web100 evaluation at ornl

WEB100 Evaluationat ORNL

Tom Dunigan [email protected]

Florence Fowler [email protected]

UT-BATTELLEU.S. Department of Energy Oak Ridge National Laboratory

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/

web100 evaluation at ornl

Documents