Recommendations Concerning This Exercise

The Visualization Tool produces numerous graphs and can generate a large amount of X activity over the network. If you notice that your terminal's response is getting slower, it might be best to wait a little while a try VT again later when fewer people are doing this exercise.

1. Set Your Workstation's xhost Permissions

   Open a new window on your workstation and enter the command "xhost +" to permit the SP machine to send X displays to your local workstation.

2. Login To The SP Machine

   Make sure that you are logged into your assigned SP node with your assigned userid for this exercise. Ask the instructor if you have any questions.

3. Set the DISPLAY Environment Variable

   After logging into the SP, specify that X clients should be displayed on your workstation by using one of the commands below. Note that you should substitute the real IP address or machine name of your workstation for "machine.address". Ask your instructor if you have any questions.

   csh/tcsh	setenv DISPLAY machine.address:0
   bsh/ksh	export DISPLAY=machine.address:0

4. Verify The Environment Variable $WORKSHOP

   The $WORKSHOP variable defines the root location for the workshop files, and may vary from workshop to workshop. Find out if this has already been setup for your workshop:

   echo $WORKSHOP

   If this environment variable is not set, check with the instructor for the correct location. Then, depending upon your shell, set $WORKSHOP:

   csh/tcsh	setenv WORKSHOP instructor/specified/path
   bsh/ksh	export WORKSHOP=instructor/specified/path

5. Copy An Example Trace File

   In your SP home directory, create a subdirectory for the VT exercise code, cd to it, and then copy the VT exercise file there.

   mkdir vt
   cd vt
   cp $WORKSHOP/vt/samples/* .

6. Start VT Using An Example Trace File

   The trace file being used was created from the 2D-FFT MPI lab exercise. Start VT using this trace file with the following command:

   vt -cmap -tracefile mpi_2dfft.trc &

   After a few moments, the two initial VT windows will appear. Notice that a trace file will automatically be loaded by VT. Note: the -cmap argument allows VT to start with its own colormap, thus avoiding problems with other X Windows applications (such as a web browser) which are using colors needed by VT.

7. Trace Analysis

   1. Select several different views from the VT view selector window. When you are ready, begin playback of the demonstration trace file.

   2. Try stopping, restarting, and looping the trace file playback.

   3. Use the mouse to display additional information for any point on any of your views (left button).

   4. Use the mouse to modify a view's confiuration options and/or view parameters (right button).

   5. Try different views, especially for Communications. Also, please do not open more than 5 or 6 views at any one time if there are several other people doing the exercise at the same time as you.

   6. If you are interested, try saving your customized view arrangements. Then, load your VT config file and observe how VT will preserve your favorite settings.

8. Performance Monitoring

   1. From a main VT window, select the Performance Monitor from the pull down menu. Note that you may first wish to close the VT view selector window because the Performance Monitor will open a very similiar window. This simply helps to avoid confusion.

   2. After selecting Performance Monitor, two new windows will appear: The Performance Monitor and the Performance Monitor View Selector windows.

   3. Choose several nodes to monitor. Then select several views. When you are ready to begin, select "Toggle Monitoring" from the Performance Monitor window.

   4. After a few seconds, you should begin to notice real time monitoring of the system activity. Note: unless there are jobs running on the system, you will not notice much activity. If this is the case, you can start up a program and then watch its effects via the performance monitor. The MPI Prime Number Generation example code might be a good choice for a job to run while monitoring, as it will run for more than a few seconds.

   5. Use your mouse to obtain additional information about any point in any view.

   6. Try several different views. Again, please limit the number of open views to 5 or 6.

   7. Change the Performance Monitor sampling interval. Try 3 seconds instead of the default 10 seconds.

9. Trace Record Generation

   If time permits and you are interested, try creating your own trace file from one of the MPI example codes and then viewing it. The instructions, How to Generate Trace Files in the VT tutorial describe how to do this.

10. Shutdown

    When you are finished, close all VT windows and logout of the SP machine.

This concludes the VT exercise.