Visual Grid Workflow in Triana

In this paper, we describe the graphical abstractions for Grids and services that have been implemented within the Triana problem solving environment. We provide an overview of the ways in which Triana interacts with services (e.g., Web and P2P services) and then how we interact with core Grid components, such as resource managers and data management systems through the extensive use of the GridLab GAT interface. We describe in detail the GAT philosophy and implementation and then show how the various GAT primitives can be represented in an intuitive fashion within a Triana workflow. This approach, which we refer to as the Visual GAT, differs substantially from other approaches because we do not tie our implementation to any specific underlying Grid middleware technologies; rather, we base our implementation on application level requirements and model such primitives from a user’s perspective by hiding as much complexity as possible without undermining the core capabilities required. We provide a use case to demonstrate the Visual GAT implementation and show how legacy applications can seamlessly be distributed and integrated in a dynamic fashion within complex data-driven workflow scenarios.     

Autonomic oil reservoir optimization on the Grid

The emerging Grid infrastructure and its support for seamless and secure interactions is enabling a new generation of autonomic applications where the application components, Grid services, resources, and data interact as peers to manage, adapt and optimize themselves and the overall application. In this paper we describe the design, development and operation of a prototype of such an application that uses peer‐to‐peer interactions between distributed services and data on the Grid to enable the autonomic optimization of an oil reservoir. Copyright © 2005 John Wiley & Sons, Ltd.     

Zorilla: a peer‐to‐peer middleware for real‐world distributed systems

The inherent complex nature of current distributed computing architectures hinders the widespread adoption of these systems for mainstream use. In general, users have access to a highly heterogeneous set of compute resources, which may include clusters, grids, desktop grids, clouds, and other compute platforms. This heterogeneity is especially problematic when running parallel and distributed applications. Software is needed which easily combines as many resources as possible into one coherent computing platform. In this paper, we introduce Zorilla: peer‐to‐peer (P2P) middleware that creates a single distributed environment from any available set of compute resources. Zorilla imposes minimal requirements on the resource used, is platform independent, and does not rely on central components. In addition to providing functionality on bare resources, Zorilla can exploit locally available middleware. Zorilla explicitly supports distributed and parallel applications, and allows resources from multiple sites to cooperate in a single computation. Zorilla makes extensive use of both virtualization and P2P techniques. We will demonstrate how virtualization and P2P combine into a simple design, while enhancing functionality and ease of use. Together, these techniques bring our goal a step closer: transparent, easy use of resources, even on very heterogeneous distributed systems. Copyright © 2011 John Wiley & Sons, Ltd.     

ICENI: Optimisation of component applications within a Grid environment

Effective exploitation of Computational Grids can only be achieved when applications are fully integrated with the Grid middleware and the underlying computational resources. Fundamental to this exploitation is information. Information about the structure and behaviour of the application, the capability of the computational and networking resources, and the availability and access to these resources by an individual, a group or an organisation.

In this paper we describe Imperial College e-Science Networked Infrastructure (ICENI), a Grid middleware framework developed within the London e-Science Centre. ICENI is a platform-independent framework that uses open and extensible XML derived protocols, within a framework built using Java and Jini, to explore effective application execution upon distributed federated resources. We match a high-level application specification, defined as a network of components, to an optimal combination of the currently available component implementations within our Grid environment, by using composite performance models. We demonstrate the effectiveness of this architecture through the high-level specification and solution of a set of linear equations by automatic and selection of optimal resources and implementations.     

GridLab—a grid application toolkit and testbed

In this paper we present the new project called GridLab which is funded by the European Commission under the Fifth Framework Programme. The GridLab project, made up of computer scientists, astrophysicists and other scientists from various application areas, will develop and implement the grid application toolkit (GAT) together with a set of services to enable easy and efficient use of Grid resources in a real and production grid environment. GAT will provide core, easy to use functionality through a carefully constructed set of generic higher level grid APIs through which an application will be able to call the grid services laying beneath in order to perform efficiently in the Grid environment using various, dramatically wild application scenarios.     

Writing programs that run EveryWare on the Computational Grid

The Computational Grid has been proposed, for the implementation of high-performance applications using widely dispersed computational resources. The goal of a Computational Grid is to aggregate ensembles of shared, heterogeneous, and distributed resources (potentially controlled by separate organizations) to provide computational, "power" to an application program. We provide a toolkit for the development of globally deployable Grid applications. The toolkit, called EveryWare, enables an application to draw computational power transparently from the Grid. It consists of a portable set of processes and libraries that can be incorporated into an application so that a wide variety of dynamically changing distributed infrastructures and resources can be used together to achieve supercomputer-like performance. We provide our experiences gained while building the EveryWare toolkit prototype and an explanation of its use in implementing a large-scale Grid application     

An End-to-end Workflow Pipeline for Large-scale Grid Computing

In this paper we describe a service-based, software architecture that enables end-to-end, high-level workflow processing in a Grid environment consisting of many heterogeneous resources. Our architecture is essentially a pipeline that extends from the abstract application specification phase to the deployment and execution stages through to returning the results to the user. We envision a large-scale Grid environment that contains heterogeneous resources. Our architecture caters for flexible deployment, performance, reliability and charging for resource usage. These are addressed at the specification level as well as at the realisation (brokering) and execution levels. The proposed architecture is derived from previous work in LeSC that has produced the ICENI pipeline, and our experience with e-Science projects, such as GENIE, e-Protein and RealityGrid from which we derive a set of key requirements.     

Resource Space Grid: model,method and platform

A Resource Space Grid is a virtual Grid that aims at effectively sharing, using and managing versatile resources across the Internet. The kernel of the Resource Space Grid includes a Resource Space Model (RSM) and a uniform Resource Using Mechanism (RUM). This paper presents the Resource Space Grid's core scientific issues and methodology, architecture, model and theory, design criteria and method, and practice. A normal form theory is proposed to normalize the resource space—a coordinate system for uniformly specifying and organizing resources. The RUM provides not only the end‐users with an operable resource browser to operate resources using the built‐in Resource Operation Language (ROL), but also the application developers with the ROL‐based programming environment. The prototype platform based on the proposed model and method has been implemented and used for sharing and managing resources in distributed research teams. Operations on Resource Spaces can constitute the virtual communities of Resource Space Grids—a platform independent resource sharing environment. Copyright © 2004 John Wiley & Sons, Ltd.     

Studying protein folding on the Grid: experiences using CHARMM on NPACI resources under Legion

One benefit of a computational Grid is the ability to run high‐performance applications over distributed resources simply and securely. We demonstrated this benefit with an experiment in which we studied the protein‐folding process with the CHARMM molecular simulation package over a Grid managed by Legion, a Grid operating system. High‐performance applications can take advantage of Grid resources if the Grid operating system provides both low‐level functionality as well as high‐level services. We describe the nature of services provided by Legion for high‐performance applications. Our experiences indicate that human factors continue to play a crucial role in the configuration of Grid resources, underlying resources can be problematic, Grid services must tolerate underlying problems or inform the user, and high‐level services must continue to evolve to meet user requirements. Our experiment not only helped a scientist perform an important study, but also showed the viability of an integrated approach such as Legion's for managing a Grid. Copyright © 2004 John Wiley & Sons, Ltd.     

Analysis and Provision of QoS for Distributed Grid Applications

Grid computing provides the infrastructure necessary to access and use distributed resources as part of virtual organizations. When used in this way, Grid computing makes it possible for users to participate in collaborative and distributed applications such as tele-immersion, visualization, and computational simulation. Some of these applications operate in a collaborative mode, requiring data to be stored and delivered in a timely manner. This class of applications must adhere to stringent real-time constraints and Quality-of-Service (QoS) requirements. A QoS management approach is therefore required to orchestrate and guarantee the timely interaction between such applications and services. We discuss the design and a prototype implementation of a QoS system, and demonstrate how we enable Grid applications to become QoS compliant. We validate this approach through a case study of an image processing task derived from a nanoscale structures application.     

Standards-Based Job Management in Grid Systems

The Grid paradigm for accessing heterogeneous distributed resources proved to be extremely effective, as many organizations are relying on Grid middlewares for their computational needs. Many different middlewares exist, the result being a proliferation of self-contained, non interoperable “Grid islands”. This means that different Grids, based on different middlewares, cannot share resources, e.g. jobs submitted on one Grid cannot be forwarded for execution on another one. To address this problem, standard interfaces are being proposed for some of the important functionalities provided by most Grids, namely job submission and management, authorization and authentication, resource modeling, and others. In this paper we review some recent standards which address interoperability for three types of services: the BES/JSDL specifications for job submission and management, the SAML notation for authorization and authentication, and the GLUE specification for resource modeling. We describe how standards-enhanced Grid components can be used to create interoperable building blocks for a Grid architecture. Furthermore, we describe how existing components from the gLite middleware have been re-engineered to support BES/JSDL, GLUE and SAML. From this experience we draw some conclusions on the strengths and weaknesses of these specifications, and how they can be improved.     

A survey on approaches to gridification

The Grid shows itself as a globally distributed computing environment, in which hardware and software resources are virtualized to transparently provide applications with vast capabilities. Just like the electrical power grid, the Grid aims at offering a powerful yet easy‐to‐use computing infrastructure to which applications can be easily ‘plugged’ and efficiently executed. Unfortunately, it is still very difficult to Grid‐enable applications, since current tools force users to take into account many details when adapting applications to run on the Grid. In this paper, we survey some of the recent efforts in providing tools for easy gridification of applications and propose several taxonomies to identify approaches followed in the materialization of such tools. We conclude this paper by describing common features among the proposed approaches, and by pointing out open issues and future directions in the research and development of gridification methods. Copyright © 2007 John Wiley & Sons, Ltd.     

The Virtual Laboratory: a toolset to enable distributed molecular modelling for drug design on the World‐Wide Grid

Computational Grids are emerging as a new paradigm for sharing and aggregation of geographically distributed resources for solving large‐scale compute and data intensive problems in science, engineering and commerce. However, application development, resource management and scheduling in these environments is a complex undertaking. In this paper, we illustrate the development of a Virtual Laboratory environment by leveraging existing Grid technologies to enable molecular modelling for drug design on geographically distributed resources. It involves screening millions of compounds in the chemical database (CDB) against a protein target to identify those with potential use for drug design. We have used the Nimrod‐G parameter specification language to transform the existing molecular docking application into a parameter sweep application for executing on distributed systems. We have developed new tools for enabling access to ligand records/molecules in the CDB from remote resources. The Nimrod‐G resource broker along with molecule CDB data broker is used for scheduling and on‐demand processing of docking jobs on the World‐Wide Grid (WWG) resources. The results demonstrate the ease of use and power of the Nimrod‐G and virtual laboratory tools for grid computing. Copyright © 2003 John Wiley & Sons, Ltd.     

Architecting and implementing distributed Web applications using the graph‐oriented approach

This paper presents a graph‐oriented framework, called WebGOP, for architecture modeling and programming of Web‐based distributed applications. WebGOP is based on the graph‐oriented programming (GOP) model, under which the components of a distributed program are configured as a logical graph and implemented using a set of operations defined over the graph. WebGOP reshapes GOP with a reflective object‐oriented design, which provides powerful architectural support in the World Wide Web environment. In WebGOP, the architecture graph is reified as an explicit object which itself is distributed over the network, providing a graph‐oriented context for the execution of distributed applications. The programmer can specialize the type of graph to represent a particular architecture style tailored for an application. WebGOP also has built‐in support for flexible and dynamic architectures, including both planned and unplanned dynamic reconfiguration of distributed applications. We describe the WebGOP framework, a prototypical implementation of the framework on top of SOAP, and a performance evaluation of the prototype. The prototype demonstrated the feasibility of our approach. Results of the performance evaluation showed that the overhead introduced by WebGOP over SOAP is reasonable and acceptable. Copyright © 2003 John Wiley & Sons, Ltd.     

开放网格服务体系结构OGSA及其仿真应用

该文对目前网格最新的体系结构一开放网格服务体系结构OGSA进行了介绍，该体系结构基于Web Selwices框架提出了一种网格服务结构的思想。OGSA的服务功能主要包括动态服务创建、服务发现、生命周期管理、注册和通知等。分布式仿真系统与网格有许多相似之处，同时基于HLA标准建立的分布仿真系统又存在着很多有待完善之处，所以提出将网格技术结合到仿真系统的设计中，建立基于网格的分布式仿真系统。基于OGSA的结构特点，这种新的仿真系统以建立标准的仿真服务为中心，同时实现了对仿真资源的动态分配和调度，增强了系统的可重用性和灵活性。     

REMUS: A Rerouting and Multiplexing System for Grid Connectivity Across Firewalls

The Grid provides unique opportunities for high-performance computing through distributed applications that execute over multiple remote resources. Participating institutions can form a virtual organization to maximize the utilization of collective resources as well as to facilitate collaborative projects. However, there are two design aspects in distributed environments like the Grid that can easily clash: security and resource sharing. It may be that resources are secure but are not entirely conducive to resource sharing, or networks are wide open for resource sharing but sacrifice security as a result. We developed REMUS, a rerouting and multiplexing system that provides a compromise through connection rerouting and wrappers. REMUS reroutes connections using proxies, ports and protocols that are already authorized across firewalls, avoiding the need to make new openings through the firewalls. We also encapsulate applications within wrappers, transparently rerouting the connections among Grid applications without modifying their programs. In this paper, we describe REMUS and the tests we conducted across firewalls using two Grid middleware case studies: Globus Toolkit 2.4 and Nimrod/G 3.0.     

An integration experience of a software architecture and a monitoring infrastructure to deploy applications with non‐functional requirements in computing grids

Resource management is an important aspect to consider regarding applications that might have different non‐functional or operational requirements, when running in distributed and heterogeneous environments. In this context, it is necessary to provide the means to specify the required resource constraints and an infrastructure that can adapt the applications in light of the changes in resource availability. We adopted a contract‐based approach to describe and maintain parallel applications that have non‐functional requirements in a Computing Grid context, called ZeliGrid. To form the supporting infrastructure we have designed a software architecture that integrates some of the Globus services, the LDAP and the NWS monitoring services. Some modules that map the contract approach into software artifacts were also integrated to this architecture. This paper addresses the architecture and integration issues of our approach, as well as how we put the pieces together highlighting deployment and implementation details, which have to consider diverse aspects such as monitoring, security and dynamic reconfiguration. Copyright © 2010 John Wiley & Sons, Ltd.     

基于Web服务的网格体系结构及其支撑环境研究

网格技术是当前网络计算的前沿领域,基于Web服务技术构建网格系统有助于提高网格系统的可扩展性和互操作能力,是这一领域中的最新热点.但现有的工作尚未明确界定基于Web服务的网格的功能模型和实现机制.首先讨论了网格功能模型,基于OGSA(open grid service architecture)框架提出了基于Web服务的网格层次体系结构,并将Web服务工作流引入到网格任务描述中,给出一种Web服务与网格技术相融合的机制,介绍了基于Web服务的网格支撑环境WebSASE4G的总体结构和设计原理,为基于Web     

A Grid-based Virtual Reactor: Parallel performance and adaptive load balancing

We address the problem of porting parallel distributed applications from static homogeneous cluster environments to dynamic heterogeneous Grid resources. We introduce a generic technique for adaptive load balancing of parallel applications on heterogeneous resources and evaluate it using a case study application: a Virtual Reactor for simulation of plasma chemical vapour deposition. This application has a modular architecture with a number of loosely coupled components suitable for distribution over the Grid. It requires large parameter space exploration that allows using Grid resources for high-throughput computing. The Virtual Reactor contains a number of parallel solvers originally designed for homogeneous computer clusters that needed adaptation to the heterogeneity of the Grid. In this paper we study the performance of one of the parallel solvers, apply the technique developed for adaptive load balancing, evaluate the efficiency of this approach and outline an automated procedure for optimal utilization of heterogeneous Grid resources for high-performance parallel computing.     

MAGDA: A Mobile Agent based Grid Architecture

Mobile agents mean both a technology and a programming paradigm. They allow for a flexible approach which can alleviate a number of issues present in distributed and Grid-based systems, by means of features such as migration, cloning, messaging and other provided mechanisms. In this paper we describe an architecture (MAGDA – Mobile Agent based Grid Architecture) we have designed and we are currently developing to support programming and execution of mobile agent based application upon Grid systems.