Atlas:Analysis Challenge ST
Site Stress Test
Procedure
- Replication of target datasets accross the cloud
- Preparation of job
- Generation n jobs per site (Each job processes 1 dataset)
- Bulk submission to WMS (1 per site)
Test conditions
The testing framework is ganga-based. It is currently using LCG backend but it will soon be possible to use PANDA backend as well. Both POSIX I/O and "copy mode" may be used allowing performances comparaison of the 2 modes.
It uses regular AOD analysis in 14.2.20 with mc08*AOD*e*s*r5 DQ2 inputs
Input datasets are read from ATLASMCDISK and outputs are stored on ATLASUSERDISK (no special requirements there). Input data access is the main issue. No problem on data output
Required CPUtime :~ 1 day (typical job duration 5 h) GlueCEPolicyMaxCPUTime >= 1440
LAN saturation observed at ~ 3 Hz in case of 1 Gb network connection between WN and SE.
- GangaRobot
DA challenge runs similar to existing analysis functional tests : http://gangarobot.cern.ch/
See J.Elmsheuser's presentation (Nov. 5 08)
Site should pass the GangaRobot test successfully , especially :
Participation required at cloud and site level. Any site in the Tiers_of_ATLAS list can participate.
It is possible for sites to limit the number of jobs sent at a time. DA team is ready to take into account site constraints. DA team is open to any metrics
Target and metrics
- Nb of events : Few hundred up to 1000 jobs/site
- Rate (evt/s) : up to 15 Hz
- Efficiency (success/failure rate) : 80 %
- CPU utilization : CPUtime / Walltime > 50 %
Results
See
- ATLAS Twiki page : https://twiki.cern.ch/twiki/bin/view/Main/GangaSiteTests
- Results of analysis challenge performed on IT Cloud
- Results of DE Cloud
