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WEB100 Evaluation at ORNL. Tom Dunigan thd@ornl.gov Florence Fowler ff8@ornl.gov. Web100 at ORNL. Why: DOE has large investment in high speed nets (ESnet) and distributed applications Evaluate Web100 for diagnosing network problems improving application performance ORNL evaluation
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WEB100 Evaluationat ORNL Tom Dunigan thd@ornl.gov Florence Fowler ff8@ornl.gov
Web100 at ORNL • Why: DOE has large investment in high speed nets (ESnet) and distributed applications • Evaluate Web100 for • diagnosing network problems • improving application performance • ORNL evaluation • GUI tests (buffer tuning) • use API to instrument network applications • validate Web100 stats
ORNL Web100 evaluation • Kernel overhead (negligible) • Web100 nodes at ORNL (100/1000E), UT (100E), home(10E) • plus SLAC and NCAR Web100 test sites • Tested over ESnet (OC3/OC12), OC3/VBR, cable modem, LANs (10/100/1000) • Validate with tcpdump/tcptrace • TCP flags at receiver ? (SACKEnabled, etc.) • SACKsRecvd
Web100 API experiments • Extend ttcp to report web100 variables at end of transfer • see why throughput was bad • modify netperf/iperf • Java applet bandwidth/client tester • fake WWW server provides html and applet • applet connects to bwserver • 3 sockets (control, bwin, bwout) • server reports Web100 variables to applet (window sizes, losses, RTT) • http://sunbirdj.ccs.ornl.gov:7123
Web100 and DOE -- NET100 • Net100 proposal -- PSC, LBNL, ORNL/UT ($1M/yr, 3 yrs) • Network-aware operating systems (autotuning) • Integrate Web100 with other network tools (NWS, NetLogger) • diagnostic tool for network problems • library to integrate Web100 and other network tools • data base for resource scheduling and “retentive TCP” • Optimize DOE network applications with Net100/Web100 • distributed applications (Grid, HEP, co-laboratories) • bulk transfers (Probe/HPSS ORNL-NERSC) • Transfer the technology
Future Web100 needs • Newer Linux kernel support • Other OS support (AIX for ORNL Probe/HPSS) • Future TCP variables • ECN • Vegas backoff • rate-halving • tunable recovery variables ? (cwnd multiplier/increment) • http://www.csm.ornl.gov:~dunigan/net100/