ShanghaiGrid: Towards Building Shared Information Platform Based on Grid1 Ying Li1,2, Minglu Li1, and Jiadi Yu1 1
Department of Computer Science and Engineering, Shanghai JiaoTong University , Shanghai 200030, China 2 Computer Science and Technology School, Soochow University,Suzhou 215006,China {liying, li-ml, jdyu}@cs.sjtu.edu.cn,
[email protected]
Abstract. Compared with Computational Grid, the Information Grid currently has no clearly definition. In terminology of the Shanghai Information Grid, to meet the requirement of Information Grid, we design a QoS-aware Information Service which can provide efficient search ability and reliable Index Service and the Information Grid Portal which acts as an access point to Information Grid.
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Background
Shanghai is a municipality of eastern China at the mouth of the Yangtze River. Today, it has become the largest economic center and important port city in China. The primary goal of ShanghaiGrid is to develop a set of system software for the Information Grid and establish an infrastructure for the grid-based applications. By means of flexible, secure, open standards sharing and coordinating of computational resources, data information and dedicated services among virtual organizations, this project will build an Information Grid tailored for the characteristics of Shanghai and support the typical applications[1]. Information Grid currently has no clear definition. The ShanghaiGrid gives users and applications secure access to any information anywhere over any type of network [2] and integrates heterogeneous information on the web into a homogenous presentation. The terminology of the Shanghai Information Grid is a Grid environment that provides information to the end users rather than provides computational power, data access, and storage resources which are the key activities in Computational Grid. The rest of the paper introduces our research on the Information Service and Grid Portal of Information Grid. 1
This paper is supported by 973 project (No.2002CB312002) of China, grand project (No.03dz15027) and key project(No.025115033) of the Science and Technology Commission of Shanghai Municipality.
K.-M. Liew et al. (Eds.): PDCAT 2004, LNCS 3320, pp. 545–548, 2004. © Springer-Verlag Berlin Heidelberg 2004
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Information Service in Information Grid
Grid Information Service plays very important role in Grid technique. It provides for locating resources based on the characteristics needed by a job (OS, CPU count, memory, etc.). The Globus Toolkit [3] provides a Monitoring and Discovery Service (MDS)[4] to support development of grid-aware applications which includes Grid Resource Information Service (GRIS), Grid Index Information Service (GIIS) and Information Provider. But for information Grid, it lacks some key features: − QoS Support. MDS adopts a hierarchical structure to collect and aggregate service information. Systems load in high-level information servers will increase violently, and information searching efficiency could not be guaranteed [5]. Moreover, MDS can not provide a reliable index service, for subscriptions are transient in current GT3 implementation. Data loss or inconsistency can occur when the Index Service or any of the aggregated grid service instances are restarted. − Grid-Aware Application Information Support. The information such as workflow, transaction, user information, software licenses must be addressed by Information Service. Fig.1 shows the framework of the Information Service. We define the Information Service Domain (ISD) as a group of services which has same taxonomy, such as booking services domain, financial services domain. Every ISD has one or more Global Information Services (GIS), where all grid resources can deliver their own service data (SD). The resource also stores the information in a Local Information Service (LIS). Service Provider (SP) registers to corresponded LIS. LIS can answer the query of the local information in certain ISD. In Information Grid, a lot of queries are certain Domain-oriented, using LIS will enhance the search efficiency. Each GIS can serve as Yellow Page to provide all the Grid service’s information. Client can use parallel arithmetic to find information from GISs. GIS using GIS-GIS protocol to query or duplicate service information among each GIS. There also exist LIS-GIS protocol, SP-LIS protocol and LIS query protocol in the framework to exchange service information. To achieve the reliable indexing, we use the notification method. Notification is a frequently used software design pattern also known as Observer/Observable. The notification applied in GT3 provides a mechanism which Grid Service can send notification messages to any number of clients. Because the Index Service is also a Grid Service, we can send notification messages between Grid Service and Index Service. When the Grid Service instance starts, it calls Index Service’s add subscription interface to add itself as a new subscription, when the state of the Grid Service Instance has any change, it asks Service Data Element (SDE) to notify Index Service, the Index Service can remove it from the Index. A set of MDS extension is to be developed to address grid-aware application requirements in the framework.
ShanghaiGrid: Towards Building Shared Information Platform Based on Grid
Fig. 1. The framework of Information Service
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Fig. 2. Information Grid Portal
Information Grid Portals
ShanghaiGrid is a platform for varieties Grid Applications such as City Emergency system, intelligent traffic control system, public health management system. The Grid Portal acts as an access point for public user to access Grid Portal like traditional WWW Portal. Currently the existing Grid Portals are mainly Computational Grid Portal which helps to alleviate the complexity of task management through customizable and personalized graphical interfaces for the users (mainly scientists), emphasizes the need for end users to have more domain knowledge than on the specific details of grid resource management such as how to create a job, schedule and monitor its running in distributed resources, get the results and so on. In contrast, the IGP helps the end users (mainly the people without much knowledge about computer science) get the information they want such as long-term weather forecast, traffic information. The Portals in ShanghaiGrid are divided into Global Portal (GP) and Domain Portal (DP). Fig.2 shows the portal model in detail. The transaction support and workflow management are very important for information Grid which could be found in our previous study [6][7].
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Summary
In this paper we introduce our research on the implement of Information Grid. Compared with Computational Grid, Information Grid provides information rather than computational power. So the QoS-aware Information Service and workflow supported Portal are much more important in Information Grid. Our next step is to build a set of Information Grid develop toolkit to facilitate the development of ShanghaiGrid.
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References [1] Minglu Li, ShanghaiGrid in Action: The First Stage Projects towards Digital City and City Grid, GCC 2003. [2] Melissa Hyatt , The information grid, www.ibm.com/ developerworks/ [3] http://www.globus.com [4] Monitoring Discovery Service http://www.globus.org/mds/ [5] Deqing Zou, etc. HH-MDS:A QoS-Aware Domain Divided Information Service GCC 2003. [6] Feilong Tang, Minglu Li, etc.Coordinating Business Transaction for Grid Service. [7] GCC 2003 [8] Jian Cao Minglu Li Shensheng Zhang Qianni Den, Composing Web Services based on Agent and Workflow. GCC2003.
