Mark M. Morgan

Support for extensibility and site autonomy in the Legion grid system object model

Grid computing is the use of large collections of heterogeneous, distributed resources (including machines, databases, devices, and users) to support large-scale computations and wide-area data access. The Legion system is an implementation of a software architecture for grid computing. The basic philosophy underlying this architecture is the presentation of all grid resources as components of a single, seamless, virtual machine. Legions architecture was designed to address the challenges of using and managing wide-area resources. Features of the architecture include: global, shared namespaces; support for heterogeneity; security; wide-area data sharing; wide-area parallel processing; application-adjustable fault tolerance; efficient scheduling and comprehensive resource management. We present the core design of the Legion architecture, with focus on the critical issues of extensibility and site autonomy. Grid systems software must be extensible because no static set of system-level decisions can meet all of the diverse, often conflicting, requirements of present and future user communities, nor take best advantage of unanticipated future hardware advances. Grid systems software must also support complete site autonomy, as resource owners will not turn control of their resources over to a dictatorial system.

Genesis II - Standards Based Grid Computing

In the past years, hype over Web services and their uses in emerging software applications has prompted the creation of many standards and proto-standards. The OGF has seen a number of standards making their way through design and edit pipelines. While this standards process progresses, it is important that implementations of these standards develop in parallel in order to validate the efforts of the standards authors while also providing feedback for further specification refinement. No specification exists in isolation but rather composes with others to form higher order products. These specifications will form the grid infrastructure of the future and an evaluation of this emerging work becomes increasingly relevant. Genesis II is a grid system implemented using these standards that serves both to provide the feedback described above as well as to function as a production level grid system for research at the University of Virginia.

An early evaluation of WSRF and WS-Notification via WSRF.NET

The Web Services Resource Framework (WSRF) and its companion WS-Notification were introduced in January 2004 as a new model on which to build grids. This paper contains early observations made while implementing the full suite of WSRF and WS-Notification specifications on the Microsoft .NET Platform. While the potential of WSRF and WS-Notification remains strong, initial observations are that there are many challenges that remain to be solved, most notably the implied programming model derived from the specifications, particularly the complexity of service-side and client-code and the complexity of WS-Notification.

An Open Grid Services Architecture Primer

To expand the use of distributed computer infrastructures as well as facilitate grid interoperability, OGSA has developed standards and specifications that address a range of scenarios, including high-throughput computing, federated data management, and service mobility.

GFFS — THE XSEDE GLOBAL FEDERATED FILE SYSTEM

Federated, secure, standardized, scalable, and transparent mechanism to access and share resources, particularly data resources, across organizational boundaries that does not require application modification and does not disrupt existing data access patterns has been needed for some time in the computational science community. The Global Federated File System (GFFS) addresses this need and is a foundational component of the NSF-funded eXtreme Science and Engineering Discovery Environment (XSEDE) program. The GFFS allows user applications to access (create, read, update, delete) remote resources in a location-transparent fashion. Existing applications, whether they are statically linked binaries, dynamically linked binaries, or scripts (shell, PERL, Python), can access resources anywhere in the GFFS without modification (subject to access control). In this paper we present an overview of the GFFS and its most common use cases: accessing data at an NSF center from a home or campus, accessing data on a camp...

Summary: Integration of Legacy Grid Systems with Emerging Grid Standards

The open grid services architecture (OGSA) addresses the need for standardization of diverse grid services by defining a set of core capabilities and behaviors needed by loosely coupled, service-oriented grid architectures. These OGSA standards and interfaces are based on ubiquitous, platform-neutral, technologies like SOAP, XML, and Web services. This paper briefly describes our OGSA proxy implementation that interconnects legacy Legion grids with grids that support the emerging OGSA specifications. Specifically we have constructed proxy services that support OGSA-ByteIO, WS-Directory, and WS-Naming