Grid Computing

Grid computing is a kind of distributed system, includes the network infrastructure and software framework, and provides computing services by the distributed hardware and the software. The goals of the Grid computing are improving computer power capacity, resource utilization, and access resource by connecting the large number distributed resource from geographically or the organization. In addition, The Grid system allows the VOs all over the world to sharing the resources each other and satisfies the large computing requirements of the user.

Different organizations share resources or cooperate together for the same goal. These organizations are called VO in the Grid system. The resource, not only means the computer, application service provider, hardware or network resource, but also including the software, scientific instrument and commercial information. In the Grid environment, every VO attaches great importance to mutual trust, communication and coordination. Toward with the available resources, VO also provides the application protocols and the structures for the member who owns the access right [46].

In 2004, European Union expanded the Grid application environment and established the EGEE (Enabling Grids for E-Science and Industry in Europe) planed to expand e-Science research, education and industrial application. In United States, established the Grid3 plan according with the LCG [31] development experience, and to promote Open Science Grid.

Expect that Grid will become the important assistance in the scientific research, education and social changes. Due to these organizations collaboration are promoting the Grid scientific development. Taiwan is also committed into the Grid research, the apparatus of government and schools build the Grid systems environment together, and research in the new theory and technology. The Tunghai University presented the TIGER Grid project [49]. There are

many high schools and universities joined this project from the central of Taiwan. In 2006, Taiwan UniGrid project [50] attracted more than 30 schools, and coordination with Academia Sinica, and National Center for High-Performance Computing. At present, the Grid applications have practical in various fields such as medicine simulation, medical and high-energy physics.

Figure 2-1 Commercial Grid solutions taxonomy [38]

Grid computing is not only practiced in the science experiment, Figure 2-1 shown the development of computing technologies in recent years, from the beginning of the cluster computing to the current open standards Grid environment can be seen Grid computing has increase the scope in variety of commercial applications gradually. The powerful computing capacity let researchers devote to the meteorological models or weapon simulations.

Meanwhile, Grid computing is diffusing to traditional business computing applications show as Table 2-1. Following IBM presented eBoD in 2002, Amazon began selling Elastic Compute Cloud (EC2) [1] services on the internet in 2006. EC2 provided on demand and flexibility calculation services by web service, and mainly to help developers use the wider

Open Grids

computing resources more easily. In 2007, SUN also launched the On-Demand Computing [47] services, and determines the price by the rental of CPU or the cost of time, and customers can accordance with their requirements buy CPU computing resources. Above On-Demand Computing also represents the development of Grid computing, and become more close to people's lives.

Table 2-1 The Grid computing applied to enterprises or products in recent years.

Time Name Company The Goal

2002 PLM (Product Life Management) SUN PLM import manufacturing processes to enable enterprises have lower costs for integrate existing IT resources, such as processing power, storage devices, memory and network bandwidth. Enterprises not only allow users to allocate network resources flexible, but also implementation on compute-intensive application.

2004 World Community Grid

[http://www.worldcommunityGrid.org/]

IBM In this plan, the researchers use the information technologies study in the

"World Community Grid", and analyze the large number of cancer tissue microarray (TMAs, tissue microarrays) for process number of experiments in the short time.

2004 Oracle 10g Oracle Oracle Grid adopts server and the modular storage equipment which with lower cost, make the efficient load balance of system. The user can enjoy the high-performance and reliability with the lowest overall cost of information services. The current version is Oracle 11g.

2007 HYDRAstor

[http://www.necam.com/Storage/GridStorage.cfm]

NEC HYDRAstor uses Grid-base storage technology, and is developed by U.S.

NEC Laboratories America Inc. It is according to the NEC’s server and the storage experience of business, each unit cost of storage will be reduced to one-tenth of the past similar products.

In August 2006, the U.S. Oracle in Asia-Pacific (APAC) published, according to the Overall Grid Index report that the Grid applications use in business organizations in APAC grow faster than other regions of the world. This report also indicated that the amount of business organizations in Asia-Pacific who has, or plan to establish Grid computing system increased 83 percent than in 2005 (compare with the lower growth in the United States 45 percent and Europe 7 percent ). Meanwhile, the awareness and understanding of basis Gird capacity in Southeast Asia is top three of the world. The Quocirca research director Clive Longbotom expressed his view for the Asia-Pacific region, he said that the utilization of Grid computing increased in Asia-Pacific region from the Grid computing bring the business organizations a new value and attention. The above describes show Grid computing operates in the enterprises or the acceptances of the Gird are both growing positively [37].

Grid middleware is used to integrate the scattered computing resources, and responsible for the coordination functions between the computing nodes. One of the important components in the Grid middleware is metadata. The European Data Grid project, that is cooperated from 150 software engineers and complete over 300,000 lines of code. In short speaking, the main purpose of the Grid middleware is to achieve resource sharing, security access and the resource management. There are some common Grid middleware, such as Globus Toolkit, China Grid Support Platform [4], gLite [13], and UNICORE [52], and the so on. Globus Toolkit is the most popular Grid middleware, and proposed many Grid-related standards. In 2001, Department of Institute of Physics in Academia Sinica participated in the LCG project (Worldwide LHC Computing Grid) [31] of European Organization for Nuclear Research (CERN). The core middleware of LCG is gLite, and gLite adopt some part components from the Globus Toolkit, with various packages developed from its own team.

In addition to the Grid middleware and the application development, many Grid-related studies researched in the job scheduling, load balancing, data management and security issues.

In the traditional job scheduling and load balancing studies considered less on the heterogeneity significant of the Grid system or the experimental methods were not suitable for the heterogeneity Grid system. In recent years studies, consider the heterogeneity characteristics of the Grid system gradually, including the computing ability, bandwidth and distance. In [42] study, adopted job arrival rates and the job response time for load balancing factors. In [34, 33] studies, authors collected job total response time for the assessment standard, and to group the computing nodes who have powerful computing ability, the job will be assigned priority to these group. In [54], author considered of the user's expect deadline and the migration cost of job. Above studies almost implemented experiment and presented the experimental results by the simulation, also show that it is hard to experiment with real Grid system.

2.1.1 Globus Toolkit

Globus provides a framework for application to process distributed heterogeneous computing resources. The Globus project developed by Globus Alliance [65] which members including Argonne National Laboratory and University of Southern California, and these members devote to the computing environment development. IBM, INTEL, HP, SUN and other enterprises are also support to Globus Toolkit.

The process of Grid technology development, while not long, but the core technology is already has great progress. Currently, the most of gird projects are established by the Globus Toolkit protocols and services, shown as Figure 2-2. Globus Toolkit is an open-source and free for users, and can be modified by users demand. The object-oriented structure of Globus Toolkit provide many services, including the resource monitor, resource discovery, execution management, security infrastructure and data management. The programmer can adopt suitable tools from above services and integrate with existing software for Grid system

deployment. That is why Globus Toolkit so popular in the Gird system construction. The latest open version is Globus Toolkit 5.3.

Figure 2-2 Globus Toolkit 4 Services

Globus Toolkit provides the following functions:

„ Security

The security service in Globus Toolkit provides users authentication identifies, protection communication channel, and to determine who was allowed to perform actions (authorization) and other support functions, such as management the user account and maintenance member’s data.

„ Data Management

The data management service in Globus Toolkit achieves to distribute the location, transfer, access and management for the data. GridFTP is a safety, reliable, and high performance transfer protocol, and it apply optimization for data transfer between nodes. The functions provide in GridFTP are parallel transfer, reliable transfer, and support transfer security and

Security

Grid FTP Reliable file

Transfer

integrity for GSI.

„ Information Services

Monitoring and Discovery System (MDS) provide information services components in the Globus Toolkit, including the available information and state in the Grid system. For example, the discovery service can find the suitable node which has better computing resource for the job.

„ Execution Management

Grid Resource Allocation Management (GRAM)

GRAM is the important component for execution management services in Globus Toolkit, its help the user to locate, submit, monitor and remote execution in the Grid system. GRAM is not a task scheduler, but it communicates with the different bath or cluster task scheduler by use the single protocol.

„ Common Runtime Components

After Globus Toolkit version 4, the development team added the common runtime components, pre-web libraries and tools. These services to be platform independent, and establish various abstraction layer and leverage functionality lower in the web service stack.

2.1.2 Condor [6]

Condor is a kind of workload management system for the compute-intensive job. The goals of Condor project is to integrate the large-scale distributed computing resources, and also support implementation, deployment, assessment mechanisms, and adjustment strategies for high-throughput computing. Condor provides a job queue mechanism, scheduling policy, priority scheme, resource monitoring, and resource management. When the user submit their job to condor, condor will place the job in the job queue, then through the adjustment

execution finish, user will be notified. The job types of condor can be supported, including the parallel application(MPI application)、JAVA application、DAGMan application and virtual machine application, the execution state can be classified into run, held and idle, and so on.

The important features in Condor, such as the check point, remote execution, and support the heterogeneity environment [6]。The other developments of Condor, the Japanese scholar Hidemoto Nakada who servers in Department of Grid Technology Research Center in National Institute of Advanced Industrial Science and Technology, developed an application can control condor job queue is called “Condor Java API”, to help the user delivery their job, and cancel the job quickly. Depend on this, developer can control job state more easily, and to extend more application for the Grid computing development [5].