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Providing information for capacity planning, network cost function, and understanding and testing network protocols for Middleware & Applications. Close collaboration with NRNs, DANTE, and the DataTAG project.
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WP7 Networking Richard Hughes-Jones
WP7: Networking for Grids • Grid Network monitoring • Provide information for Middleware & Applications – Network Cost Function • Understand the networks we use • Provide Information for capacity planning • Creation of schemas and publishing the monitoring data • Investigation of Protocols TCP and non-TCP • Testing the work of CS groups / IETF NOT inventing • Close technical collaboration with NRNs, DANTE and the DataTAG project • The High Bandwidth High Throughput Challenge • Investigation of end Host Networking and Disk sub-systems • To show what can be achieved on production networks with: • Multiple streams of TCP packets • Tuned TCP parameters • Different TCP stacks • Applying the knowledge to the real Grid user community
NetworkCost R-GMA Globus MDS Archive Raw Distributed Data Collector PCP PingEr IPerf UDPmon GridFTP NetworkCost Architecture Processing Collect And Storage Measure
CERN RAL NIKHEF IN2P3 CNAF CERN 46,75 77,78 44,87 35,44 RAL 7,46 2,44 7,12 4,35 NIKHEF 11,13 3,25 11,86 2,66 IN2P3 5,03 10,38 6,24 7,08 CNAF 4,5 6,53 4,04 13,08 NetworkCost functionality cost[][] = getNetworkCost (SE[], SE[]) FileSize= 11 MB
High throughput transfer challenges • Large amounts of data have to be transferred between Mass Storage Systems and CEs in Europe (and world wide!) • EU demonstration sent HEP data from CERN to NIKHEF/SARA at high rates • It was to show what can be achieved with: • Multiple streams of TCP packets • Tuned TCP parameters: • Interface txqueuelen 2000 • TCP buffer size to match the BW * rtt • Different TCP stacks: • Standard TCP • Fast TCP • Scalable TCP • Fair sharing between stacks • This highlights the results of close technical collaboration with NRNs, DANTE and other projects: DataTAG, Mb-NG, UK- Star- Nether- Light
NIKHEF CERN Demo Setup for the EDG Review • Shows data transfers from Mass Storage system at CERN to Mass Storage system at NIKHEF/SARA • Disk sub-system I/O bandwidth of ~70 MB/s • All systems have Gigabit Ethernet connectivity • Use GridFTP and Measure disk to disk performance GEANT SurfNet
Data over TCP Streams Raid0 Disk Raid0 Disk GridFTP GridFTP Demo Consisted of: Dante Monitoring Site Monitoring Node Monitoring
European Topology: NRNs, Geant, Sites Sara & NIKHEF SURFnet SuperJANET4 CERN
Throughput on the day ! The view from GÉANT – with thanks to Dante
Some Measurements of Throughput CERN -SARA • Using the GÉANT Backup Link • 1 GByte file transfers • Standard TCP • Average Throughput 167 Mbit/s • Users see 5 - 50 Mbit/s! • High-Speed TCP • Average Throughput 345 Mbit/s • Scalable TCP • Average Throughput 340 Mbit/s
What the Users Really find: • CERN – RAL using production GÉANT • CMS Tests 8 streams • 50 Mbit/s @ 15 MB buffer • Firewall 100 Mbit/s • NNW – SJ4 Access • 1 Gbit link
WP7 High Throughput Achievements • Close Collaboration with Dante • “Low” layer QOS testing over GEANT • LBE • IP premium • iGrid 2002 and ER 2002 : UDP with LBE • Network performances evaluation • EU Review 2003 : application level transfer with real data between EDG sites • proof of concept
Conclusions • More research on TCP stacks and its implementation is needed • ie HEP-style applied research - • Continue the collaboration with NRNs & Dante to: • Understand the behavior of National networks & GEANT backbone • Learn the benefits of QoS deployment • WP7 is taking the “Computer Science” research and knowledge of the TCP protocol & implementation and applying it to the network for real Grid users • Enabling Knowledge Transfer to sysadmins and end users • EDG release 1.4.x has configuration scripts for TCP parameters for SE and CE • Network tutorials for end users • Work with users – focus on 1 or 2 sites to try to get improvements