Max Mustermann Folientitel Veranstaltung Online Steering of HEP Applications Daniel Lorenz University of Siegen Cracow Grid Workshop – Daniel Lorenz Online Steering of HEP Applications CGW `06

Max Mustermann Vortragstitel Veranstaltung Overview Introduction Previous work HEP environment Layer architecture Steering functionality Online grid connection Conclusion and outlook Daniel Lorenz Online Steering of HEP Applications CGW `06 1

Max Mustermann Vortragstitel Veranstaltung Background: D-Grid German Grid initiative Funded by the Bundesministerium für Bildung und Forschung, BMBF 6 Community Grids and one common integration project HEP Community Grid (HEPCG) CGW `06 2 Daniel Lorenz Online Steering of HEP Applications

Max Mustermann Vortragstitel Veranstaltung Introduction New particle accelerator LHC at CERN (CH) Several different experiments Experiments struggle with huge amounts of data Deploy the LHC Computing Grid (LCG) Online steering tool for ATLAS experiment –Basic functionality just requires to change the job options –Advanced functionality can be added with source code instrumentation Online steering saves time and resources Daniel Lorenz Online Steering of HEP Applications CGW `06 3

Max Mustermann Vortragstitel Veranstaltung Introduction Typical cycle: –Configure job via job options –Submit job –Wait until job finished –Retrieve job output –Evaluation of the result Results may be meaningless because of –Improper job parameters (e.g cuts) –Semantic faults in job options, that are not found in test run Daniel Lorenz Online Steering of HEP Applications CGW `06 4

Max Mustermann Vortragstitel Veranstaltung Previous work Online steering in Reality Grid –Needs direct access to job –No secure communication Interactive communication in grids –Crossgrid –Interactive Grid Application Service Provider (I-GASP) Online steering in non-grid environments –CUMULVS –SCIRun –VISIT Daniel Lorenz Online Steering of HEP Applications CGW `06 5

Max Mustermann Vortragstitel Veranstaltung Environment (1) Daniel Lorenz Online Steering of HEP Applications Integration into ATLAS experiment software Athena and ROOT visualization toolkit Athena framework: –Event based –List of algorithms –Executed for every event –Easy to add new algorithms and services algorithm1 algorithm2 algorithm3 algorithm4 algorithm5 Svc1 Svc2 Athena Job job options CGW `06 6

Max Mustermann Vortragstitel Veranstaltung Environment (2) Integration into Athena: –New algorithm RM_Spy Job execution steering Most common results in ROOT files Restart with changed job options without resubmitting the job Only changes in job options (no source code changes) –New service RM_SteeringSvc Steering and monitoring of user defined data Source code instrumentation necessary Daniel Lorenz Online Steering of HEP Applications CGW `06 7

Max Mustermann Vortragstitel Veranstaltung Environment (3) Daniel Lorenz Visualization tool ROOT –Command line for C++ commands –Extendable with shared libraries Online Steering of HEP Applications CGW `06 8

Max Mustermann Vortragstitel Veranstaltung Layered architecture Daniel Lorenz communication visualization data consistency application data consistency communication data processing steering toolgrid job Online Steering of HEP Applications CGW `06 9

Max Mustermann Vortragstitel Veranstaltung Communication (1) Daniel Lorenz Secure communication –User side –Administrator side Cope with typical site configurations –Firewalls –Private IP Job runs on unknown host Connection by job id Hide complexity from user Dynamically deal with different site topologies Enable steering in as many cases as possible Online Steering of HEP Applications CGW `0610

Max Mustermann Vortragstitel Veranstaltung Communication (2) Daniel Lorenz Job registers itself to naming service (NS) e.g. R-GMA Steering tool gets location from NS Steering tool connects to communication service (CS) Connection between CS and job All connections use Globus GSSAPI Additional end to end authentication WN CE UI NS CS firewall steering tool job Online Steering of HEP Applications CGW `0611 private IP network internet

Max Mustermann Vortragstitel Veranstaltung Communication (3) Daniel Lorenz TCP connection message layer security layer grid connection security layer TCP connection message layer security layer grid connection security layer grid connection naming service steering toolcommunication servicegrid job Online Steering of HEP Applications CGW `0612

Max Mustermann Vortragstitel Veranstaltung Data consistency layer Registration of arbitrary data with serialize methods Manage all communication Regular call of a check method Daniel Lorenz Online Steering of HEP Applications CGW `0613

Max Mustermann Vortragstitel Veranstaltung Conclusion and outlook Goals: –Secure online connection –Easy integration into ATLAS software framework Status: –Prototype has been implemented –First release scheduled for November Outlook: –Extend for automated error detection and handling –Steering of parallel jobs –Communication between jobs Daniel Lorenz Online Steering of HEP Applications CGW `0614