Haiyan Yu

Vega: A Computer Systems Approach to Grid Computing

Abstract In this paper, we contrast four approaches for Grid computing, and discuss a computer systems approach in detail. This approach views a Grid as a distributed computer system, and its main concerns are systems abstractions and constructs, such as the Grid equivalents of computer architecture, address space, process, device, file system, user/developer’s interface. Following this methodology, we identified several essential issues, developed a Vega Grid systems architecture, and proposed several systems techniques such as Grid routers, Grid address spaces, Grid process (grip), Grid community (agora), and a Grid Service Markup Language (GSML) software suite. We evaluated the computer systems approach and the associated techniques by discussing an OSGA-compliant Grid system software implementation and a travel agency example.

A Survey on Wireless Grids and Clouds

Wireless grid is a wireless network based virtual system that consists of wireless-connected different types of electronic devices and computers. It has broad application prospects in e-learning, mobile e-business, modern healthcare, smart home, wireless sensor networks and disaster management. Wireless cloud is a natural extension of wireless grid. On the basis of a literature analysis, this paper gives a category on wireless grids, and discusses the concept, characteristics and architectures of wireless grids. Then it presents a review on the existing work, mainly focusing on the issues of communication technologies, middleware and applications. At the end, the paper analyzes the open issues and lists the main research directions in this field. The survey indicates that the wireless grid and cloud is a vibrant research area.

An Efficient Hierarchical Clustering Method for Large Datasets with Map-Reduce

Large datasets become common in applications like Internet services, genomic sequence analysis and astronomical telescope. The demanding requirements of memory and computation power force data mining algorithms to be parallelized in order to efficiently deal with the large datasets. This paper introduces our experience of grouping internet users by mining a huge volume of web access log of up to 100 gigabytes. The application is realized using hierarchical clustering algorithms with Map-Reduce, a parallel processing framework over clusters. However, the immediate implementation of the algorithms suffers from efficiency problem for both inadequate memory and higher execution time. This paper present an efficient hierarchical clustering method of mining large datasets with Map-Reduce. The method includes two optimization techniques: “Batch Updating” to reduce the computational time and communication costs among cluster nodes, and “Co-occurrence based feature selection” to decrease the dimension of feature vectors and eliminate noise features. The empirical study shows the first technique can significantly reduce the IO and distributed communication overhead, reducing the total execution time to nearly 1/15. Experimentally, the second technique efficiently simplifies the features while obtains improved accuracy of hierarchical clustering.

System software for china national grid

The China National Grid project developed and deployed a suite of grid system software called CNGrid Software. This paper presents the features and implementation of the software suite from the viewpoints of grid system deployment, grid application developers, grid resource providers, grid system administrators, and the end users.

Abacus: a service-oriented programming language for grid applications

This paper presents Abacus, a service-oriented programming language designed for the development of grid applications. Abacus considers that all the grid resources constitute a unified logical address space, where each memory cell holds a resource in the form of a service, and a grid application solves a problem by operating on these memory cells. Abacus allows programmers to concentrate on the logic of their applications, such as service implementation logic, service invocation logic, and glue logic. Low-level details such as resource distribution, resource binding, and service deployment are supported by the compiler and the runtime system. With such virtualization techniques, Abacus helps to enhance the productivity of programmers in developing grid applications.

The GSML tool suite: a supporting environment for user-level programming in grids

The grid technology emerges for the need of resource sharing and cooperating in wide areas. In the OGSA framework, grid resources are abstracted as grid services in order to hide their distributed and heterogeneous properties. A grid service can be seen as a server-side interface that defines the access fashion of grid resources. To explore and utilize grid resources effectively and conveniently, we propose a user-level programming language called Grid Service Markup Language (GSML) to help end users describe their usage of grid services. The base of GSML is the CAM model, which abstracts the grid as a computer with active memories. When designing the GSML, we define several GSML tags to indicate the structure, the operation element of GSML pages and relations between operation elements. The key feature of GSML is using a special tag to mark up grid services. To support the running of a GSML page, we design a set of tools called the GSML tool suite to compose, execute and deploy GSML pages. In order to provide the physical-resource-independent property for GSML, we also propose the concepts of virtual resource space and community. As a user-level programming language, the GSML can be a complement to OGSA framework. A prototype to prove our concepts is also presented.

Virtual Organization Management in XtreemOS: an Overview

XtreemOS aims to build and promote a Linux based operating system to provide native Virtual Organization (VO) support in the next generation Grids. XtreemOS takes a different approach from many existing Grid middleware by: first, recognizing the fundamental role of VO in Grid computing and hence taking VO support into account from the very beginning of our design; and, second, getting around the overheads brought by layers of existing Grid middleware by enabling native VO support in the Linux operating system. This paper presents our vision of VOs in a Grid operating system and describes various aspects of VO management in our system architecture, ranging from lifecycle management, application execution management, security, to node-level enforcement mechanisms in operating system.

Operating System-Level Virtual Organization Support in XtreemOS

In computational grids, a virtual organization (VO) is a dynamic coupling of multiple Linux/Unix nodes for resource sharing under specific polices. Currently, VO support functionalities are generally implemented as grid middleware. However, the usability of grids is often impaired by the complexity of configuring and maintaining a new layer of security infrastructure as well as adapting to new interfaces of security enabled services. In this paper, we present an OS-level approach to provide native VO support functionalities, which is a part of XtreemOS project [18]. Our approach adopts pluggable frameworks existing in current OS as extension points to implement VO support, avoiding modification of kernel codes and easily turning traditional OSes into grid-aware ones. The performance evaluation of NAS parallel benchmarks (NPB) shows that our current implementation incurs trivial overhead on original systems.

An Approach to Debugging Grid or Web Services

In this paper, we first introduce some issues that are encountered in building a service debugger and briefly describe our approach to addressing them. Next, we outline some debugging modes and components of a simple composite debugger. Then, we mainly describe its message-based front-end and back-end, which are a co-existing, self-identifying, and non- intrusive. Finally, we preset some experimental results of our latest prototype.

BEAP: An End-User Agile Programming Paradigm for Business Applications

Business applications are subject to changes with technology trends or market demands. However, quick response to these changes is still a challenging issue. Most of the existing architectures (e.g., CORBA, Web Services) still expose the developers to excessive low-level details and force a tight coupling between program modules. For end users, developing, customizing, and reengineering applications remain difficult and time-consuming tasks. A high-level programming model is presented, together with a descriptive programming paradigm called BEAP, to facilitate end-user programming. In this approach, applications could be visually composed from well-defined software components called “funnels” in an event-driven fashion. Application examples have shown that, by raising the level of abstraction as well as simplifying the programming model, BEAP could empower end users to build business applications on demand with improved productivity.