Accessing Grid Metadata through a Web Interface

Accessing Grid Metadata through a Web Interface

Salvatore Scifo (Cometa Consortium, Italy)
DOI: 10.4018/978-1-60566-184-1.ch028
OnDemand PDF Download:


This chapter focuses on the efforts to design and develop a standard pure Java API to access the metadata service of the EGEE Grid middleware, and provide at the same time a powerful object oriented framework to allow engineers and programmers to embed metadata features inside their own application, using a standard approach based on design patterns. A specific web interface is built on top of this framework that permits users and administrators to manage the metadata catalog, from any platform and everywhere, according to their own X.509-based credentials.
Chapter Preview


This work is closely linked to the metadata service of the gLite, the middleware of the EGEE Grid European project. Within the gLite architecture, the data management system (DMS) is an essential part that enables users and applications to handle data and metadata without referring to the complex details of the computing environment. DMS provides APIs and Client tools to store, locate, access, retrieve and move files dispersed on the distributed virtual File System. From the functional point of view, gLite DMS offers two fundamental macro features: file management and metadata management. The first one (performed by the file catalogue service and the storage resource manager), involves the storing abilities (save file, copy file, read file, list file), placing abilities (replica file, transfer file) and security stuff (ACL for files, users roles). The second one (implemented by the metadata catalogue), offers database schema virtualization (metadata handling, intelligent search), file cataloguing and file searching. Figure 1 shows data management system modules and their interrelations.

Figure 1.

DMS architecture view

Key Terms in this Chapter

Framework: It is a basic conceptual structure used to solve or address complex issues. A software framework is a re-usable design for a software system (or subsystem). A software framework may include support programs, code libraries, a scripting language, or other software to help develop and glue together the different components of a software project. Various parts of the framework may be exposed through an API or be themselves API.

Provisioning: The allocation of resources to consumers on demand. A system determines specific need of the consumer and provides the resources as requested.

Middleware: A computer software that connects software components or applications. The software consists of a set of enabling services that allow multiple processes running on one or more machines to interact across a network. This technology evolved to provide for interoperability in support of the move to coherent distributed architectures, which are used most often to support and simplify complex, distributed applications. It includes web servers, application servers, and similar tools that support application development and delivery. Middleware is especially integral to modern information technology based on XML, SOAP, Web services, and service-oriented architecture.

API: An application programming interface is a set of declarations of the functions (or procedures) that an operating system, library or service provides to support requests made by computer programs. Language-dependent APIs are available only in a particular programming language. They utilize the syntax and elements of the programming language to make the API convenient to use in this particular context. Language-independent APIs are written in a way that means they can be called from several programming languages. This is a desired feature for a service-style API which is not bound to a particular process or system and is available as a remote procedure call.

Design Pattern: In software engineering, it is a general reusable solution to a commonly occurring problem in software design. A design pattern is not a finished design that can be transformed directly into code. It is a description or template for how to solve a problem that can be used in many different situations. Object-oriented design patterns typically show relationships and interactions between classes or objects, without specifying the final application classes or objects that are involved. Algorithms are not thought of as design patterns, since they solve computational problems rather than design problems. Not all software patterns are design patterns. Design patterns deal specifically with problems at the level of software design. Other kinds of patterns, such as architectural patterns, describe problems and solutions that have alternative scopes.

X.509: In cryptography, is an ITU-T standard for a public key infrastructure (PKI) and Privilege Management Infrastructure (PMI). X.509 specifies, amongst other things, standard formats for public key certificates, certificate revocation lists, attribute certificates, and a certification path validation algorithm.

Metadata: (meta data, or sometimes meta-information) is “data about data”, of any sort in any media. An item of metadata may describe an individual datum, or content item, or a collection of data including multiple content items. The word meta comes from the Greek, where it means ‘after’ or ‘beyond’. In epistemology, the word means “about (its own category)”; thus metadata is “data about the data”. Metadata is used to facilitate the understanding, characteristics, and management usage of data. The metadata required for effective data management varies with the type of data and context of use. In a library, where the data is the content of the titles stocked, metadata about a title would typically include a description of the content, the author, the publication date and the physical location.

Virtualization: A form of abstraction that provides location- and technology-transparent access of resources to the consumer. It decouples the tight connections between providers and consumers of resources, thus allowing sharing of the same resources by multiple users as needs arise.

Object Model: A collection of objects or classes through which a program can examine and manipulate some specific parts of its world. In other words, the object-oriented interface to some service or system. Such an interface is said to be the object model of the represented service or system.

Applications Grid: It shares and reuses application code but uses software technologies like service oriented architectures that facilitate sharing business logic among multiple applications.

Information Grid: This grid shares information across multiple consumers and applications. It unlocks fragmented data from proprietary applications by treating information as a resource to be shared across the grid.

Infrastructure Grid: This grid pools, shares and reuses infrastructure resources such as hardware, software, storage and networks across multiple applications.

Grid Computing: A style of computing that dynamically pools IT resources together for use based on resource need. It allows organizations to provision and scale resources as needs arise, thereby preventing the underutilization of resources (computers, networks, data archives, instruments).

Complete Chapter List

Search this Book:
Editorial Advisory Board
Table of Contents
Ruth E. Shaw
Emmanuel Udoh, Frank Zhigang Wang
Emmanuel Udoh
Chapter 1
Emmanuel Udoh, Frank Zhigang Wang, Vineet R. Khare
This chapter presents a historical record of the advent of Grid with a recourse to some basic definitions commonly accepted by most researchers. It... Sample PDF
Overview of Grid Computing
Chapter 2
Eric Aubanel
The problem of load balancing parallel applications is particularly challenging on computational grids, since the characteristics of both the... Sample PDF
Resource-Aware Load Balancing of Parallel Applications
Chapter 3
Enis Afgan, Purushotham Bangalore
Grid computing has emerged as the next generation computing platform. Because of the resource heterogeneity that exists in the grid environment... Sample PDF
Assisting Efficient Job Planning and Scheduling in the Grid
Chapter 4
Kuo-Chan Huang, Po-Chi Shih, Yeh-Ching Chung
Most current grid environments are established through collaboration among a group of participating sites which volunteer to provide free computing... Sample PDF
Effective Resource Allocation and Job Scheduling Mechanisms for Load Sharing in a Computational Grid
Chapter 5
Tevfik Kosar
As the data requirements of scientific distributed applications increase, the access to remote data becomes the main performance bottleneck for... Sample PDF
Data-Aware Distributed Batch Scheduling
Chapter 6
Gianni Pucciani, Flavia Donno, Andrea Domenici, Heinz Stockinger
Data replication is a well-known technique used in distributed systems in order to improve fault tolerance and make data access faster. Several... Sample PDF
Consistency of Replicated Datasets in Grid Computing
Chapter 7
Ming Wu, Xian-He Sun
Rapid advancement of communication technology has changed the landscape of computing. New models of computing, such as business-on-demand, Web... Sample PDF
Quality of Service of Grid Computing
Chapter 8
QoS in Grid Computing  (pages 75-83)
Zhihui Du, Zhili Cheng, Xiaoying Wang, Chuang Lin
This chapter first summarizes popular terms of QoS related concepts and technologies in grid computing, including SLA, End-to-End QoS Provision and... Sample PDF
QoS in Grid Computing
Chapter 9
Kris Bubendorfer, Ben Palmer, Ian Welch
A Grid resource broker is the arbiter for access to a Grid’s computational resources and therefore its performance and functionality has a... Sample PDF
Trust and Privacy in Grid Resource Auctions
Chapter 10
Sandro Fiore, Alessandro Negro, Salvatore Vadacca, Massimo Cafaro, Giovanni Aloisio, Roberto Barbera
Grid computing is an emerging and enabling technology allowing organizations to easily share, integrate and manage resources in a distributed... Sample PDF
An Architectural Overview of the GRelC Data Access Service
Chapter 11
Man Wang, Zhihui Du, Zhili Cheng
Resource Management System (RMS), which manages the Grid resources and matches the applications’ requests to the proper resources, is one of the... Sample PDF
Adaptive Resource Management in Grid Environment
Chapter 12
Vineet R. Khare, Frank Zhigang Wang
The need for a dynamic and scalable expansion of the grid infrastructure and resources and other scalability issues in terms of execution efficiency... Sample PDF
Bio-Inspired Grid Resource Management
Chapter 13
Yuhui Deng, Frank Zhigang Wang, Na Helian
Storage Grid is a new model for deploying and managing the heterogeneous, dynamic, large-scale, and geographically distributed storage resources.... Sample PDF
Service Oriented Storage System Grid
Chapter 14
Dominic Cherry, Maozhen Li, Man Qi
This chapter presents MediaGrid, a distributed storage system for archiving broadcast media contents. MediaGrid utilizes storage resources donated... Sample PDF
A Distributed Storage System for Archiving Broadcast Media Content
Chapter 15
Maozhen Li, Man Qi, Bin Yu
The computational grid is rapidly evolving into a service-oriented computing infrastructure that facilitates resource sharing and large-scale... Sample PDF
Service Discovery with Rough Sets
Chapter 16
Irfan Habib, Ashiq Anjum, Richard McClatchey
Due to some barriers to adoption we have not seen a proliferation of Grid Computing technologies throughout e-Science or other domains. This chapter... Sample PDF
On the Pervasive Adoption of Grid Technologies: A Grid Operating System
Chapter 17
Kurt Vanmechelen, Jan Broeckhove, Wim Depoorter, Khalid Abdelkader
As grid computing technology moves further up the adoption curve, the issues of dealing with conflicting user requirements formulated by different... Sample PDF
Pricing Computational Resources in Grid Economies
Chapter 18
Rosario M. Piro
Large, geographically distributed and heterogeneous computing infrastructures, such as the Grid, often span multiple organizations and... Sample PDF
Resource Usage Accounting in Grid Computing
Chapter 19
Frans Arickx, Jan Broeckhove, Peter Hellinckx, David Dewolfs, Kurt Vanmechelen
Quantum structure or scattering calculations often belong to a class of computational problems involving the aggregation of a set of matrices... Sample PDF
Grid-Based Nuclear Physics Applications
Chapter 20
Gabriel Aparicio, Fernando Blanco, Ignacio Blanquer, César Bonavides, Juan Luis Chaves, Miguel Embid, Álvaro Hernández
In the last years an increasing demand for Grid Infrastructures has resulted in several international collaborations. This is the case of the EELA... Sample PDF
Developing Biomedical Applications in the Framework of EELA
Chapter 21
Gerald Schaefer, Roger Tait
Efficient approaches to computationally intensive image processing tasks are currently highly sought after. In this chapter, the authors show how a... Sample PDF
Distributed Image Processing on a Blackboard System
Chapter 22
Daniele Andreotti, Armando Fella, Eleonora Luppi
The BaBar experiment uses data since 1999 in examining the violation of charge and parity (CP) symmetry in the field of high energy physics. This... Sample PDF
Simulated Events Production on the Grid for the BaBar Experiment
Chapter 23
Diego Liberati
A framework is proposed that creates, uses, and communicates information, whose organizational dynamics allows performing a distributed cooperative... Sample PDF
A Framework for Semantic Grid in E-Science
Chapter 24
Roberto Barbera, Valeria Ardizzone, Leandro Ciuffo
The Grid INFN virtual Laboratory for Dissemination Activities (GILDA) is a fully working Grid test-bed devoted to training and dissemination... Sample PDF
Grid INFN Virtual Laboratory for Dissemination Activities (GILDA)
Chapter 25
Dirk Gorissen, Tom Dhaene, Piet Demeester, Jan Broeckhove
The simulation and optimization of complex systems is a very time consuming and computationally intensive task. Therefore, global surrogate modeling... Sample PDF
Grid Enabled Surrogate Modeling
Chapter 26
Patrik Skogster
Grid computing is becoming as essential part of different business analysis. In traditional business computing infrastructures data transfer occurs... Sample PDF
GIS Grids and the Business Use of GIS Data
Chapter 27
Gokop Goteng, Ashutosh Tiwari, Rajkumar Roy
The emerging grid technology provides a secured platform for multidisciplinary experts in the security intelligence profession to collaborate and... Sample PDF
Grid Computing: Combating Global Terrorism with the World Wide Grid
Chapter 28
Salvatore Scifo
This chapter focuses on the efforts to design and develop a standard pure Java API to access the metadata service of the EGEE Grid middleware, and... Sample PDF
Accessing Grid Metadata through a Web Interface
Chapter 29
Jyotsna Sharma
Efforts in Grid Computing, both in academia and industry, continue to grow rapidly worldwide for research, scientific and commercial purposes.... Sample PDF
Grid Computing Initiatives in India
Chapter 30
Hai Jin, Li Qi, Jie Dai, Yaqin Luo
A grid system is usually composed of thousands of nodes which are broadly distributed in different virtual organizations. Owing to geographical... Sample PDF
Dynamic Maintenance in ChinaGrid Support Platform
About the Contributors