Group 1 : Grid ComputingLaboratory of Information Technology

Supervisors: Alexander Ujhinsky Nikolay Kutovskiy

OutlineWhy using Grid Computing?Practice DescriptionPre-requisites.Procedures

Login to UICreating Required FilesSubmitting JobChecking the Job StatesRetrieving the Output Files

Why Grid Computing?• Reduction in the calculation time

• Reduction in costs

• Reliable and secure data management

• Effective usage of the hardware and software

• Ability to use scalable computer resources

• Ability to integrate and use distributed resources of

organization

Practice DescriptionGiven: movie file (*.avi). It's placed in the grid on the following

path: guid:3f706ca8-fcd3-46fd-a8f4-e3525fcec7db lfn:/grid/edu/course/movie.lfn

Required:Write a script to do the following:

upload the file to the appropriate working nod convert the movie using ffmpeg utility (use flags in

Requirements to find the appropriate host) save converted file to a Storage Element and submit it to the

grid.

Pre-requisites:Should have a valid personal digital certificate (it is a long

lived certificate identifying individuals like passport and commonly used between web browsers to authenticate sites).

Should be registered with at least one virtual organization (edu in our case).

Should have an account on the grid user interface (vps101.jinr.ru).

Should have a SSH client to access the grid UI (Putty Tool).should have a valid proxy certificate(It is a short lived certificate to reduce the vulnerability and

can act on the user’s behalf).

Procedures:1. Login to the grid UIThis is done by using the Putty tool

vps101.jinr.ru

Then you will be asked for your account information as Username and Password.

You can check the existence of a valid proxy certificate

Through the UI, Now I can:

Interact with the data management facilities

Submit jobs

Check Job States Retrieve the output of the jobs

Cancel jobs

2. Creating shell and JDL FilesTo create a shell fileType vi file_name.sh in Putty command

window vi video.sh

lcg-cp -v lfn:/grid/edu/course/movie.lfn file:movie.avi ffmpeg -i movie.avi -ar 22050 c_movie.flv lcg-cr --vo edu file:c_movie.flv -l lfn:/grid/edu/myehia/c_movie_V2.lfn

This command copies the movie file from the grid to the UI

This command uses ffmpeg tool to convert the video file from avi format to flv format.This command saves the new video file to the grid.

Then create a JDL file by using the same command

vi video.jdl

Type = "job";JobType = "Normal";Executable = "video.sh";Environment = {"LFC_HOST=vps104.jinr.ru"};StdOutput = "video.out";StdError = "video.err";OutputSandbox = {"video.out","video.err"}; InputSandbox = {"video.sh"};Requirements = Member("ffmpeg",other.GlueHostApplicationSoftwareRunTimeEnvironment); 

Type of the request described by the JDLThe type of the job described by the JDL.The file to be executed

The environment which is needed by the job to run properlyIt represents the job requirements on resources.The file name where the standard output of the job is saved.The file name where the standard error of the job is saved.List of strings identifying the list of files generated by the job on the WN, which have to be retrievedList of strings identifying the list of files on the UI local disk needed by the job for running and hence needed to be transferred from the UI to the CE.

3. Submitting the JobThis can be done by using the command:

After Submitting the Job Successfully

4. Checking Job State

4. Retrieving Output FilesOnce the job is terminated successfully with exit code = 0, you can retrieve the output files

by using the following command:

Reading output files

The Difference Between the Original Movie File and the New One.

AcknowledgmentThanks to:

Alexander Uzhinskiy

Nikolay Kutovskiy

For their Great Effort and Help During the Last Three

Weeks

Thanks to JINR Staff for their Care.

Thank You All