1. User-Level Performance Monitoring Programme Cees de Laat Hans Blom 1 of 6 Utrecht University

2. Contents of this talk This space is intentionally left blank 2 of 6

3. History DAS project –4 computer clusters on 4 different universities –Connected via "internet" and ATM –Prove QoS advantage –Management level WWW screen to see if links are up Dynacore –Remote Control –Video conferencing –Distributed databases –CORBA/Objectivity –Pseudo real time operation –Requirement minimal 10 Mbit/s Juelich - Utrecht –Weekdays often around 30 - 60 kbit –Was not a local problem, occurred in other German-Dutch projects

4. Tector 3 of 6

5. A/V DAQ REMOT Broker Dbs Teleoperation Jülich Remote TEXTOR Diagnostic DAQ Network services REMOT Broker Dbs DAQ Dbs REMOT broker Control Visualisation REMOT broker 4 of 6

6. Physics-UU to IPP-FZJ => 7 kingdoms –Netherlands »Physics dept »Campus net »SURFnet –Europe »TEN 155 –Germany »WINS/DFN »Juelich, Campus »Plasma Physics dept Multi Kingdom Problem 5 of 7 USA line 3 ms Jülich 17 ms 2.5 ms

7. rTPL package 6a of 7 Host rsh to initiate measurements collect data WWW server->applet ->brouwser Host user account, open for rsh modified netperf + ping user account, open for rsh modified netperf + ping idem

8. rTPL @ work Every hour: Controlling host contact host from list Netperf to other hosts for about 10 sec 40 ping's to other hosts Collect data Contact next host in list Builds matrix from/to Not all elements need to be filled data compressed in zip file Load on network ~ 1% User display User contacts WWW server at controlling host User gets applet Applet loads last zipped data file containing a week of data Older data also loadable Applet can average per week, per time of day, etc… 6b of 7

9. Demonstration This is the tricky part …. 6c of 7

10. Conclusions 6d of 7 Toolset rTPL Flexible package Unix knowledge essential (scripting) User friendly Can pinpoint performance problems if hosts well chosen Performance Network performance improved a lot (TEN 1.55 -> TEN 155) Still not sufficient for full scale virtual lab Modeling How does end to end relate to per hop performance tp1tp3tp2 Tp = f( tp1, tp2, tp3,... ) Host AHost B

11. Acknowledgments This work is supported by –TERENA Technical Programme –SURFnet bv –European Commission, DG XIII »Telematics Applications Programme Telematics for Research »RE 1008 REMOT »RE 4005 DYNACORE More info: http://www.phys.uu.nl/~wwwfi/nettest http://www.phys.uu.nl/~wwwfi/das http://www.phys.uu.nl/~wwwfi http://www.phys.uu.nl/~dynacore 7 of 7