Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 1 ATLAS TDAQ Networking, Remote Compute Farms & Evaluating SFOs Richard Hughes-Jones The University of Manchester then “Talks”

Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 2 Network Purchase Review uConsidered the 4 networks in the Online system: DataCollection, Backend, Control, Management uThe review process was to: Derive the quantities and connectivity from each of the document sources Cross-check where possible that the information was consistant Examine what was ordered uDocuments used: network viso diagrams ROS Control and Data Networks Architecture Proposal 28 April, 2006 version 0.4 The order to IT for the network components Rack layouts uComponents & devices Ordered uInstallation well in hand

Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 3 Remote Computing Concepts ROB L2PU SFI PF Local Event Processing Farms ATLAS Detectors – Level 1 Trigger SFOs Mass storage Experimental Area CERN B513 Copenhagen Edmonton Krakow Manchester Amsterdam PF Remote Event Processing Farms PF lightpaths PF Data Collection Network Back End Network GÉANT Switch Level 2 Trigger Event Builders

Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 4 Tests & Traffic on Pionier uSummer 2006 uSet up Advanced Network Test GPS systems CERN, Krakow, Manc uExamined Network Performance PC-PC ANT-ANT

Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 5 CERN  Krakow: Throughput CERN  Krakow Krakow  CERN u800Mbit/s u20% Loss in the network u Mbit/s u40% Loss in the network u~3 * more re-ordering

Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 6 Remote Farms: TDAQ Initiative uAim of the Initiative: Develop the methodology Provide or identify the required “tool kits” Demonstrate Proof of Concepts for using remote Grid or compute farms in real time for ATLAS TDAQ applications. uNot guaranteed real-time services for ATLAS – yet uUse Cases: Calibration specific data from a small section of the experiment Monitoring data from several sub-detectors, allowing more detailed examination of a sub-detector performance Remote event storage Remote Event Filter Processing extend the computing capabilities of the Event Filter to remote Grid Farms uSecurity – Protect Point1 Application Gateways Links to Grid operations uDocument in Draft

Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 7 SFO Evaluation uSFO Buffers events from the Event Filter Transfers them to Mass Storage (CASTOR) uData movements: Receive events over the network from Event Filter specific data from a small section of the experiment Store them on one RAID5 disk sub-system in multiple streams When this is full swap writing to second RAID system Read data back from first RAID5 disk sub-system Send events over second network to mass storage at CERN uAs part of the RFI (Tender) uTest performance of RAID controllers

Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 8 RAID Controller Performance: Single Flow uElonex system had the Intel S5000PSL motherboard uTwo dual-core Intel Xeon CPU GHz CPUs u3Ware 9550SX-12MI 12 port SATA-RAID on PCI-e bus uSeven GB Hitachi Deskstar® E7K500 Configured as RAID5 64k byte stripe size uRAID5 ext2 file system uOne flow u2 GByte file: Read 2750 Mbit/s, Write 1215 Mbit/s Disk – Memory Read Speeds Memory - Disk Write Speeds

Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 9 RAID Controller Performance: Multiple Flows uRAID5 ext2 file system u8 GByte file: u2 Flows 180 Mbit/s /flow 5 Flows Mbit/s /flow uToo slow ! Memory - Disk Write 2 flows Memory - Disk Write 5 flows

Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 10 Any Questions?

Xmas Meeting, Manchester, Dec 2006, R. Hughes-Jones Manchester 11 Backup Slides