Using the Grid/Credential delegation

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Credential delegation

  • Problem: Before job submission you may want to delegate your credentials to the Workload Management System (WMS). This can speed up multiple job submissions, but more importantly, when the Grid is busy or when you submit a large number of jobs, it can take more then the standard 12 hours that your proxy certificate is valid for the jobs to start. In that case your proxy certificate expired and the jobs will fail.
  • Solution: use glite-wms-job-delegate-proxy -d <delegation id>.
  • Use: Before submitting jobs to the grid

When you submit a job to the grid it will be send to the Workload Management System (WMS). This system will then schedule your job and send it to a Worker Node somewhere on the grid. The job will be run on your behalf, therefore you should delegate your credentials to the WMS. You only have to do this once per session. When you renew your proxy certificate (by typing voms-proxy-init) you have to delegate it to the WMS once more.

We assume that you have used the voms-proxy-init command and have a valid proxy credential. If not, please see voms-proxy-init.

Use the following command

glite-wms-job-delegate-proxy -d <delegation id>

The variable delegation id is just a string to label the delegation (in this case the your login name from the system). This string is needed in later commands to identify your session. You can use any string you like after the -d option.

Instead of creating a delegation ID with -d, the -a option can be used. This causes a delegated proxy to be established automatically. In this case you do not need to remember a delegation identifier. However, repeated use of this option is not recommended, since it delegates a new proxy each time the commands are issued. Delegation is a time-consuming operation, so it's better to use glite-wms-job-delegate-proxy and reuse the delegation ID when submitting your jobs.

Let's create a delegation ID using the WMProxy by creating a delegation identifier using your username. To get the username we take the $USER environment variable. Remember that you can use any string you like as a delegation identifier.

$ echo $USER

$ glite-wms-job-delegate-proxy -d $USER

Connecting to the service

================== glite-wms-job-delegate-proxy Success ==================

Your proxy has been successfully delegated to the WMProxy:

with the delegation identifier: mgjansen


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