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Experiences with NMI R2 Grids Software at Michigan

Shawn McKeeApril 8, 2003

Internet2 Spring Meeting

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Outline

Apps tested at Michigan A little about our environment and

motivations Experiences for each application

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Grid Components Tested at Michigan

Globus Condor-G NWS KX509 GSI OpenSSH GridConfig

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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

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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

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Tier 1

Tier2 Center

Online SystemOffline Farm,

CERN Computer Ctr ~25 TIPS

BNL CenterFrance ItalyUK

InstituteInstituteInstituteInstitute ~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 CenterTier2 CenterTier2 Center

~2.5 Gbps

Tier 0 +1

Tier 3

Tier 4

Tier2 Center Tier 2

CERN/Outside Resource Ratio ~1:2Tier0/( Tier1)/( Tier2) ~1:1:1

Data Grids for High Energy Physics

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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

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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

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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

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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)

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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…

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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

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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

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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