If you are ready, let's start!
openssl pkcs12 -in export.p12 -clcerts -nokeys -out $HOME/.globus/usercert.pem openssl pkcs12 -in export.p12 -nocerts -out $HOME/.globus/userkey.pem
The user certificate can safely be world readable, but userkey.pem must only be readable by you!
chmod 0400 $HOME/.globus/userkey.pem
The type of program we will be running can be called bag-of-tasks or BoT for short.
Your (very simple) program, preferably written in C, should implement a loop with a variable number of iterations. The output of the program will be the number of iterations performed added by some text. The number of iterations should be given to the program in the command line.
Compile your program. Test it in the glite-tutor machine.
Write a JDL description that you can use to submit your program to run in the grid.
Try submitting 10, 100 and 500 jobs to gLite with the same number of iterations and observe the time taken to complete all jobs (makespan).
For help with the commands visit the GILDA wiki training material web page and follow the "Basic" exercises or visit the gLite documentation page