) and photosensor technologies to identify, locate and track clinicians and patients equipped with mobile devices and wearable RFID tags.     

A metacomputing environment for demanding applications: design, implementation, experiments and business benefit

The paper describes the design, implementation, and use of a commercial metacomputing environment for computationally intensive loosely-coupled parallel applications. Much weight has been laid on practical and commercialisation aspects, and on business benefit. This distinguishes this work from many other metacomputing activities in a positive way. It demonstrates how a metacomputing environment can be used to improve a company’s position in the market. A cluster of networked geographically dispersed computing nodes is considered as physical layer. The proposed distribution of work over the nodes of the execution network is proven optimal, in terms of minimizing the execution time, with respect to the availability of resources. We also present our experience on testing the environment for computing-intensive 3D-rendering jobs derived from the ESPRIT project EROPPA and demonstrate that the new environment can change dramatically the character of the post production business.     

Wireless middleware: glue for the mobile infrastructure

The need for participants to communicate across so many platforms has led to the rise in wireless middleware's importance. Middleware is a software layer that resides between programs, OSs, hardware platforms, and communications protocols. Middleware lets different applications and systems, including clients and servers on different platforms, work together. Wireless middleware eases the transformation of markup languages, the delivery of content and data, protocol and device recognition, the incorporation and routing of business logic through enterprise systems, and the adaptation of data formats for compatibility with multiple databases.     

Simplified infrastructure for the transformation of XML models

An approach is proposed to the construction of a lightweight infrastructure for the model driven development of complex software systems. It is based on the use of a domain-dependent XML format for primary models. A model has a compact representation, allows using advanced tools for changing and extending it, and makes it possible to easily determine transformations for converting domain-dependent XML models into any other models. The use of XLS to describe transformations allows organizing both vertical and horizontal transformations (with any number of abstraction layers).