EGEE is a project funded by the European Union under contract IST-2003-508833

Network monitoring with R-GMA in EDG

Paul Mealor

Researcher

JRA4 R-GMA meeting, 22 July 2004

www.eu-egee.org

JRA4 R-GMA meeting, 22 July 2004 - 2

Contents

• Disclaimer

• Monitoring tools and modifications

• Probes Coordination Protocol

• Network Cost Estimation System

• Schemas

• Related work

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Disclaimer

• R-GMA components have changed a lot since EDG Streaming producer Primary producer (memory) Consumer Consumer Archive, database Well, it’s changed

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Measurementwrapper

script

Monitoring tools and modifications

• PingER (which begat IperfER and UDPMon)

• Wrapper script run periodically By Cron, and latterly PCP

• Runs ping, captures output

• Output stored in flat text files

• Web user interface Displays graphs and tables Also, unformatted data available

Web UI

Text files

Ping

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Measurementwrapper

script

Monitoring tools and modifications

Web UI

Text files

Ping netmon2rgmad

StreamProducer

Servletson

dedicatedmachine

MySQLArchive

Archiver

DBProducer

Consumer

netmonarchiverd

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GridFTP daemon(gsiwuftpd)

Monitoring tools and modifications

• GridFTP daemon

• Can be set to write logs

• ftlog2rgmad reads logs for updates File gets longer: new entries at end File gets shorter: everything’s a new entry

• Publishes new entries via Stream Producer

Log

ftlog2rgmad

StreamProducer

Servletson

dedicatedmachine

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Probes Coordination Protocol

• Full-mesh measurements impossible

• Hand-built, centralised schedules don’t work

• PCP automates scheduling

• Token passed between nodes in a clique

name:iperfmember:ccwp7.in2p3.frmember:adc0003.cern.chmember:grid001f.cnaf.infn.itmember:gppnm.gridpp.rl.ac.ukmember:mon001.fzk.deperiod:1800timeout:600delay:60option:ExternalLockcommand:edg-iperf iperf

• Nodes with the token can make measurements

• Many cliques can coexist Allows hierarchies to be set up ExternalLock option: no other commands while this one is running

edg-pcp-extern-lock program to lock a pair of hosts

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Probes Coordination Protocol (2)

• Fault tolerance Token should traverse the clique in period seconds If it left a node period + timeout seconds previously a new token is

generated• Protects against lost tokens

Duplicate tokens are dropped

• Configuration updates Are easy: the token contains the

configuration

name:iperfmember:ccwp7.in2p3.frmember:adc0003.cern.chmember:grid001f.cnaf.infn.itmember:gppnm.gridpp.rl.ac.ukmember:mon001.fzk.deperiod:1800timeout:600delay:60option:ExternalLockcommand:edg-iperf iperf

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Network Cost Estimation System

• Implemented for C++ and Java

• Multiple backends MySQL R-GMA (ish :-/ ) LDAP

• Extra information: Mapping tables: NetworkCE and NetworkSE Match all SE/CEs to a Network Monitor

NetworkCost getNetworkCost(source,dest,filesize)

NetworkCost[][] getNetworkCosts(sources[],dests[],filesize)

netmon-rgma-info

StreamProducer

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Network Cost Estimation System

• To be done: Make use of the GridFTP data Actually use R-GMA to query the Archive

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Schemas

NetworkTCPThroughputNMIdSourceNMIdDestinationtoolbufferSizestreamsdurationtimevalue

NetworkCE

CEIdNMId

NetworkRTT

NMIdSourceNMIdDestinationtoolpacketSizetimeminimummaximumaverage

NetworkCE

CEIdNMId

NetworkSE

SEIdNMId

ComputingElement

CEIdGRAMVersionArchitectureOpSys&c…

1

1

1

1

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Related work

• Glue Schema Almost identical schemas (as they were based on ours) Measurements associated with a “Network Element” Network Element is a path between two nodes, with a particular

QoS and so on

• NMWG How do these XML schemas translate?

• In WP7 MapCenter (visualisation of host status) TopoGrid (visualisation of paths)

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END

• http://www.hep.ucl.ac.uk/~pdm/edg/docs/

• EDG WP7: http://ccwp7.in2p3.fr/

• PCP/GNMA: see WP7 final deliverables