Maximizing Data Transfer Efficiency in Grid Computing Systems
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Explore data transfer efficiency in grids, infrastructure optimization, proactive approaches, and interoperation standards for robust performance. Address challenges, best practices, and evolving strategies for enhanced computational outcomes.
Maximizing Data Transfer Efficiency in Grid Computing Systems
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Presentation Transcript
Data Transfer Efficiency- leave no byte unchurned Jens Jensen Rutherford Appleton Laboratory GridPP26, U Sussex, March 2011
Background • GridPP’sdata grid • Distributed Storage Elements • Data movers (FTS, PhEDExet al) • Catalogues (usu. replica) • e-Infrastructure (aka cyberinfrastructure) • (Presentation at ISGC)
The Data Grid • WLCG is primarily a data grid • Computation can (in principle) be redone • Jobs go to where data is • Moving a job is quicker than moving data
Postmature non-optimisation is the root of some evil • The role of infrastructure code • Scientist as a programmer • “Bad” code moves up the stack? • “Bad” code improves over time? • Doofers stay in prod’n
Efficiencaciousness Goals Service • Availability • Performance • Grows as needed • Robust (no SPoF?) People • (Effective) support • Training • Expertise • Availability of…
Approaches • Philosophy • Get it done – WLCG • Get it done right – EGI? • Do It Perfectly The First Time… • Evolutionary (control system) vs revolutionary • Proactive vs reactive
Efficiencaciousness Issues • Failures • Sites – BDII, network • Elements – storage • Components – disk servers • Timeouts • DDoS
Efficiencaciousness Issues • Overall effort • Funded, contributed, external • Availability of expertise • Single Point of Knowledge • Decoherence • 2nd Law of Thermodynamics • Learning from incidents
Efficiencaciousness Issues • Primary communication • Sites • Users: large VOs, small VOs, single users • PMB • Secondary • WLCG • NGS
Efficiencaciousness Issues • Sites • There Is Always A Bottleneck Somewhere • Site dependent • Usage dependent • Information • Freshness • Accuracy (“spped is substutefoaccurcy”)
Efficiencaciousness Issues • Usage patterns • C.f. Wahid’s talk yesterday • WAN vs LAN (WN) traffic • Technology • In the narrow sense (drives, controllers) • And the wider sense: dist’dfilesystems • Support: Upstream (EGI), Fabric
Efficiencaciousness Issues • Overheads • Complexity of use of stack (see next) • Infrastructure is complex • But Complexity Has To Go Somewhere • Time-to-production • Testing, troubleshooting, monitoring, tweaking, tuning
Particular Pain Point Principle Progress
Progressing Forward • What is progress • How to measure progress
The Good News • We’ve come a long way • Don’t think there is a skills gap • But some SPoKs
Graeme’s talk • “Get the best out of what we can afford to buy” • Proactive sites better • Standards are good
E[GM]I involvement • EMI data roadmap • Support for dCache, DPM, StoRM • Support for standards (NFS4, CDMI) • But then • StoRM=INFN, dCache=DESY, DPM=CERN
The Cloud View • Supplement resources with on-demand • Agile • CDMI is superset of SRM • But using ReST+JSON, not SOAP
(Open) Standards • Standards promote interoperation and stability • Interoperation • Multiple (independent) implementations • Both Java and (C or C++)
The Case for Non-HEP Data • Benefit from non-HEP data • Outreachy stuff • Benefit to society (eg saving lives) • NGI interop (at compute) • Others…
Efficiencaciousness Goals Service • Availability • Performance • Grows as needed • Robust (no SPoF?) People • (Effective) support • Training • Expertise • Availability of…