1. CHEP 2003Stefan Stonjek1 Physics with SAM-Grid Stefan Stonjek University of Oxford CHEP 2003 25 th March 2003 San Diego

2. CHEP 2003Stefan Stonjek2 Outline Components of SAM Grid Job submission Example Problems Outlook Summary

3. CHEP 2003Stefan Stonjek3 Components of SAM-Grid (global) JIM (Job and Information Management system) –Frontend and glue Condor-G for global submission and brokering GRAM protocol to transfer job to execution site Authentication via GSI (Grid Security Infrastructure)

4. CHEP 2003Stefan Stonjek4 Components of SAM-Grid (local) Data handling with SAM (Sequential data Access via Meta-data) Local job submission to –CDF: CAF (Central Analysis Facility) FBS: Farm batch system Kerberized tools to write data back to FNAL –DØ: OpenPBS Output data handling via SAM

5. CHEP 2003Stefan Stonjek5 Submission to the Grid User must provide : –Grid proxy –Job description file –“tar” file with executable and configuration files GUI exists (generates “jdf” file, “tar” file and submits) Submission to via JIM to Condor Submit to the site with the most files of the required dataset already present –New Condor-MMS feature: execution of external code when negotiating the matches –Here: calls SAM to check for the presence of input data at different locations

6. CHEP 2003Stefan Stonjek6 Local Submission Job is transferred as “tar” file via the GRAM protocol and than submitted to the local batch system Different local batch systems are possible –Need adaptor for submission and job status information –Supported at the moment: FBS, PBS, LSF, Condor Queues have to be the same at all sites –Problem: job should not stop in the middle of an input file –User has to limit amount of input relative to CPU time in queue (needs to know queue CPU time) or provide CPU time per event (difficult)

7. CHEP 2003Stefan Stonjek7 SAM-Grid Architecture

8. CHEP 2003Stefan Stonjek8 Job Description File executable =./run-job.sh sam_dataset = jbot0g input_sandbox_tgz = inbox.tgz output_sandbox = sam@sam.fnal.gov:/www/output.tgz email = stonjek@fnal.gov job_type = caf caf_job_type = sam caf_initial_section = 1 caf_final_section = 1

9. CHEP 2003Stefan Stonjek9 Data Handling (SAM) If needed SAM transfers the files to the local site SAM translates dataset name to list of files Selection can be based on physics meta- data File transfer and delivery is transparent for the user

10. CHEP 2003Stefan Stonjek10 Job Monitoring Monitoring via a Web page Job is identified by a global job ID Decentralized approach –Several independent web-servers possible

11. CHEP 2003Stefan Stonjek11 Layout of the Example (shown at Supercomputing 2002, November 2002) Submission via command line Broker to one site Transfer via GRAM protocol Local job submission by CAF Job monitoring via Web Transfer of results via kerberized rcp to FNAL web server

12. CHEP 2003Stefan Stonjek12 Grid Map CDF – Kyungpook National University, Korea – Rutgers State University, New Jersey, US – Rutherford Appelton Laboratory, UK – Texas Tech, Texas, US – University of Toronto, Canada DØ – Imperial College, London, UK – Michigan State University, Michigan, US – University of Michigan, Michigan, US – University of Texas at Arlington, Texas, US

13. CHEP 2003Stefan Stonjek13 Physics Standard CDF analysis job submitted via SAM-Grid and executed somewhere z0(µ 1 )z0(µ 2 ) J/ψ => µ + µ -

14. CHEP 2003Stefan Stonjek14 Problems (Security) Firewalls (different settings at different sites) –Block all incoming connection to unpriviled ports –Cancel idle TCP/IP connection –Communication problems, in particular for remote execution Authentication (ssh, kerberos, GSI,...) –FNAL allows just kerberized access Different and local policies Problem: How to write back the data? Grid Security Infrastructure (GSI) might help

15. CHEP 2003Stefan Stonjek15 Problems (Private Networks) Already problems with SAM Worker node can contact outside world Outside world can not call back Problem if long time between call from worker and the response from the outside IPv6 might be a solution

16. CHEP 2003Stefan Stonjek16 Outlook Deploy SAM-Grid to further locations Develop SAM-Grid towards production readiness

17. CHEP 2003Stefan Stonjek17 Summary Several new tools and protocols were used to from a Grid enabled environment to do physics SAM-Grid is able to use Grid technology to perform real world physics analysis

18. CHEP 2003Stefan Stonjek18