1. slide 1 Experiences with NMI R2 Grids Software at Michigan Shawn McKee April 8, 2003 Internet2 Spring Meeting

2. slide 2 Outline  Apps tested at Michigan  A little about our environment and motivations  Experiences for each application

3. slide 3 Grid Components Tested at Michigan  Globus  Condor-G  NWS  KX509  GSI OpenSSH  GridConfig

4. slide 4 MGRID – www.mgrid.umich.edu  A center to develop, deploy, and sustain an institutional grid at Michigan  Many groups across the University participate in compute/data/network-intensive research grants – increasingly Grid is the solution ATLAS, NPACI, NEESGrid, Visible Human, NFSv4, NMI  MGRID allows work on common infrastructure instead of custom solutions

5. slide 5 MGRID: Goals  Provide participating units knowledge, support and a framework to deploy Grid technologies  Provide test bench for existing and emerging Grid technologies  Coordinate activities within the national Grid community (GGF, GlobusWorld, …)  Provide a context for the University to invest in computational and other Grid resources

6. slide 6 Tier 1 Tier2 Center Online System Offline Farm, CERN Computer Ctr ~25 TIPS BNL Center France Italy UK Institute Institute ~0.25TIPS Workstations ~100 MBytes/sec 100 - 1000 Mbits/sec Physicists work on analysis “channels” Each institute has ~10 physicists working on one or more channels Physics data cache ~PByte/sec ~2.5 Gbits/sec Tier2 Center ~2.5 Gbps Tier 0 +1 Tier 3 Tier 4 Tier2 Center Tier 2 CERN/Outside Resource Ratio ~1:2 Tier0/(  Tier1)/(  Tier2) ~1:1:1 Data Grids for High Energy Physics

7. slide 7 ATLAS Grid Testbed (US)  10 sites University groups: BU, IU, UM, NM, OU, SMU, UTAUniversity groups: BU, IU, UM, NM, OU, SMU, UTA Labs: ANL, BNL, LBNLLabs: ANL, BNL, LBNL 15-20 users  All sites: Globus & Condor AFS, ATLAS software release Dedicated resources Accounts for most users on all machines  Applications: Monte Carlo production w/ legacy code Athena controlled Monte Carlo

8. slide 8 Globus Experiences  We had already been using Globus since V1.1.3 for our work on the US ATLAS testbed  The NMI release was nice because of the GPT packaging which made installation trivial.  There were some issues with configuration and coexistence: Had to create a separate NMI gatekeeper to not impact our production grid users No major issues found…Globus just worked

9. slide 9 Condor-G  Condor was already in use at our site and in our testbed.  Condor-G installed over existing Condor installations produced some problems: Part of the difficulty was not understanding the details of the difference between Condor and Condor-G A file ($LOG/.schedd_address) was owned by root rather than the condor user and this “broke” Condor-G. Resolved via the testbed support list

10. slide 10 Network Weather Service (NWS)  Installation was trivial via GPT (server/client bundles)  Interesting product for us. We have done significant work with monitoring.  NWS advantages: Easy to automate network testing, once you understand the config details Prediction of future value of resources is fairly unique and potentially useful for grid scheduling  NWS disadvantages: Difficult user interface (relatively obscure syntax to access measured/predicted data)

11. slide 11 KX509  This application was developed at Michigan and was used at a testbed level until recently  Michigan is a Kerberos site  MGRID wants to use KX509 for all “certificates” within campus.  We were unable to get KX509 to work University-wide at Michigan…  Problem was a bad “CREN” root certificate complicated by insufficient error checking/handling in the Globus code.  Should have a “fixed” root certificate shortly…

12. slide 12 GSI OpenSSH  Useful program to extend functionality of PKI to OpenSSH.  Allows “automatic” interactive login to proxy holders based upon Globus mapfile entries  Simple to install---In principle a superset of OpenSSH on the server end  We had a problem with a conflict in dynamic libraries which it installs on a non-NMI host

13. slide 13 GridConfig  We tested GridConfig to determine how useful such a system would be for our needs  General impression was that this is a potentially useful tool.  Would like to see: Improved config checking capability More awareness of application interactions and config dependencies between applications

14. slide 14 Conclusions  Applications were all easy to install via GPT  Configuration details are still not that easy, but tools like GridConfig should help in the long term  We hope to do much more detailed testing with future releases and are already planning to build applications and our environment for MGRID on the NMI release