P-GRADE Grid Portal is an open source workflow-oriented Grid portal that enables the development, execution and monitoring of workflows composed of sequential jobs, parallel jobs and application services. The P-GRADE Portal can be used to develop and execute workflow applications on Grid systems built with Globus, EGEE (LCG or gLite) and ARC middleware technologies. The aim of this tutorial is to demonstrate the EGEE capabilities of the P-GRADE Portal using the GILDA training infrastructure.

The tutorial covers the following P-GRADE Portal features:

• Managing user certificates
• Importing workflows
• Developing, executing and monitoring workflows
• Using Storage Elements

1. Open the URL: http://portal.p-grade.hu/multi-grid
   
   
2. Login to the P-GRADE Portal using the account which was given to you by the tutor.
3. Set notification information: P-GRADE Portal is able to notify the user in email about state changes of the grid application. To enable this feature please click on the “Workflow” portlet, then on the “Notify” sub-portlet. Set
   
   Email settings:
   
   • Enabled: Yes
   • Email address: Specify your email address
   • Email subject: P-GRADE Portal workflow status change
   
   Workflow Change Settings:
   • Enabled: Yes
   • Message: Specify a message content using the listed keys as macros to be automatically replaced by actual values
   An example setting is shown on the screenshot:

1. Download the archive file of the traffic simulation workflow onto your desktop computer. The archive file can be found here.
   
   
2. Go back to the portal and click on the "Upload" submenu of the "Workflow" tab
   
   
3. Select the previously downloaded archive file using the "Browse" button and click OK
   
   
4. Click on the "Workflow manager" submenu of the "Workflow" tab
   
   
5. Click on the "Workflow editor" button and open the previously imported workflow ("Open" item in the Workflow menu)
   
   
6. Check the mapping of the jobs. All of them should be allocated to "gilda_GLITE_BROKER" grid. ("Workflow properties" item in the "Workflow" menu)
   
   
7. Save the workflow ("Save" or "Save as" in the "Workflow" menu)

1. Open on the "Certificates" tab
   
   
2. Click on the "Download" button
   
   
3. Submit the download form with the following values:
   • Hostname: grid001.ct.infn.it or n40.hpcc.sztaki.hu
   • Port: 7512
   • Login: parisXX
   • Password: parisXX
   • Lifetime: 24
   • Description: optional
   
   
4. If download is successful then set your proxy for the "gilda_GLITE_BROKER" Grid

1. Go back to the Web interface of the portal and click on the "Refresh" button on the "Workflow" tab
   
   
2. Click on the "Submit" button of the workflow
   
   
3. The notification engine asks if you wish to get informed in email about status changes. Select "ON ANY STATUS CHANGE" or "ON WORKFLOW END ONLY"
   
   
4. Monitor the progress of the workflow from the Workflow Editor and using the "Workflow portlet" (Click on "Details" then on "Visualize")

1. Open a new workflow (Workflow menu in the Editor) and define a new job with the following parameters:
   • Name: Multiplication
   • Job type: SEQ
   • Job executable: local path of the previously downloaded matrix_operations file
   • Attributes: M V
   • Grid: gilda_GLITE_BROKER
   
   
   
2. Define a port for the job with the following parameters:
   • Port Name: 0
   • Type: In
   • File type: Local
   • File: local path of the previously downloaded INPUT1 file
   • Internal File Name (case sensitive): INPUT1
   
   
   
3. Define a second port to the job with the following parameters
   • Port Name: 1
   • Type: In
   • File type: Local
   • File: local path of the previously downloaded INPUT2 file
   • Internal File Name (case sensitive): INPUT2
   
   
   
4. Define a third port to the job with the following parameters:
   • Port Name: 2
   • Type: Out
   • File type: Local
   • Internal File Name (case sensitive): OUTPUT
   • File storage type: Permanent
   
   
   
5. Save your workflow as Multiply, go back to the browser, click "Refresh" then "Submit" on the "Workflow manager" panel.
   
   
6. Monitor the execution from the workflow editor and from the browser
   
   
7. After the workflow reached fininshed state download and unzip its result file.

1. Save the Multiply workflow as Multiply_remoteout ("Save as" in the "Workflow" menu)
   
   
2. Modify port 2 to a remote file:
   • Double click on port 2
   • Set the "File type" parameter to Remote
   • Set the "File" field to lfn:/grid/gilda/tutorials/parisXX/multiply_output
     (XX refers to your ID on the t-infrastructure)
   
   
3. Save your workflow.
   
   
4. Submit your workflow and monitor its execution from the workflow editor and from the browser.
   
   
5. Please note that after the execution there is no result file to download!.
   
   
6. Check the existence of the result Grid file from the File Management portlet:
   
   
   • Open the File Management portlet
   • Set Select Grid listbox to gilda, then click on View in the same line
   • Set Select VO listbox to gilda, then click on View in the same line
   • Select lfc-gilda.ct.infn.it LFC host and click on List
   
   Be patient and then navigate into /grid/gilda/tutorials/parisXX directory using the "File Browser" and the "Change Directory" buttons.
   Download the matrix_output file to your desktop and check its content. It should be the same as earlier when local output file were used.
   
   

• Multip: A*B   (command line parameter: M)
• Column0: A*B[*, 0]   (command line parameters: C 0)
• Column1: A*B[*, 1]   (command line parameters: C 1)
• Transpose: A*B[*, 0]^T   (command line parameter: T)
• Multip.2: A*B[*, 0]^T * A*B[*, 1]   (command line parameter: M)

Figure 1: Matrix workflow to compute AB[*, 0]^T * AB[*, 1]

EGEE-II is a project funded by the European Union under contract number INFSO-RI-031688