The Grid computing

Presented by:-Mohamad Shalaby

What is Grid Computing?

Computational Grid is a collection of distributed, possibly heterogeneous resources which can be used as an ensemble to execute large-scale applications. Computational Grid also called metacomputer

The difference between Grid Computing and Cluster Computing• Cluster computing: focuses on platforms consisting

of often homogeneous interconnected nodes in a single administrative domain.

• Clusters often consist of PCs or workstations and relatively fast networks.

• Application focus is on cycle-stealing computations, high-throughput computations and distributed computations.

• Grid: focus on ensembles of distributed heterogeneous resources used as a platform for high performance computing.

some grid resources may be shared, other may be dedicated or reserved.Application focus is on high-performance, resource-intensive applications.

the grid is a net bound system that needs efficient and reliable communication and high performance browsers with high level security performance

the grid is bound to efficient matching algorithms for: user-certificate match job-resource match master data objects, subset and replicas identification.

the grid depends on accurate clock performances to synchronize nodes and correctly handle task and job scheduling

How to use the grid?

To use the grid we need to use a Grid Middleware ‘graphical user interface (GUI)’ or ‘command-line interface (CLI)’

Grid middleware: is built by layered interacting

packages and may be tailored using different managers so that the users are not concerned of the different syntax and access methods of specific packages. Our used middleware was PUTTY software.

PuTTY: PuTTY is a client program for the SSH, Telnet and Rlogin network protocols. These protocols are all used to run a remote session on a computer, over a network. PuTTY implements the client end of that session: the end at which the session is displayed, rather than the end at which it runs.One can download this software from:

http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

Data management: -Initialize your proxy-certificate

$ voms-proxy-init -voms edu

list all files and directories$ lfc-ls /grid/edu

-Creating and editing files on the user interface $ vi <filename>

-To write in this file press i and start writing

to stop editing press ctrl + cto save the file press shift + :to exit from the file press wq the enter

-To get full information about privileges and access$ lfc-getacl /grid/edu

-To create directory at LFC$ lfc-mkdir /grid/edu/<your dir>

-To submit a job on the grid $ lcg-cp -v lfn:/grid/edu/<path to file> file:/home/<path to file>

Example$ lcg-cp -v lfn:/grid/edu/alla/test3.lfn file:/home/zmey/test3.dat

-To check the status of the job$ glite-wms-job-status -i job.id

-To get the out put of the job $ glite-wms-job-output --dir result -i job.id

-To upload files in grid

$ lcg-cr --vo edu file:<path to your file> -l lfn:/grid/edu/<your dir>/<name of the file>.lfn

Example

-To transfer the output from grid to GUI$ lcg-cr --vo edu lfn:/grid/edu/<your dir>/<name of

the file>.lfn -l file:<path to your file>

-To transfer the output from user interface to your local machine we used a software called WinSCP.

VBrowser

VBrowser is intended as single frontend to the Grid for data management.

It was developed by Piter T. de Boer from the University of Amsterdam.

It supports core grid file systems like Grid-FTP, SSH-FTP, SRM, LFC and SRB out of the box and present them to the user in an easy to use tree like structure.Since it is written in Java no additional (grid) software is needed and it can be easy downloaded and deployed on any modern computer or laptop supporting Java 1.6 (or higher).

Main Features : * All Grid resources logically ordered in an explore-like browser using "Resource Folders". * Easy to use 'drag and drop' interface to do file management. * Single sign-on authentication to all (remote) Grid resources using Grid proxy authentication. * Multi client framework suitable for accessing: plain web services, OGSA Grid Services, both Globus 4.0 and Globus 4.1 Grid Services.

Architecture: VBrowser Design Overview

How to use it?VBrowser: Resource Overview

V-Browser: Authentication